POWER DRIVER FOR STEPPER MOTORS
INTEGRATED CIRCUITS
TMC2209 Datasheet
Step/Dir Drivers for Two-Phase Bipolar Stepper Motors up to 2.8A peak – StealthChop™ for Quiet
Movement – UART Interface Option – Sensorless Stall Detection StallGuard4.
APPLICATIONS
Compatible Design Upgrade
3D Printers
Printers, POS
Office and home automation
Textile, Sewing Machines
CCTV, Security
ATM, Cash recycler
HVAC
Battery Operated Equipment
4
FEATURES
AND
BENEFITS
2-phase stepper motors up to 2.8A coil current (peak), 2A RMS
STEP/DIR Interface with 8, 16, 32 or 64 microstep pin setting
Smooth Running 256 microsteps by MicroPlyer™ interpolation
StealthChop2™ silent motor operation
SpreadCycle™ highly dynamic motor control chopper
StallGuard4™ load and stall detection for StealthChop
CoolStep™ current control for energy savings up to 75%
Low RDSon, Low Heat-Up LS 170mΩ & HS 170mΩ (typ. at 25°C)
Voltage Range 4.75… 29V DC
Low Power Standby to fit standby energy regulations
Internal Sense Resistor option (no sense resistors required)
Passive Braking, Freewheeling, and automatic power down
Single Wire UART & OTP for advanced configuration options
Integrated Pulse Generator for standalone motion
Full Protection & Diagnostics
Compact QFN package with large heat slug
BLOCK DIAGRAM
TRINAMIC Motion Control GmbH & Co. KG
Hamburg, Germany
DESCRIPTION
The TMC2209 is an ultra-silent motor driver
IC for two phase stepper motors. TMC2209
pinning is compatible to a number of
legacy drivers as well as to the TMC2208.
TRINAMICs
sophisticated
StealthChop2
chopper ensures noiseless operation,
maximum efficiency and best motor torque.
Its fast current regulation and optional
combination with SpreadCycle allow highly
dynamic motion while adding. StallGuard
for sensorless homing. The integrated
power MOSFETs handle motor currents up
to 2A RMS with protection and diagnostic
features for robust and reliable operation.
A simple to use UART interface opens up
tuning
and
control
options.
Store
application tuning to OTP memory.
Industries’
most
advanced
STEP/DIR
stepper motor driver family upgrades
designs to noiseless and most precise
operation for cost-effective and highly
competitive solutions.
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
2
APPLICATION EXAMPLES: SIMPLE SOLUTIONS – HIGHLY EFFECTIVE
The TMC22xx family scores with power density, integrated power MOSFETs, smooth and quiet
operation, and a congenial simplicity. The TMC2209 covers a wide spectrum of applications from
battery systems to embedded applications with up to 2A motor current per coil. TRINAMICs unique
chopper modes SpreadCycle and StealthChop2 optimize drive performance. StealthChop reduces motor
noise to the point of silence at low velocities. Standby current reduction keeps costs for power
dissipation and cooling down. Extensive support enables rapid design cycles and fast time-to-market
with competitive products.
STANDALONE REPLACEMENT
FOR
LEGACY STEPPER DRIVER
0A+
S/D
ERROR, INDEX
TMC22xx
S
0A-
N
0B+
0B-
UART
INTERFACE FOR
FULL DIAGNOSTICS
AND
CONTROL
0A+
S/D
High-Level
Interface
CPU
UART
TMC22xx
0A0B+
0B-
Sense Resistors may be omitted
S
N
In this example, configuration is hard
wired via pins. Software based motion
control generates STEP and DIR
(direction) signals, INDEX and ERROR
signals report back status information.
A CPU operates the driver via step and
direction signals. It accesses diagnostic
information
and
configures
the
TMC2209 via the UART interface. The
CPU manages motion control and the
TMC2209 drives the motor and smoothens and optimizes drive performance.
The
TMC2209-EVAL
is
part
of
TRINAMICs universal evaluation board
system which provides a convenient
handling of the hardware as well as a
user-friendly
software
tool
for
evaluation. The TMC2209 evaluation
board system consists of three parts:
STARTRAMPE
(base
board),
ESELSBRÜCKE (connector board with
several test points and stand-alone
settings), and TMC2209-EVAL.
ORDER CODES
Order code
TMC2209-LA
TMC2209-LA-T
TMC2209-EVAL
ESELSBRÜCKE
LANDUNGSBRÜCKE
www.trinamic.com
PN
00-0173
00-0173-T
40-0169
40-0098
40-0167
Description
StealthChop standalone driver; QFN28 (RoHS compliant)
-T denotes tape on reel packing of devices
Evaluation board for TMC2209 stepper motor driver
Connector board fitting to Landungsbrücke
Baseboard for TMC2209-EVAL & further evaluation
boards
Size [mm2]
5x5
85 x 55
61 x 38
85 x 55
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
3
Table of Contents
1
PRINCIPLES OF OPERATION ......................... 4
1.1
1.2
1.3
1.4
1.5
KEY CONCEPTS ................................................ 5
CONTROL INTERFACES ..................................... 6
MOVING AND CONTROLLING THE MOTOR ........ 6
STEALTHCHOP2 & SPREADCYCLE DRIVER ....... 6
STALLGUARD4 – MECHANICAL LOAD SENSING .
....................................................................... 7
1.6
COOLSTEP – LOAD ADAPTIVE CURRENT
CONTROL ...................................................................... 7
1.7
AUTOMATIC STANDSTILL POWER DOWN......... 8
1.8
INDEX OUTPUT ................................................ 8
1.9
PRECISE CLOCK GENERATOR AND CLK INPUT... 8
2
PIN ASSIGNMENTS ........................................... 9
2.1
2.2
3
SAMPLE CIRCUITS ..........................................11
3.1
3.2
3.3
3.4
3.5
3.6
3.7
4
10
INTERNAL SENSE RESISTORS ..................... 53
11
STALLGUARD4 LOAD MEASUREMENT ....... 55
11.1
11.2
11.3
11.4
11.5
12
COOLSTEP OPERATION ................................. 57
12.1
12.2
12.3
13
STALLGUARD4 VS. STALLGUARD2 ................ 55
TUNING STALLGUARD4................................. 56
STALLGUARD4 UPDATE RATE ....................... 56
DETECTING A MOTOR STALL ......................... 56
LIMITS OF STALLGUARD4 OPERATION .......... 56
USER BENEFITS............................................. 57
SETTING UP FOR COOLSTEP .......................... 57
TUNING COOLSTEP ....................................... 59
STEP/DIR INTERFACE .................................... 60
13.1 TIMING ......................................................... 60
13.2 CHANGING RESOLUTION ............................... 61
13.3 MICROPLYER STEP INTERPOLATOR AND STAND
STILL DETECTION ....................................................... 62
13.4 INDEX OUTPUT ............................................. 63
14
INTERNAL STEP PULSE GENERATOR ......... 64
15
DRIVER DIAGNOSTIC FLAGS ...................... 65
15.1
15.2
15.3
15.4
TEMPERATURE MEASUREMENT ....................... 65
SHORT PROTECTION ...................................... 65
OPEN LOAD DIAGNOSTICS ........................... 66
DIAGNOSTIC OUTPUT ................................... 66
16
QUICK CONFIGURATION GUIDE ................ 67
17
EXTERNAL RESET ............................................. 71
REGISTER MAP .................................................19
18
CLOCK OSCILLATOR AND INPUT ............... 71
19
ABSOLUTE MAXIMUM RATINGS ................. 72
20
ELECTRICAL CHARACTERISTICS ................. 72
GENERAL REGISTERS .....................................20
VELOCITY DEPENDENT CONTROL ...................25
STALLGUARD CONTROL .................................26
SEQUENCER REGISTERS .................................28
CHOPPER CONTROL REGISTERS .....................29
STEALTHCHOP™ ..............................................35
6.1
6.2
6.3
6.4
6.5
6.6
6.7
7
ANALOG CURRENT SCALING VREF ............... 51
DATAGRAM STRUCTURE .................................15
CRC CALCULATION .......................................17
UART SIGNALS ............................................17
ADDRESSING MULTIPLE SLAVES ....................18
5.1
5.2
5.3
5.4
5.5
6
STANDARD APPLICATION CIRCUIT ................11
INTERNAL RDSON SENSING..........................11
5V ONLY SUPPLY..........................................12
CONFIGURATION PINS ..................................13
HIGH MOTOR CURRENT .................................13
LOW POWER STANDBY .................................14
DRIVER PROTECTION AND EME CIRCUITRY ...14
UART SINGLE WIRE INTERFACE ................15
4.1
4.2
4.3
4.4
5
PACKAGE OUTLINE TMC2209 ........................ 9
SIGNAL DESCRIPTIONS TMC2209 .................. 9
9.1
AUTOMATIC TUNING .....................................35
STEALTHCHOP OPTIONS ................................37
STEALTHCHOP CURRENT REGULATOR.............37
VELOCITY BASED SCALING ............................39
COMBINE STEALTHCHOP AND SPREADCYCLE .41
FLAGS IN STEALTHCHOP ...............................42
FREEWHEELING AND PASSIVE BRAKING ........43
SPREADCYCLE CHOPPER ...............................45
7.1
SPREADCYCLE SETTINGS ...............................46
8
SELECTING SENSE RESISTORS ....................49
9
MOTOR CURRENT CONTROL ........................50
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20.1
20.2
20.3
21
LAYOUT CONSIDERATIONS ......................... 78
21.1
21.2
21.3
21.4
22
OPERATIONAL RANGE ................................... 72
DC AND TIMING CHARACTERISTICS .............. 73
THERMAL CHARACTERISTICS.......................... 77
EXPOSED DIE PAD ........................................ 78
WIRING GND .............................................. 78
SUPPLY FILTERING........................................ 78
LAYOUT EXAMPLE TMC2209 ........................ 79
PACKAGE MECHANICAL DATA .................... 80
22.1
22.2
DIMENSIONAL DRAWINGS QFN28............... 80
PACKAGE CODES ........................................... 81
23
TABLE OF FIGURES ......................................... 82
24
REVISION HISTORY ....................................... 83
25
REFERENCES ...................................................... 83
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
1
4
Principles of Operation
The TMC22xx family of stepper drivers is intended as a drop-in upgrade for existing low-cost stepper
driver applications. Their silent drive technology StealthChop enables non-bugging motion control for
home and office applications. A highly efficient power stage enables high current from a tiny package.
The TMC2209 requires just a few control pins on its tiny package. It allows selection of the most
important setting: the desired microstep resolution. A choice of 8, 16, 32 or 64 microsteps, or from
fullstep up to 1/256 step adapts the driver to the capabilities of the motion controller.
STEP
DIR
5V Voltage
regulator
Step&Dir input
Analog Scaling
VREF
PDN/UART
Configuration
Interface
B. Dwersteg, ©
TRINAMIC 2016
UART interface
+ Register Block
DIAG
INDEX
opt. ext. clock
10-16MHz
CLK_IN
3.3V or 5V
I/O voltage
VCC_IO
VCP
OA2
BRA
stealthChop2
256 Microstep
Sequencer
Driver
Integrated
Rsense
S
N
stepper
motor
RSA
IREF
Connect directly
to GND plane
Use low inductivity SMD
type, e.g. 1206, 0.5W for
RSA and RSB
spreadCycle
Programmable
Diagnostic
Outputs
100µF
Low ESR type
Full Bridge A
OB1
coolStep
Full Bridge B
OB2
stallGuard4
Trimmed
CLK oscillator/
selector
BRB
RSB
Connect directly
to GND plane
opt. low power standby
opt. driver enable
GND
100n
ENN
Driver error
Index pulse
100n
OA1
STDBY
optional UART interface
MS2
SPREAD
100n
charge pump
IREF
Stand Still
Current
Reduction
Configuration
Memory (OTP)
microPlyer
MS1
+VM
VS
Step Pulse
Generator
Configuration
(GND or VCC_IO)
100n
16V
TMC2209
DIE PAD
Step and Direction
motion control
22n
50V
CPI
2.2µ
6.3V
5VOUT
Place near IC with
short path to die pad
CPO
VREF Analog current
scaling or leave
open
Even at low microstepping rate, the TMC2209 offers a number of unique enhancements over
comparable products: TRINAMICs sophisticated StealthChop2 chopper plus the microstep enhancement
MicroPlyer ensure noiseless operation, maximum efficiency and best motor torque. Its fast current
regulation and optional combination with SpreadCycle allow for highly dynamic motion. Protection
and diagnostic features support robust and reliable operation. A simple-to-use 8 bit UART interface
opens up more tuning and control options. Application specific tuning can be stored to on-chip OTP
memory. Industries’ most advanced step & direction stepper motor driver family upgrades designs to
noiseless and most precise operation for cost-effective and highly competitive solutions.
Figure 1.1 TMC2209 basic application block diagram
THREE MODES OF OPERATION:
OPTION 1: Standalone STEP/DIR Driver (Legacy Mode)
A CPU (µC) generates step & direction signals synchronized to additional motors and other
components within the system. The TMC2209 operates the motor as commanded by the configuration
pins and STEP/DIR signals. Motor run-current either is fixed, or set by the CPU using the analog input
VREF. The pin PDN_UART selects automatic standstill current reduction. Feedback from the driver to
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TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
5
the CPU is granted by the INDEX and DIAG output signals. Enable or disable the motor using the ENN
pin.
OPTION 2: Standalone STEP/DIR Driver with OTP pre-configuration
Additional options enabled by pre-programming OTP memory (label UART & OTP):
+
+
+
UART
OTP
Tuning of the chopper to the application for application tailored performance
Cost reduction by switching the driver to internal sense resistor mode
Adapting the automatic power down level and timing for best application efficiency
0A+
S/D
High-Level
Interface
CPU
ERROR, INDEX
TMC22xx
0A-
S
N
0B+
TXD only or bit
bang UART
Other drivers
0B-
External preprogramming
Figure 1.2 Stand-alone driver with pre-configuration
To enable the additional options, either one-time program the driver’s OTP memory, or store
configuration in the CPU and transfer it to the on-chip registers following each power-up. Operation
uses the same signals as Option 1. Programming does not need to be done within the application - it
can be executed during testing of the PCB! Alternatively, use bit-banging by CPU firmware to configure
the driver. Multiple drivers can be programmed at the same time using a single TXD line.
OPTION 3: STEP/DIR Driver with Full Diagnostics and Control
Similar to Option 2, but pin PDN_UART is connected to the CPU UART interface.
UART
Additional options (label UART):
+
+
+
+
+
Detailed diagnostics and thermal management
Passive braking and freewheeling for flexible, lowest power stop modes
More options for microstep resolution setting (fullstep to 256 microstep)
Software controlled motor current setting and more chopper options
Use StallGuard for sensorless homing and CoolStep for adaptive motor current and cool motor
This mode allows replacing all control lines like ENN, DIAG, INDEX, MS1, MS2, and analog current
setting VREF by a single interface line. This way, only three signals are required for full control: STEP,
DIR and PDN_UART. Even motion without external STEP pulses is provided by an internal
programmable step pulse generator: Just set the desired motor velocity. However, no ramping is
provided by the TMC2209.
1.1 Key Concepts
The TMC2209 implements advanced features which are exclusive to TRINAMIC products. These features
contribute toward greater precision, greater energy efficiency, higher reliability, smoother motion, and
cooler operation in many stepper motor applications.
StealthChop2™ No-noise, high-precision chopper algorithm for inaudible motion and inaudible
standstill of the motor. Allows faster motor acceleration and deceleration than
StealthChop™ and extends StealthChop to low stand still motor currents.
SpreadCycle™
High-precision cycle-by-cycle current control for highest dynamic movements.
MicroPlyer™
Microstep interpolator for obtaining full 256 microstep smoothness with lower
resolution step inputs starting from fullstep
StallGuard4™
Sensorless homing safes end switches and warns in case of motor overload
CoolStep™
Uses StallGuard measurement in order to adapt the motor current for best efficiency
and lowest heat-up of motor and driver
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TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
6
In addition to these performance enhancements, TRINAMIC motor drivers offer safeguards to detect
and protect against shorted outputs, output open-circuit, overtemperature, and undervoltage
conditions for enhancing safety and recovery from equipment malfunctions.
1.2 Control Interfaces
The TMC2209 supports both, discrete control lines for basic mode selection and a UART based single
wire interface with CRC checking. The UART interface automatically becomes enabled when correct
UART data is sent. When using UART, the pin selection may be disabled by control bits.
1.2.1
UART Interface
UART
The single wire interface allows unidirectional operation (for parameter setting only), or bi-directional
operation for full control and diagnostics. It can be driven by any standard microcontroller UART or
even by bit banging in software. Baud rates from 9600 Baud to 500k Baud or even higher (when
using an external clock) may be used. No baud rate configuration is required, as the TMC2209
automatically adapts to the masters’ baud rate. The frame format is identical to the intelligent
TRINAMIC controller & driver ICs TMC5130, TMC516x and TMC5072. A CRC checksum allows data
transmission over longer distance. For fixed initialization sequences, store the data including CRC into
the µC, thus consuming only a few 100 bytes of code for a full initialization. CRC may be ignored
during read access, if not desired. This makes CRC use an optional feature! The IC supports four
address settings to access up to four ICs on a single bus. Even more drivers can be programmed in
parallel by tying together all interface pins, in case no read access is required. An optional addressing
can be provided by analog multiplexers, like 74HC4066.
From a software point of view the TMC2209 is a peripheral with a number of control and status
registers. Most of them can either be written only or are read only. Some of the registers allow both,
read and write access. In case read-modify-write access is desired for a write only register, realize a
shadow register in master software.
1.3 Moving and Controlling the Motor
1.3.1
STEP/DIR Interface
The motor is controlled by a step and direction input. Active edges on the STEP input can be rising
edges or both rising and falling edges as controlled by a special mode bit (DEDGE). Using both edges
cuts the toggle rate of the STEP signal in half, which is useful for communication over slow interfaces
such as optically isolated interfaces. The state sampled from the DIR input upon an active STEP edge
determines whether to step forward or back. Each step can be a fullstep or a microstep, in which
there are 2, 4, 8, 16, 32, 64, 128, or 256 microsteps per fullstep. A step impulse with a low state on
DIR increases the microstep counter and a high decreases the counter by an amount controlled by the
microstep resolution. An internal table translates the counter value into the sine and cosine values
which control the motor current for microstepping.
1.3.2 Internal Step Pulse Generator
UART
Some applications do not require a precisely co-ordinate motion – the motor just is required to move
for a certain time and at a certain velocity. The TMC2209 comes with an internal pulse generator for
these applications: Just provide the velocity via UART interface to move the motor. The velocity sign
automatically controls the direction of the motion. However, the pulse generator does not integrate a
ramping function. Motion at higher velocities will require ramping up and ramping down the velocity
value via software.
STEP/DIR mode and internal pulse generator mode can be mixed in an application!
1.4 StealthChop2 & SpreadCycle Driver
StealthChop is a voltage-chopper based principle. It especially guarantees that the motor is absolutely
quiet in standstill and in slow motion, except for noise generated by ball bearings. Unlike other
voltage mode choppers, StealthChop2 does not require any configuration. It automatically learns the
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TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
7
best settings during the first motion after power up and further optimizes the settings in subsequent
motions. An initial homing sequence is sufficient for learning. Optionally, initial learning parameters
can be stored to OTP. StealthChop2 allows high motor dynamics, by reacting at once to a change of
motor velocity.
For highest velocity applications, SpreadCycle is an option to StealthChop2. It can be enabled via
input pin or via UART and OTP. StealthChop2 and SpreadCycle may even be used in a combined
configuration for the best of both worlds: StealthChop2 for no-noise stand still, silent and smooth
performance, SpreadCycle at higher velocity for high dynamics and highest peak velocity at low
vibration.
SpreadCycle is an advanced cycle-by-cycle chopper mode. It offers smooth operation and good
resonance dampening over a wide range of speed and load. The SpreadCycle chopper scheme
automatically integrates and tunes fast decay cycles to guarantee smooth zero crossing performance.
Benefits of using StealthChop2:
- Significantly improved microstepping with low cost motors
- Motor runs smooth and quiet
- Absolutely no standby noise
- Reduced mechanical resonance yields improved torque
1.5 StallGuard4 – Mechanical Load Sensing
StallGuard4 provides an accurate measurement of the load on the motor. It can be used for stall
detection as well as other uses at loads below those which stall the motor, such as CoolStep loadadaptive current reduction. This gives more information on the drive allowing functions like
sensorless homing and diagnostics of the drive mechanics.
1.6 CoolStep – Load Adaptive Current Control
coolStep drives the motor at the optimum current. It uses the stallGuard4 load measurement
information to adjust the motor current to the minimum amount required in the actual load situation.
This saves energy and keeps the components cool.
Benefits are:
- Energy efficiency
- Motor generates less heat
- Less or no cooling
- Use of smaller motor
- Less motor noise
power consumption decreased up to 75%
improved mechanical precision
improved reliability
less torque reserve required → cheaper motor does the job
Due to less energy exciting motor resonances
Figure 1.3 shows the efficiency gain of a 42mm stepper motor when using coolStep compared to
standard operation with 50% of torque reserve. coolStep is enabled above 60RPM in the example.
0,9
Efficiency with coolStep
0,8
Efficiency with 50% torque reserve
0,7
0,6
0,5
Efficiency
0,4
0,3
0,2
0,1
0
0
50
100
150
200
250
300
350
Velocity [RPM]
Figure 1.3 Energy efficiency with coolStep (example)
www.trinamic.com
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
8
1.7 Automatic Standstill Power Down
An automatic current reduction drastically reduces application power dissipation and cooling
requirements. Per default, the stand still current reduction is enabled by pulling PDN_UART input to
GND. It reduces standstill power dissipation to less than 33% by going to slightly more than half of
the run current.
Modify stand still current, delay time and decay via UART, or pre-programmed via internal OTP.
Automatic freewheeling and passive motor braking are provided as an option for stand still. Passive
braking reduces motor standstill power consumption to zero, while still providing effective
dampening and braking!
STEP
CURRENT
IRUN
IHOLD
RMS motor current trace with pin PDN=0
TPOWERDOWN IHOLDDELAY
power down power down
ramp time
delay time
t
Figure 1.4 Automatic Motor Current Power Down
1.8 Index Output
The index output gives one pulse per electrical rotation, i.e. one pulse per each four fullsteps. It
shows the internal sequencer microstep 0 position (MSTEP near 0). This is the power on position. In
combination with a mechanical home switch, a more precise homing is enabled.
1.9 Precise clock generator and CLK input
The TMC2209 provides a factory trimmed internal clock generator for precise chopper frequency and
performance. However, an optional external clock input is available for cases, where quartz precision
is desired, or where a lower or higher frequency is required. For safety, the clock input features
timeout detection, and switches back to internal clock upon fail of the external source.
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TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
2
9
Pin Assignments
The TMC2209 comes in a compact QFN package.
VS
BRB
OB1
OA1
BRA
VS
2.1 Package Outline TMC2209
26
25
24
23
22
3
19
2
20
1
6
© B. Dwersteg,
TRINAMIC
7
Pad=GND
9
10
11
12
13
OA2
STDBY
DIR
GND
VREF
STEP
VCC_IO
14
5VOUT
MS1_AD0
MS2_AD1
DIAG
INDEX
CLK
PDN_UART
8
15
16
5
17
18
TMC2209
QFN28
4
OB2
ENN
GND
CPO
CPI
VCP
SPREAD
27
21
28
Figure 2.1 TMC2209 Pinning Top View – type: QFN28, 5x5mm², 0.5mm pitch
2.2 Signal Descriptions TMC2209
Pin
OB2
Number
1
Type
ENN
2
DI
GND
CPO
CPI
VCP
3, 18
4
5
6
SPREAD
7
5VOUT
8
MS1_AD0
9
DI (pd)
MS2_AD1
10
DI (pd)
DIAG
11
DO
INDEX
12
DO
CLK
13
DI
PDN_UART
14
DIO
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DI (pd)
Function
Motor coil B output 2
Enable not input. The power stage becomes switched off (all motor
outputs floating) when this pin becomes driven to a high level.
GND. Connect to GND plane near pin.
Charge pump capacitor output.
Charge pump capacitor input. Tie to CPO using 22nF 50V capacitor.
Charge pump voltage. Tie to VS using 100nF capacitor.
Chopper mode selection: Low=StealthChop, High=SpreadCycle
(may be left unconnected)
Output of internal 5V regulator. Attach 2.2µF to 4.7µF ceramic
capacitor to GND near to pin for best performance. Provide the
shortest possible loop to the GND pad.
Microstep resolution configuration (internal pull-down resistors)
MS2, MS1: 00: 1/8, 01: 1/32, 10: 1/64 11: 1/16
For UART based configuration selection of UART Address 0…3
Diagnostic and StallGuard output. Hi level upon stall detection or
driver error. Reset error condition by ENN=high.
Configurable index output. Provides index pulse.
CLK input. Tie to GND using short wire for internal clock or supply
external clock.
Power down not control input (low = automatic standstill current
reduction).
Optional UART Input/Output. Power down function can be disabled
in UART mode.
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
Pin
VCC_IO
STEP
Number
15
16
Type
VREF
17
AI
DIR
19
DI (pd)
STDBY
20
DI (pd)
VS
22, 28
OA2
21
BRA
23
OA1
OB1
24
25
26
BRB
27
Exposed
die pad
-
www.trinamic.com
DI
unused
10
Function
3.3V to 5V IO supply voltage for all digital pins.
STEP input
Analog reference voltage for current scaling or reference current for
use of internal sense resistors (optional mode)
DIR input (internal pull-down resistor)
STANDBY input. Pull up to disable driver internal supply regulator.
This will bring the driver into a low power dissipation state.
100kOhm pulldown. (may be left unconnected)
Hint: Also shut down VREF voltage and ENN to 0V during standby.
Motor supply voltage. Provide filtering capacity near pin with
shortest possible loop to GND pad.
Motor coil A output 2
Sense resistor connection for coil A. Place sense resistor to GND near
pin. Tie to GND when using internal sense resistor.
Motor coil A output 1
May be connected to GND for better PCB routing
Motor coil B output 1
Sense resistor connection for coil B. Place sense resistor to GND near
pin. Tie to GND when using internal sense resistor.
Connect the exposed die pad to a GND plane. Provide as many as
possible vias for heat transfer to GND plane. Serves as GND pin for
power drivers and analogue circuitry.
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
3
11
Sample Circuits
The sample circuits show the connection of external components in different operation and supply
modes. The connection of the bus interface and further digital signals is left out for clarity.
STEP
DIR
5V Voltage
regulator
Step&Dir input
Analog Scaling
PDN/UART
Configuration
Memory (OTP)
B. Dwersteg, ©
TRINAMIC 2016
DIAG
INDEX
opt. ext. clock
10-16MHz
CLK_IN
3.3V or 5V
I/O voltage
VCC_IO
CPI
VCP
OA2
BRA
Driver
Integrated
Rsense
S
N
stepper
motor
RSA
IREF
Connect directly
to GND plane
Use low inductivity SMD
type, e.g. 1206, 0.5W for
RSA and RSB
spreadCycle
Programmable
Diagnostic
Outputs
100µF
Low ESR type
Full Bridge A
OB1
coolStep
Full Bridge B
OB2
stallGuard4
Trimmed
CLK oscillator/
selector
BRB
RSB
Connect directly
to GND plane
opt. low power standby
opt. driver enable
GND
ENN
100n
STDBY
Index pulse
256 Microstep
Sequencer
100n
OA1
stealthChop2
Configuration
Interface
UART interface
+ Register Block
Driver error
100n
charge pump
IREF
Stand Still
Current
Reduction
microPlyer
optional UART interface
MS2
SPREAD
+VM
VS
VREF
Configuration
(GND or VCC_IO)
100n
16V
TMC2209
Step Pulse
Generator
MS1
22n
50V
DIE PAD
Step and Direction
motion control
CPO
2.2µ
6.3V
5VOUT
Place near IC with
short path to die pad
VREF Analog current
scaling or leave
open
3.1 Standard Application Circuit
Figure 3.1 Standard application circuit
The standard application circuit uses a minimum set of additional components. Two sense resistors
set the motor coil current. See chapter 8 to choose the right sense resistors. Use low ESR capacitors
for filtering the power supply. The capacitors need to cope with the current ripple cause by chopper
operation. A minimum capacity of 100µF near the driver is recommended for best performance.
Current ripple in the supply capacitors also depends on the power supply internal resistance and
cable length. VCC_IO can be supplied from 5VOUT, or from an external source, e.g. a 3.3V regulator.
Basic layout hints
Place sense resistors and all filter capacitors as close as possible to the related IC pins. Use a solid
common GND for all GND connections, also for sense resistor GND. Connect 5VOUT filtering capacitor
directly to 5VOUT and the die pad. See layout hints for more details. Low ESR electrolytic capacitors
are recommended for VS filtering.
3.2 Internal RDSon Sensing
For cost critical or space limited applications, sense resistors can be omitted. For internal current
sensing, a reference current set by a tiny external resistor programs the output current. For calculation
of the reference resistor, refer chapter 9.1.
Attention
Be sure to switch the IC to RDSon mode, before enabling drivers: Set otp_internalRsense = 1.
www.trinamic.com
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
12
STEP
Step and Direction
motion control
DIR
Configuration
Interface
PDN/UART
B. Dwersteg, ©
TRINAMIC 2016
UART interface
+ Register Block
DIAG
INDEX
opt. ext. clock
10-16MHz
CLK_IN
3.3V or 5V
I/O voltage
VCC_IO
100µF
IREF
Low ESR type
OA1
Full Bridge A
256 Microstep
Sequencer
OA2
BRA
Integrated
Rsense
Driver
S
N
stepper
motor
Connect directly
to GND plane
IREF
Attention:
Start with ENN=high!
Set GCONF.1 or OTP0.6
prior to enabling the driver!
spreadCycle
Programmable
Diagnostic
Outputs
100n
charge pump
stealthChop2
microPlyer
MS2
100n
Analog Scaling
Stand Still
Current
Reduction
Configuration
Memory (OTP)
SPREAD
Driver error
CPO
VREF
5V Voltage
regulator
Step&Dir input
MS1
Index pulse
+VM
TMC2209
VREF
OB1
coolStep
Full Bridge B
OB2
stallGuard4
Trimmed
CLK oscillator/
selector
BRB
Connect directly
to GND plane
opt. low power standby
opt. driver enable
GND
ENN
DIE PAD
100n
STDBY
optional UART interface
100n
16V
VS
Step Pulse
Generator
Configuration
(GND/open or VCC_IO)
22n
50V
VCP
RREF
5VOUT
2.2µ
6.3V
CPI
Place near IC with
short path to die pad
Figure 3.2 Application circuit using RDSon based sensing
STEP
DIR
5V Voltage
regulator
Step&Dir input
Configuration
Interface
PDN/UART
B. Dwersteg, ©
TRINAMIC 2016
UART interface
+ Register Block
INDEX
opt. ext. clock
10-16MHz
CLK_IN
3.3V or 5V
I/O voltage
VCC_IO
256 Microstep
Sequencer
100n
VCP
Low ESR type
Full Bridge A
Driver
OA2
BRA
Integrated
Rsense
S
RSA
IREF
Connect directly
to GND plane
Use low inductivity SMD
type, e.g. 1206, 0.5W for
RSA and RSB
OB1
coolStep
Full Bridge B
OB2
stallGuard4
Trimmed
CLK oscillator/
selector
100µF
OA1
spreadCycle
Programmable
Diagnostic
Outputs
BRB
RSB
Connect directly
to GND plane
opt. low power standby
opt. driver enable
GND
ENN
100n
Figure 3.3 5V only operation
www.trinamic.com
IREF
STDBY
Driver error
100n
charge pump
stealthChop2
microPlyer
MS2
SPREAD
Index pulse
CPO
Analog Scaling
Stand Still
Current
Reduction
Configuration
Memory (OTP)
MS1
DIAG
4.7-5.4V
VS
VREF
optional UART interface
100n
16V
TMC2209
Step Pulse
Generator
Configuration
(GND/open or VCC_IO)
22n
50V
DIE PAD
Step and Direction
motion control
10R
Optional – bridges the internal 5V
reference – leave away if standby is
desired
VREF
10µ
6.3V
5VOUT
Place near IC with
short path to die pad
CPI
3.3 5V Only Supply
N
stepper
motor
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
13
While the standard application circuit is limited to roughly 5.2 V lower supply voltage, a 5 V only
application lets the IC run from a 5 V +/-5% supply. In this application, linear regulator drop must be
minimized. Therefore, the internal 5V regulator is filtered with a higher capacitance. An optional
resistor bridges the internal 5V regulator by connecting 5VOUT to the external power supply. This RC
filter keeps chopper ripple away from 5VOUT. With this resistor, the external supply is the reference
for the absolute motor current and must not exceed 5.5V. Standby function will not work in this
application, because the 5V regulator is bridged.
3.4 Configuration Pins
The TMC2209 provides four configuration pins. These pins allow quick configuration for standalone
operation. Several additional options can be set by OTP programming. In UART mode, the
configuration pins can be disabled in order to set a different configuration via registers.
PDN_UART: CONFIGURATION OF STANDSTILL POWER DOWN
PDN_UART
GND
VCC_IO
UART interface
Current Setting
Enable automatic power down in standstill periods
Disable
When using the UART interface, the configuration pin should be disabled via
GCONF.pdn_disable = 1. Program IHOLD as desired for standstill periods.
MS1/MS2: CONFIGURATION OF MICROSTEP RESOLUTION FOR STEP INPUT
MS2
GND
GND
VCC_IO
VCC_IO
MS1
GND
VCC_IO
GND
VCC_IO
Microstep Setting
8 microsteps
32 microsteps (different to TMC2208!)
64 microsteps (different to TMC2208!)
16 microsteps
SPREAD: SELECTION OF CHOPPER MODE
SPREAD
GND or
Pin open / not
available
VCC_IO
Chopper Setting
StealthChop is selected. Automatic switching to SpreadCycle in dependence of
the step frequency can be programmed via OTP.
SpreadCycle operation.
3.5 High Motor Current
When operating at a high motor current, the driver power dissipation due to MOSFET switch onresistance significantly heats up the driver. This power dissipation will significantly heat up the PCB
cooling infrastructure, if operated at an increased duty cycle. This in turn leads to a further increase of
driver temperature. An increase of temperature by about 100°C increases MOSFET resistance by
roughly 50%. This is a typical behavior of MOSFET switches. Therefore, under high duty cycle, high
load conditions, thermal characteristics have to be carefully taken into account, especially when
increased environment temperatures are to be supported. Refer the thermal characteristics and the
layout hints for more information. As a thumb rule, thermal properties of the PCB design become
critical for the tiny QFN 5mm x 5mm package at or above 1.4A RMS motor current for increased
periods of time. Keep in mind that resistive power dissipation rises with the square of the motor
current. On the other hand, this means that a small reduction of motor current significantly saves heat
dissipation and energy.
Pay special attention to good thermal properties of your PCB layout, when going for 1.4A RMS current
or more.
www.trinamic.com
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
14
An effect which might be perceived at medium motor velocities and motor sine wave peak currents
above roughly 2A peak is a slight sine distortion of the current wave when using SpreadCycle. It
results from an increasing negative impact of parasitic internal diode conduction, which in turn
negatively influences the duration of the fast decay cycle of the SpreadCycle chopper. This is, because
the current measurement does not see the full coil current during this phase of the sine wave,
because an increasing part of the current flows directly from the power MOSFETs’ drain to GND and
does not flow through the sense resistor. This effect with most motors does not negatively influence
the smoothness of operation, as it does not impact the critical current zero transition. The effect does
not occur with StealthChop.
3.6 Low Power Standby
Battery powered applications, and mains powered applications conforming to standby energy saving
rules, often require a standby operation, where the power-supply remains on, but current draw goes
down to a low value. The TMC2209 supports standby operation of roughly 2mW (at 12V supply), or
TPWMTHRS
- CoolStep is enabled, if configured (only with StealthChop)
- Stall output signal on pin DIAG is enabled
SGTHRS
Detection threshold for stall. The StallGuard value SG_RESULT
becomes compared to the double of this threshold.
A stall is signaled with
SG_RESULT ≤ SGTHRS*2
StallGuard result. SG_RESULT becomes updated with each
fullstep, independent of TCOOLTHRS and SGTHRS. A higher
value signals a lower motor load and more torque headroom.
Intended for StealthChop mode, only. Bits 9 and 0 will always
show 0. Scaling to 10 bit is for compatibility to StallGuard2.
CoolStep configuration
See separate table!
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
5.3.1
27
COOLCONF – Smart Energy Control CoolStep
0X42: COOLCONF – SMART ENERGY CONTROL COOLSTEP AND STALLGUARD2
Bit
…
15
Name
Function
Comment
seimin
14
13
sedn1
sedn0
minimum current for
smart current control
current down step
speed
12
11
10
9
8
7
6
5
4
3
2
1
0
semax3
semax2
semax1
semax0
seup1
seup0
semin3
semin2
semin1
semin0
0: 1/2 of current setting (IRUN)
1: 1/4 of current setting (IRUN)
%00: For each 32 StallGuard4 values decrease by one
%01: For each 8 StallGuard4 values decrease by one
%10: For each 2 StallGuard4 values decrease by one
%11: For each StallGuard4 value decrease by one
set to 0
If the StallGuard4 result is equal to or above
(SEMIN+SEMAX+1)*32, the motor current becomes
decreased to save energy.
%0000 … %1111: 0 … 15
set to 0
Current increment steps per measured StallGuard2 value
%00 … %11: 1, 2, 4, 8
set to 0
If the StallGuard4 result falls below SEMIN*32, the motor
current becomes increased to reduce motor load angle.
%0000: smart current control CoolStep off
%0001 … %1111: 1 … 15
www.trinamic.com
reserved
StallGuard2 hysteresis
value for smart current
control
reserved
current up step width
reserved
minimum StallGuard2
value for smart current
control and
smart current enable
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
28
5.4 Sequencer Registers
The sequencer registers have a pure informative character and are read-only. They help for special
cases like storing the last motor position before power off in battery powered applications.
MICROSTEPPING CONTROL REGISTER SET (0X60…0X6B)
R/W
Addr
n
Register
R
0x6A
10
MSCNT
R
0x6B
9
+
9
www.trinamic.com
MSCURACT
Description / bit names
Microstep counter. Indicates actual position
in the microstep table for CUR_A. CUR_B uses
an offset of 256 into the table. Reading out
MSCNT allows determination of the motor
position within the electrical wave.
bit 8… 0:
CUR_A (signed):
Actual microstep current for
motor phase A as read from the
internal sine wave table (not
scaled by current setting)
bit 24… 16: CUR_B (signed):
Actual microstep current for
motor phase B as read from the
internal sine wave table (not
scaled by current setting)
Range [Unit]
0…1023
+/-0...255
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
29
5.5 Chopper Control Registers
DRIVER REGISTER SET (0X6C…0X7F)
R/W
Addr
n
Register
RW
0x6C
32
CHOPCONF
R
0x6F
32
DRV_
STATUS
RW
0x70
22
PWMCONF
R
R
0x71
0x72
9+8
8+8
www.trinamic.com
PWM_SCALE
PWM_AUTO
Description / bit names
Chopper and driver configuration
See separate table!
Driver status flags and current level read
back
See separate table!
StealthChop PWM chopper configuration
See separate table!
Results of StealthChop amplitude regulator.
These values can be used to monitor
automatic PWM amplitude scaling (255=max.
voltage).
bit 7… 0
PWM_SCALE_SUM:
Actual PWM duty cycle. This
value is used for scaling the
values CUR_A and CUR_B read
from the sine wave table.
bit 24… 16 PWM_SCALE_AUTO:
9 Bit signed offset added to the
calculated PWM duty cycle. This
is the result of the automatic
amplitude regulation based on
current measurement.
These automatically generated values can be
read out in order to determine a default /
power up setting for PWM_GRAD and
PWM_OFS.
bit 7… 0
PWM_OFS_AUTO:
Automatically determined offset
value
bit 23… 16 PWM_GRAD_AUTO:
Automatically
determined
gradient value
Range [Unit]
Reset default=
0x10000053
Reset default=
0xC10D0024
0…255
signed
-255…+255
0…255
0…255
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
5.5.1
30
CHOPCONF – Chopper Configuration
0X6C: CHOPCONF – CHOPPER CONFIGURATION
Bit
31
Name
diss2vs
30
diss2g
29
dedge
28
intpol
interpolation to 256
microsteps
27
26
25
24
mres3
mres2
mres1
mres0
MRES
micro step resolution
23
22
21
20
19
18
17
-
reserved
vsense
16
15
tbl1
tbl0
sense resistor voltage
based current scaling
TBL
blank time select
14
13
12
11
10
9
8
7
-
reserved
hend3
hend2
hend1
hend0
HEND
hysteresis low value
OFFSET
sine wave offset
6
5
4
hstrt2
hstrt1
hstrt0
HSTRT
hysteresis start value
added to HEND
www.trinamic.com
Function
Low side short
protection disable
short to GND
protection disable
enable double edge
step pulses
Comment
0: Short protection low side is on
1: Short protection low side is disabled
0: Short to GND protection is on
1: Short to GND protection is disabled
1: Enable step impulse at each step edge to reduce step
frequency requirement. This mode is not compatible
with the step filtering function (multistep_filt)
1: The actual microstep resolution (MRES) becomes
extrapolated to 256 microsteps for smoothest motor
operation.
(Default: 1)
%0000:
Native 256 microstep setting.
%0001 … %1000:
128, 64, 32, 16, 8, 4, 2, FULLSTEP
Reduced microstep resolution.
The resolution gives the number of microstep entries per
sine quarter wave.
When choosing a lower microstep resolution, the driver
automatically uses microstep positions which result in a
symmetrical wave.
Number of microsteps per step pulse = 2^MRES
(Selection by pins unless disabled by GCONF.
mstep_reg_select)
set to 0
0: Low sensitivity, high sense resistor voltage
1: High sensitivity, low sense resistor voltage
%00 … %11:
Set comparator blank time to 16, 24, 32 or 40 clocks
Hint: %00 or %01 is recommended for most applications
(Default: OTP)
set to 0
%0000 … %1111:
Hysteresis is -3, -2, -1, 0, 1, …, 12
(1/512 of this setting adds to current setting)
This is the hysteresis value which becomes used for the
hysteresis chopper.
(Default: OTP, resp. 5 in StealthChop mode)
%000 … %111:
Add 1, 2, …, 8 to hysteresis low value HEND
(1/512 of this setting adds to current setting)
Attention: Effective HEND+HSTRT ≤ 16.
Hint: Hysteresis decrement is done each 16 clocks
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
0X6C: CHOPCONF – CHOPPER CONFIGURATION
Bit
Name
Function
Comment
(Default: OTP, resp. 0 in StealthChop mode)
3
2
1
0
toff3
toff2
toff1
toff0
TOFF off time
and driver enable
Off time setting controls duration of slow decay phase
NCLK= 24 + 32*TOFF
%0000: Driver disable, all bridges off
%0001: 1 – use only with TBL ≥ 2
%0010 … %1111: 2 … 15
(Default: OTP, resp. 3 in StealthChop mode)
www.trinamic.com
31
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
5.5.2
32
PWMCONF – Voltage PWM Mode StealthChop
0X70: PWMCONF – VOLTAGE MODE PWM STEALTHCHOP
Bit
31
30
29
28
Name
PWM_LIM
Function
PWM automatic scale
amplitude limit when
switching on
27
26
25
24
PWM_REG
Regulation loop
gradient
23
22
21
20
freewheel1
freewheel0
reserved
reserved
Allows different
standstill modes
19
pwm_
autograd
PWM automatic
gradient adaptation
18
pwm_
autoscale
PWM automatic
amplitude scaling
17
pwm_freq1
PWM frequency
www.trinamic.com
Comment
Limit for PWM_SCALE_AUTO when switching back from
SpreadCycle to StealthChop. This value defines the upper
limit for bits 7 to 4 of the automatic current control
when switching back. It can be set to reduce the current
jerk during mode change back to StealthChop.
It does not limit PWM_GRAD or PWM_GRAD_AUTO offset.
(Default = 12)
User defined maximum PWM amplitude change per half
wave when using pwm_autoscale=1. (1…15):
1: 0.5 increments (slowest regulation)
2: 1 increment (default with OTP2.1=1)
3: 1.5 increments
4: 2 increments
…
8: 4 increments (default with OTP2.1=0)
...
15: 7.5 increments (fastest regulation)
set to 0
set to 0
Stand still option when motor current setting is zero
(I_HOLD=0).
%00: Normal operation
%01: Freewheeling
%10: Coil shorted using LS drivers
%11: Coil shorted using HS drivers
0
Fixed value for PWM_GRAD
(PWM_GRAD_AUTO = PWM_GRAD)
1
Automatic tuning (only with pwm_autoscale=1)
PWM_GRAD_AUTO is initialized with PWM_GRAD
and becomes optimized automatically during
motion.
Preconditions
1. PWM_OFS_AUTO has been automatically
initialized. This requires standstill at IRUN for
>130ms in order to a) detect standstill b) wait >
128 chopper cycles at IRUN and c) regulate
PWM_OFS_AUTO so that
-1 < PWM_SCALE_AUTO < 1
2. Motor running and 1.5 * PWM_OFS_AUTO <
PWM_SCALE_SUM < 4* PWM_OFS_AUTO and
PWM_SCALE_SUM < 255.
Time required for tuning PWM_GRAD_AUTO
About 8 fullsteps per change of +/-1.
0
User defined feed forward PWM amplitude. The
current settings IRUN and IHOLD have no influence!
The resulting PWM amplitude (limited to 0…255) is:
PWM_OFS * ((CS_ACTUAL+1) / 32)
+ PWM_GRAD * 256 / TSTEP
1
Enable automatic current control (Reset default)
%00: fPWM=2/1024 fCLK
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
33
0X70: PWMCONF – VOLTAGE MODE PWM STEALTHCHOP
Bit
16
Name
pwm_freq0
Function
selection
15
14
13
12
11
10
9
8
PWM_
GRAD
User defined amplitude
gradient
7
6
5
4
3
2
1
0
PWM_
OFS
User defined amplitude
(offset)
Comment
%01: fPWM=2/683 fCLK
%10: fPWM=2/512 fCLK
%11: fPWM=2/410 fCLK
Velocity dependent gradient for PWM amplitude:
PWM_GRAD * 256 / TSTEP
This value is added to PWM_AMPL to compensate for
the velocity-dependent motor back-EMF.
With automatic scaling (pwm_autoscale=1) the value is
used for first initialization, only. Set PWM_GRAD to the
application specific value (it can be read out from
PWM_GRAD_AUTO) to speed up the automatic tuning
process. An approximate value can be stored to OTP by
programming OTP_PWM_GRAD.
User defined PWM amplitude offset (0-255) related to full
motor current (CS_ACTUAL=31) in stand still.
(Reset default=36)
When using automatic scaling (pwm_autoscale=1) the
value is used for initialization, only. The autoscale
function starts with PWM_SCALE_AUTO=PWM_OFS and
finds the required offset to yield the target current
automatically.
PWM_OFS = 0 will disable scaling down motor current
below a motor specific lower measurement threshold.
This setting should only be used under certain
conditions, i.e. when the power supply voltage can vary
up and down by a factor of two or more. It prevents
the motor going out of regulation, but it also prevents
power down below the regulation limit.
PWM_OFS > 0 allows automatic scaling to low PWM duty
cycles even below the lower regulation threshold. This
allows low (standstill) current settings based on the
actual (hold) current scale (register IHOLD_IRUN).
www.trinamic.com
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
5.5.3
34
DRV_STATUS – Driver Status Flags
0X6F: DRV_STATUS – DRIVER STATUS FLAGS AND CURRENT LEVEL READ BACK
Bit
31
Name
stst
Function
standstill indicator
30
stealth
StealthChop indicator
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
-
reserved
Comment
This flag indicates motor stand still in each operation
mode. This occurs 2^20 clocks after the last step pulse.
1: Driver operates in StealthChop mode
0: Driver operates in SpreadCycle mode
Ignore these bits.
-
reserved
Ignore these bits.
CS_
ACTUAL
actual motor current /
smart energy current
Actual current control scaling, for monitoring the
function of the automatic current scaling.
-
reserved
Ignore these bits.
t157
t150
t143
t120
olb
6
ola
5
s2vsb
4
s2vsa
3
s2gb
2
s2ga
1
ot
157°C comparator
150°C comparator
143°C comparator
120°C comparator
open load indicator
phase B
open load indicator
phase A
low side short
indicator phase B
low side short
indicator phase A
short to ground
indicator phase B
short to ground
indicator phase A
overtemperature flag
0
otpw
1: Temperature threshold is exceeded
1: Temperature threshold is exceeded
1: Temperature threshold is exceeded
1: Temperature threshold is exceeded
1: Open load detected on phase A or B.
Hint: This is just an informative flag. The driver takes no
action upon it. False detection may occur in fast motion
and standstill. Check during slow motion, only.
1: Short on low-side MOSFET detected on phase A or B.
The driver becomes disabled. The flags stay active, until
the driver is disabled by software (TOFF=0) or by the
ENN input. Flags are separate for both chopper modes.
1: Short to GND detected on phase A or B. The driver
becomes disabled. The flags stay active, until the driver
is disabled by software (TOFF=0) or by the ENN input.
Flags are separate for both chopper modes.
1: The selected overtemperature limit has been reached.
Drivers become disabled until otpw is also cleared due
to cooling down of the IC.
The overtemperature flag is common for both bridges.
1: The selected overtemperature pre-warning threshold
is exceeded.
The overtemperature pre-warning flag is common for
both bridges.
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overtemperature prewarning flag
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
6
35
StealthChop™
StealthChop is an extremely quiet mode of operation for stepper motors. It is based on a
voltage mode PWM. In case of standstill and at low velocities, the motor is absolutely
noiseless. Thus, StealthChop operated stepper motor applications are very suitable for
indoor or home use. The motor operates absolutely free of vibration at low velocities.
With StealthChop, the motor current is applied by driving a certain effective voltage into
the coil, using a voltage mode PWM. With the enhanced StealthChop2, the driver automatically adapts
to the application for best performance. No more configurations are required. Optional configuration
allows for tuning the setting in special cases, or for storing initial values for the automatic adaptation
algorithm. For high velocity consider SpreadCycle in combination with StealthChop.
Figure 6.1 Motor coil sine wave current with StealthChop (measured with current probe)
6.1 Automatic Tuning
StealthChop2 integrates an automatic tuning procedure (AT), which adapts the most important
operating parameters to the motor automatically. This way, StealthChop2 allows high motor dynamics
and supports powering down the motor to very low currents. Just two steps have to be respected by
the motion controller for best results: Start with the motor in standstill, but powered with nominal
run current (AT#1). Move the motor at a medium velocity, e.g. as part of a homing procedure (AT#2).
Figure 6.2 shows the tuning procedure.
Border conditions in for AT#1 and AT#2 are shown in the following table:
AUTOMATIC TUNING TIMING AND BORDER CONDITIONS
Step
AT#1
Parameter
PWM_
OFS_AUTO
AT#2
PWM_
GRAD_AUTO
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Conditions
- Motor in standstill and actual current scale (CS) is
identical to run current (IRUN).
- If standstill reduction is enabled (pin PDN_UART=0),
an initial step pulse switches the drive back to run
current.
- Pins VS and VREF at operating level.
- Motor must move at a velocity, where a significant
amount of back EMF is generated and where the full
run current can be reached. Conditions:
- 1.5 * PWM_OFS_AUTO
<
PWM_SCALE_SUM
<
4 * PWM_OFS_AUTO
- PWM_SCALE_SUM < 255.
Hint: A typical range is 60-300 RPM. Determine best
conditions with the evaluation board and monitor
PWM_SCALE_AUTO going down to zero during tuning.
Duration
≤ 2^20+2*2^18 tCLK,
≤ 130ms
(with internal clock)
8 fullsteps are required
for a change of +/-1.
For a typical motor with
PWM_GRAD_AUTO
optimum at 64 or less, up
to 400 fullsteps are
required when starting
from OTP default 14.
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
36
Power Up
PWM_GRAD_AUTO becomes
initialized by OTP
Driver Enabled?
N
Y
Stand still
N
Y
N
AT#1
Driver Enabled?
Standstill reduction enabled?
Y
Issue (at least) a single step
pulse and stop again, to
power motor to run current
stealthChop2 regulates to nominal
current and stores result to
PWM_OFS_AUTO
(Requires stand still for >130ms)
PWM_
GRAD_AUTO stored
in OTP?
Y
N
AT#2
Homing
Move the motor, e.g. for homing.
Include a constant, medium velocity
ramp segment.
stealthChop2 regulates to nominal
current and optimizes PWM_GRAD_AUTO
(requires 8 fullsteps per change of 1,
typically a few 100 fullsteps in sum)
Ready
stealthChop2 settings are optimized!
Option with UART
Store PWM_GRAD_AUTO or
write to OTP for faster
tuning procedure
stealthChop2 keeps tuning during
subsequent motion and stand still periods
adapting to motor heating, supply
variations, etc.
Figure 6.2 StealthChop2 automatic tuning procedure
Attention
Modifying VREF or the supply voltage VS invalidates the result of the automatic tuning process. Motor
current regulation cannot compensate significant changes until next AT#1 phase. Automatic tuning
adapts to changed conditions whenever AT#1 and AT#2 conditions are fulfilled in the later operation.
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TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
37
6.2 StealthChop Options
UART
In order to match the motor current to a certain level, the effective PWM voltage becomes scaled
depending on the actual motor velocity. Several additional factors influence the required voltage level
to drive the motor at the target current: The motor resistance, its back EMF (i.e. directly proportional
to its velocity) as well as the actual level of the supply voltage. Two modes of PWM regulation are
provided: The automatic tuning mode (AT) using current feedback (pwm_autoscale = 1, pwm_autograd
= 1) and a feed forward velocity-controlled mode (pwm_autoscale = 0). The feed forward velocitycontrolled mode will not react to a change of the supply voltage or to events like a motor stall, but it
provides very stable amplitude. It does not use nor require any means of current measurement. This
is perfect when motor type and supply voltage are well known. Therefore, we recommend the
automatic mode, unless current regulation is not satisfying in the given operating conditions.
It is recommended to operate in automatic tuning mode.
Non-automatic mode (pwm_autoscale=0) should be considered only with well-known motor and
operating conditions. In this case, programming via the UART interface is required. The operating
parameters PWM_GRAD and PWM_OFS can be determined in automatic tuning mode initially.
Hint: In non-automatic mode the power supply current directly reflects mechanical load on the motor.
The StealthChop PWM frequency can be chosen in four steps in order to adapt the frequency divider
to the frequency of the clock source. A setting in the range of 20-50kHz is good for most applications.
It balances low current ripple and good higher velocity performance vs. dynamic power dissipation.
CHOICE OF PWM FREQUENCY FOR STEALTHCHOP
Clock frequency
fCLK
PWM_FREQ=%00
fPWM=2/1024 fCLK
18MHz
16MHz
12MHz (internal)
10MHz
8MHz
35.2kHz
31.3kHz
23.4kHz
19.5kHz
15.6kHz
PWM_FREQ=%01
fPWM=2/683 fCLK
(default)
52.7kHz
46.9kHz
35.1kHz
29.3kHz
23.4kHz
PWM_FREQ=%10
fPWM=2/512 fCLK
(OTP option)
70.3kHz
62.5kHz
46.9kHz
39.1kHz
31.2kHz
PWM_FREQ=%11
fPWM=2/410 fCLK
87.8kHz
78.0kHz
58.5kHz
48.8kHz
39.0kHz
Table 6.1 Choice of PWM frequency – green / light green: recommended
6.3 StealthChop Current Regulator
In StealthChop voltage PWM mode, the autoscaling function (pwm_autoscale = 1, pwm_autograd = 1)
regulates the motor current to the desired current setting. Automatic scaling is used as part of the
automatic tuning process (AT), and for subsequent tracking of changes within the motor parameters.
The driver measures the motor current during the chopper on time and uses a proportional regulator
to regulate PWM_SCALE_AUTO in order match the motor current to the target current. PWM_REG is the
proportionality coefficient for this regulator. Basically, the proportionality coefficient should be as
small as possible in order to get a stable and soft regulation behavior, but it must be large enough to
allow the driver to quickly react to changes caused by variation of the motor target current (e.g.
change of VREF). During initial tuning step AT#2, PWM_REG also compensates for the change of motor
velocity. Therefore, a high acceleration during AT#2 will require a higher setting of PWM_REG. With
careful selection of homing velocity and acceleration, a minimum setting of the regulation gradient
often is sufficient (PWM_REG=1). PWM_REG setting should be optimized for the fastest required
acceleration and deceleration ramp (compare Figure 6.3 and Figure 6.4). The quality of the setting
PWM_REG in phase AT#2 and the finished automatic tuning procedure (or non-automatic settings for
PWM_OFS and PWM_GRAD) can be examined when monitoring motor current during an acceleration
phase Figure 6.5.
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TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
38
Figure 6.3 Scope shot: good setting for PWM_REG
Figure 6.4 Scope shot: too small setting for PWM_REG during AT#2
Motor Current
PWM scale
Motor Velocity
PWM reaches max. amplitude
RMS current constant
(IRUN)
PW
M_
Nominal Current
(sine wave RMS)
Stand still
PWM scale
PWM_OFS_(AUTO) ok
ok
O)
UT
(_A
AD
GR
M_
PW
GR
(P
AD
W
M_
(_A
RE
UT
G
O)
du
ok
rin
g
AT
#2
ok
)
255
Current may drop due
to high velocity
IHOLD
PWM_OFS_(AUTO) ok
0
0
Figure 6.5 Successfully determined PWM_GRAD(_AUTO) and PWM_OFS(_AUTO)
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Time
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
39
Quick Start
For a quick start, see the Quick Configuration Guide in chapter 16.
6.3.1
Lower Current Limit
The StealthChop current regulator imposes a lower limit for motor current regulation. As the coil
current can be measured in the shunt resistor during chopper on phase only, a minimum chopper
duty cycle allowing coil current regulation is given by the blank time as set by TBL and by the
chopper frequency setting. Therefore, the motor specific minimum coil current in StealthChop
autoscaling mode rises with the supply voltage and with the chopper frequency. A lower blanking
time allows a lower current limit. It is important for the correct determination of PWM_OFS_AUTO,
that in AT#1 the run current set by the sense resistor, VREF and IRUN is well within the regulation
range. Lower currents (e.g. for standstill power down) are automatically realized based on
PWM_OFS_AUTO and PWM_GRAD_AUTO respectively based on PWM_OFS and PWM_GRAD with nonautomatic current scaling. The freewheeling option allows going to zero motor current.
Lower motor coil current limit for StealthChop2 automatic tuning:
𝐼𝐿𝑜𝑤𝑒𝑟 𝐿𝑖𝑚𝑖𝑡 = 𝑡𝐵𝐿𝐴𝑁𝐾 ∗ 𝑓𝑃𝑊𝑀 ∗
𝑉𝑀
𝑅𝐶𝑂𝐼𝐿
With VM the motor supply voltage and RCOIL the motor coil resistance.
ILower Limit can be treated as a thumb value for the minimum nominal IRUN motor current setting.
EXAMPLE:
A motor has a coil resistance of 5Ω, the supply voltage is 24V. With TBL=%01 and PWM_FREQ=%00,
tBLANK is 24 clock cycles, fPWM is 2/(1024 clock cycles):
𝐼𝐿𝑜𝑤𝑒𝑟 𝐿𝑖𝑚𝑖𝑡 = 24 𝑡𝐶𝐿𝐾 ∗
2
24𝑉
24 24𝑉
∗
=
∗
= 225𝑚𝐴
1024 𝑡𝐶𝐿𝐾 5Ω
512 5Ω
This means, the motor target current for automatic tuning must be 225mA or more, taking into
account all relevant settings. This lower current limit also applies for modification of the motor
current via the analog input VREF.
Attention
For automatic tuning, a lower coil current limit applies. The motor current in automatic tuning phase
AT#1 must exceed this lower limit. ILOWER LIMIT can be calculated or measured using a current probe.
Setting the motor run-current or hold-current below the lower current limit during operation by
modifying IRUN and IHOLD is possible after successful automatic tuning.
With StealthChop, ensure that IRUN is in the range 8 to 31. Set vsense to yield lower current setting!
The lower current limit also limits the capability of the driver to respond to changes of VREF.
6.4 Velocity Based Scaling
UART
Velocity based scaling scales the StealthChop amplitude based on the time between each two steps,
i.e. based on TSTEP, measured in clock cycles. This concept basically does not require a current
measurement, because no regulation loop is necessary. A pure velocity-based scaling is available via
UART programming, only, when setting pwm_autoscale = 0. The basic idea is to have a linear
approximation of the voltage required to drive the target current into the motor. The stepper motor
has a certain coil resistance and thus needs a certain voltage amplitude to yield a target current
www.trinamic.com
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
40
based on the basic formula I=U/R. With R being the coil resistance, U the supply voltage scaled by the
PWM value, the current I results. The initial value for PWM_AMPL can be calculated:
𝑃𝑊𝑀_𝐴𝑀𝑃𝐿 =
374 ∗ 𝑅𝐶𝑂𝐼𝐿 ∗ 𝐼𝐶𝑂𝐼𝐿
𝑉𝑀
With VM the motor supply voltage and ICOIL the target RMS current
The effective PWM voltage UPWM (1/SQRT(2) x peak value) results considering the 8 bit resolution and
248 sine wave peak for the actual PWM amplitude shown as PWM_SCALE:
𝑈𝑃𝑊𝑀 = 𝑉𝑀 ∗
𝑃𝑊𝑀_𝑆𝐶𝐴𝐿𝐸 248 1
𝑃𝑊𝑀_𝑆𝐶𝐴𝐿𝐸
∗
∗
= 𝑉𝑀 ∗
256
256 √2
374
With rising motor velocity, the motor generates an increasing back EMF voltage. The back EMF voltage
is proportional to the motor velocity. It reduces the PWM voltage effective at the coil resistance and
thus current decreases. The TMC2209 provides a second velocity dependent factor (PWM_GRAD) to
compensate for this. The overall effective PWM amplitude (PWM_SCALE_SUM) in this mode
automatically is calculated in dependence of the microstep frequency as:
𝑓𝑆𝑇𝐸𝑃
𝑓𝐶𝐿𝐾
With fSTEP being the microstep frequency for 256 microstep resolution equivalent
and fCLK the clock frequency supplied to the driver or the actual internal frequency
𝑃𝑊𝑀_𝑆𝐶𝐴𝐿𝐸_𝑆𝑈𝑀 = 𝑃𝑊𝑀_𝑂𝐹𝑆 + 𝑃𝑊𝑀_𝐺𝑅𝐴𝐷 ∗ 256 ∗
As a first approximation, the back EMF subtracts from the supply voltage and thus the effective current
amplitude decreases. This way, a first approximation for PWM_GRAD setting can be calculated:
𝑃𝑊𝑀_𝐺𝑅𝐴𝐷 = 𝐶𝐵𝐸𝑀𝐹 [
𝑉
𝑓𝐶𝐿𝐾 ∗ 1.46
] ∗ 2𝜋 ∗
𝑟𝑎𝑑
𝑉𝑀 ∗ 𝑀𝑆𝑃𝑅
𝑠
CBEMF is the back EMF constant of the motor in Volts per radian/second.
MSPR is the number of microsteps per rotation, e.g. 51200 = 256µsteps multiplied by 200 fullsteps for
a 1.8° motor.
Motor current
PWM scaling
(PWM_SCALE_SUM)
255
PWM reaches
max. amplitude
Constant motor
RMS current
Nominal current
(e.g. sine wave RMS)
M_
PW
AD
GR
Cur
r
(de ent dr
p en
ops
mo
d
tor s on
loa
d)
PWM_OFS
0
0
VPWMMAX
Figure 6.6 Velocity based PWM scaling (pwm_autoscale=0)
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Velocity
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
41
Hint
The values for PWM_OFS and PWM_GRAD can easily be optimized by tracing the motor current with a
current probe on the oscilloscope. Alternatively, automatic tuning determines these values and they
can be read out from PWM_OFS_AUTO and PWM_GRAD_AUTO.
UNDERSTANDING THE BACK EMF CONSTANT OF A MOTOR
The back EMF constant is the voltage a motor generates when turned with a certain velocity. Often
motor datasheets do not specify this value, as it can be deducted from motor torque and coil current
rating. Within SI units, the numeric value of the back EMF constant CBEMF has the same numeric value
as the numeric value of the torque constant. For example, a motor with a torque constant of 1 Nm/A
would have a CBEMF of 1V/rad/s. Turning such a motor with 1 rps (1 rps = 1 revolution per second =
6.28 rad/s) generates a back EMF voltage of 6.28V. Thus, the back EMF constant can be calculated as:
𝐶𝐵𝐸𝑀𝐹 [
𝑉
𝐻𝑜𝑙𝑑𝑖𝑛𝑔𝑇𝑜𝑟𝑞𝑢𝑒[𝑁𝑚]
]=
𝑟𝑎𝑑/𝑠
2 ∗ 𝐼𝐶𝑂𝐼𝐿𝑁𝑂𝑀 [𝐴]
ICOILNOM is the motor’s rated phase current for the specified holding torque
HoldingTorque is the motor specific holding torque, i.e. the torque reached at ICOILNOM on both coils.
The torque unit is [Nm] where 1Nm = 100Ncm = 1000mNm.
The voltage is valid as RMS voltage per coil, thus the nominal current is multiplied by 2 in this
formula, since the nominal current assumes a full step position, with two coils operating.
6.5 Combine StealthChop and SpreadCycle
UART
OTP
For applications requiring high velocity motion, SpreadCycle may bring more stable operation in the
upper velocity range. To combine no-noise operation with highest dynamic performance, the TMC2209
allows combining StealthChop and SpreadCycle based on a velocity threshold (Figure 6.7). A velocity
threshold (TPWMTHRS) can be preprogrammed to OTP to support this mode even in standalone
operation. With this, StealthChop is only active at low velocities.
Chopper mode
stealthChop
spreadCycle
option
option
motor going to standby
motor in standby
motor stand still
Running low speed
Running high speed
Running low speed
TSTEP < TPWMTHRS*16/16
TSTEP > TPWMTHRS
motor in standby
v
0
t
RMS current
TRINAMIC, B. Dwersteg, 14.3.14
Figure 6.7 TPWMTHRS for optional switching to SpreadCycle
www.trinamic.com
dI * IHOLDDELAY
VACTUAL
~1/TSTEP
TPOWERDOWN
current
I_RUN
I_HOLD
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
42
As a first step, both chopper principles should be parameterized and optimized individually
(SpreadCycle settings may be programmed to OTP memory). In a next step, a transfer velocity has to
be fixed. For example, StealthChop operation is used for precise low speed positioning, while
SpreadCycle shall be used for highly dynamic motion. TPWMTHRS determines the transition velocity.
Read out TSTEP when moving at the desired velocity and program the resulting value to TPWMTHRS.
Use a low transfer velocity to avoid a jerk at the switching point.
A jerk occurs when switching at higher velocities, because the back-EMF of the motor (which rises
with the velocity) causes a phase shift of up to 90° between motor voltage and motor current. So
when switching at higher velocities between voltage PWM and current PWM mode, this jerk will occur
with increased intensity. A high jerk may even produce a temporary overcurrent condition (depending
on the motor coil resistance). At low velocities (e.g. 1 to a few 10 RPM), it can be completely
neglected for most motors. Therefore, consider the switching jerk when choosing TPWMTHRS. Set
TPWMTHRS zero if you want to work with StealthChop only.
When enabling the StealthChop mode the first time using automatic current regulation, the motor
must be at stand still in order to allow a proper current regulation. When the drive switches to
StealthChop at a higher velocity, StealthChop logic stores the last current regulation setting until the
motor returns to a lower velocity again. This way, the regulation has a known starting point when
returning to a lower velocity, where StealthChop becomes re-enabled. Therefore, neither the velocity
threshold nor the supply voltage must be considerably changed during the phase while the chopper
is switched to a different mode, because otherwise the motor might lose steps or the instantaneous
current might be too high or too low.
A motor stall or a sudden change in the motor velocity may lead to the driver detecting a short
circuit or to a state of automatic current regulation, from which it cannot recover. Clear the error flags
and restart the motor from zero velocity to recover from this situation.
Hint
Start the motor from standstill when switching on StealthChop the first time and keep it stopped for
at least 128 chopper periods to allow StealthChop to do initial standstill current control.
6.6 Flags in StealthChop
UART
As StealthChop uses voltage mode driving, status flags based on current measurement respond
slower, respectively the driver reacts delayed to sudden changes of back EMF, like on a motor stall.
Attention
A motor stall, or abrupt stop of the motion during operation in StealthChop can trigger an
overcurrent condition. Depending on the previous motor velocity, and on the coil resistance of the
motor, it significantly increases motor current for a time of several 10ms. With low velocities, where
the back EMF is just a fraction of the supply voltage, there is no danger of triggering the short
detection. When homing using StallGuard4 to stop the motor upon stall, this is basically avoided.
6.6.1
Open Load Flags
In StealthChop mode, status information is different from the cycle-by-cycle regulated SpreadCycle
mode. OLA and OLB show if the current regulation sees that the nominal current can be reached on
both coils.
-
A flickering OLA or OLB can result from asymmetries in the sense resistors or in the motor
coils.
An interrupted motor coil leads to a continuously active open load flag for the coil.
One or both flags are active, if the current regulation did not succeed in scaling up to the full
target current within the last few fullsteps (because no motor is attached or a high velocity
exceeds the PWM limit).
If desired, do an on-demand open load test using the SpreadCycle chopper, as it delivers the safest
result. With StealthChop, PWM_SCALE_SUM can be checked to detect the correct coil resistance.
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TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
6.6.2
43
PWM_SCALE_SUM Informs about the Motor State
Information about the motor state is available with automatic scaling by reading out
PWM_SCALE_SUM. As this parameter reflects the actual voltage required to drive the target current into
the motor, it depends on several factors: motor load, coil resistance, supply voltage, and current
setting. Therefore, an evaluation of the PWM_SCALE_SUM value allows checking the motor operation
point. When reaching the limit (255), the current regulator cannot sustain the full motor current, e.g.
due to a drop in supply volage.
6.7 Freewheeling and Passive Braking
UART
StealthChop provides different options for motor standstill. These options can be enabled by setting
the standstill current IHOLD to zero and choosing the desired option using the FREEWHEEL setting.
The desired option becomes enabled after a time period specified by TPOWERDOWN and
IHOLD_DELAY. Current regulation becomes frozen once the motor target current is at zero current in
order to ensure a quick startup. With the freewheeling options, both freewheeling and passive
braking can be realized. Passive braking is an effective eddy current motor braking, which consumes a
minimum of energy, because no active current is driven into the coils. However, passive braking will
allow slow turning of the motor when a continuous torque is applied.
Hint
Operate the motor within your application when exploring StealthChop. Motor performance often is
better with a mechanical load, because it prevents the motor from stalling due mechanical oscillations
which can occur without load.
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TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
44
PARAMETERS RELATED TO STEALTHCHOP
Parameter
en_spread_
cycle
TPWMTHRS
PWM_LIM
pwm_
autoscale
pwm_
autograd
Description
General disable for use of StealthChop (register
GCONF). The input SPREAD is XORed to this flag.
Specifies the upper velocity for operation in
StealthChop. Entry the TSTEP reading (time
between two microsteps) when operating at the
desired threshold velocity.
Limiting value for limiting the current jerk when
switching from SpreadCycle to StealthChop.
Reduce the value to yield a lower current jerk.
Enable automatic current scaling using current
measurement or use forward controlled velocity
based mode.
Enable automatic tuning of PWM_GRAD_AUTO
Setting
1
0
0…
1048575
Comment
Do not use StealthChop
StealthChop enabled
StealthChop is disabled if
TSTEP falls TPWMTHRS
0 … 15
Upper four bits of 8 bit
amplitude limit
(Default=12)
Forward controlled mode
Automatic scaling with
current regulator
disable, use PWM_GRAD
from register instead
enable
fPWM=2/1024 fCLK
fPWM=2/683 fCLK
fPWM=2/512 fCLK
fPWM=2/410 fCLK
Results in 0.5 to 7.5 steps
for PWM_SCALE_AUTO
regulator per fullstep
PWM_OFS=0 disables
linear current scaling
based on current setting
Reset value can be preprogrammed by OTP
0
1
0
1
0
1
2
3
PWM_REG
User defined PWM amplitude (gradient) for 1 … 15
velocity based scaling or regulation loop gradient
when pwm_autoscale=1.
PWM_OFS
User defined PWM amplitude (offset) for velocity 0 … 255
based scaling and initialization value for automatic
tuning of PWM_OFFS_AUTO.
PWM_GRAD User defined PWM amplitude (gradient) for 0 … 255
velocity based scaling and initialization value for
automatic tuning of PWM_GRAD_AUTO.
FREEWHEEL Stand still option when motor current setting is 0
zero (I_HOLD=0). Only available with StealthChop 1
enabled. The freewheeling option makes the 2
motor easy movable, while both coil short options 3
realize a passive brake.
PWM_SCALE Read back of the actual StealthChop voltage PWM -255 …
_AUTO
scaling correction as determined by the current 255
regulator. Should regulate to a value close to 0
during tuning procedure.
PWM_GRAD Allow monitoring of the automatic tuning and 0 … 255
_AUTO
determination of initial values for PWM_OFS and
PWM_OFS
PWM_GRAD.
_AUTO
TOFF
General enable for the motor driver, the actual 0
value does not influence StealthChop
1 … 15
TBL
Comparator blank time. This time needs to safely 0
cover the switching event and the duration of the 1
ringing on the sense resistor. Choose a setting of 2
1 or 2 for typical applications. For higher 3
capacitive loads, 3 may be required. Lower
settings allow StealthChop to regulate down to
lower coil current values.
PWM_FREQ
PWM frequency selection. Use the lowest setting
giving good results. The frequency measured at
each of the chopper outputs is half of the
effective chopper frequency fPWM.
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Normal operation
Freewheeling
Coil short via LS drivers
Coil short cia HS drivers
(read only) Scaling value
becomes frozen when
operating in SpreadCycle
(read only)
Driver off
Driver enabled
16 tCLK
24 tCLK
32 tCLK
40 tCLK
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
7
45
SpreadCycle Chopper
While StealthChop is a voltage mode PWM controlled chopper, SpreadCycle is a cycle-by-cycle current
control. Therefore, it can react extremely fast to changes in motor velocity or motor load. SpreadCycle
will give better performance in medium to high velocity range for motors and applications which
tend to resonance. The currents through both motor coils are controlled using choppers. The choppers
work independently of each other. In Figure 7.1 the different chopper phases are shown.
+VM
+VM
+VM
ICOIL
ICOIL
ICOIL
RSENSE
On Phase:
current flows in
direction of target
current
RSENSE
Fast Decay Phase:
current flows in
opposite direction
of target current
RSENSE
Slow Decay Phase:
current re-circulation
Figure 7.1 Chopper phases
Although the current could be regulated using only on phases and fast decay phases, insertion of the
slow decay phase is important to reduce electrical losses and current ripple in the motor. The
duration of the slow decay phase is specified in a control parameter and sets an upper limit on the
chopper frequency. The current comparator can measure coil current during phases when the current
flows through the sense resistor, but not during the slow decay phase, so the slow decay phase is
terminated by a timer. The on phase is terminated by the comparator when the current through the
coil reaches the target current. The fast decay phase may be terminated by either the comparator or
another timer.
When the coil current is switched, spikes at the sense resistors occur due to charging and discharging
parasitic capacitances. During this time, typically one or two microseconds, the current cannot be
measured. Blanking is the time when the input to the comparator is masked to block these spikes.
The SpreadCycle chopper mode cycles through four phases: on, slow decay, fast decay, and a second
slow decay.
The chopper frequency is an important parameter for a chopped motor driver. A too low frequency
might generate audible noise. A higher frequency reduces current ripple in the motor, but with a too
high frequency magnetic losses may rise. Also power dissipation in the driver rises with increasing
frequency due to the increased influence of switching slopes causing dynamic dissipation. Therefore, a
compromise needs to be found. Most motors are optimally working in a frequency range of 16 kHz to
30 kHz. The chopper frequency is influenced by a number of parameter settings as well as by the
motor inductivity and supply voltage.
Hint
A chopper frequency in the range of 16 kHz to 30 kHz gives a good result for most motors when
using SpreadCycle. A higher frequency leads to increased switching losses.
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TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
7.1 SpreadCycle Settings
46
UART
OTP
The SpreadCycle (patented) chopper algorithm is a precise and simple to use chopper mode which
automatically determines the optimum length for the fast-decay phase. The SpreadCycle will provide
superior microstepping quality even with default settings. Several parameters are available to
optimize the chopper to the application.
Each chopper cycle is comprised of an on phase, a slow decay phase, a fast decay phase and a
second slow decay phase (see Figure 7.3). The two slow decay phases and the two blank times per
chopper cycle put an upper limit to the chopper frequency. The slow decay phases typically make up
for about 30%-70% of the chopper cycle in standstill and are important for low motor and driver
power dissipation.
Calculation of a starting value for the slow decay time TOFF:
EXAMPLE:
Target Chopper frequency: 25kHz.
Assumption: Two slow decay cycles make up for 50% of overall chopper cycle time
𝑡𝑂𝐹𝐹 =
For the TOFF setting this means:
1
50 1
∗
∗ = 10µ𝑠
25𝑘𝐻𝑧 100 2
𝑇𝑂𝐹𝐹 = (𝑡𝑂𝐹𝐹 ∗ 𝑓𝐶𝐿𝐾 − 24)/32
With 12 MHz clock this gives a setting of TOFF=3.0, i.e. 3.
With 16 MHz clock this gives a setting of TOFF=4.25, i.e. 4 or 5.
The hysteresis start setting forces the driver to introduce a minimum amount of current ripple into
the motor coils. The current ripple must be higher than the current ripple which is caused by resistive
losses in the motor in order to give best microstepping results. This will allow the chopper to
precisely regulate the current both for rising and for falling target current. The time required to
introduce the current ripple into the motor coil also reduces the chopper frequency. Therefore, a
higher hysteresis setting will lead to a lower chopper frequency. The motor inductance limits the
ability of the chopper to follow a changing motor current. Further the duration of the on phase and
the fast decay must be longer than the blanking time, because the current comparator is disabled
during blanking.
It is easiest to find the best setting by starting from a low hysteresis setting (e.g. HSTRT=0, HEND=0)
and increasing HSTRT, until the motor runs smoothly at low velocity settings. This can best be
checked when measuring the motor current either with a current probe or by probing the sense
resistor voltages (see Figure 7.2). Checking the sine wave shape near zero transition will show a small
ledge between both half waves in case the hysteresis setting is too small. At medium velocities (i.e.
100 to 400 fullsteps per second), a too low hysteresis setting will lead to increased humming and
vibration of the motor.
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TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
47
Figure 7.2 No ledges in current wave with sufficient hysteresis (magenta: current A, yellow &
blue: sense resistor voltages A and B)
A too high hysteresis setting will lead to reduced chopper frequency and increased chopper noise but
will not yield any benefit for the wave shape.
Quick Start
For a quick start, see the Quick Configuration Guide in chapter 16.
For detail procedure see Application Note AN001 - Parameterization of SpreadCycle
As experiments show, the setting is quite independent of the motor, because higher current motors
typically also have a lower coil resistance. Therefore, choosing a low to medium default value for the
hysteresis (for example, effective hysteresis = 4) normally fits most applications. The setting can be
optimized by experimenting with the motor: A too low setting will result in reduced microstep
accuracy, while a too high setting will lead to more chopper noise and motor power dissipation.
When measuring the sense resistor voltage in motor standstill at a medium coil current with an
oscilloscope, a too low setting shows a fast decay phase not longer than the blanking time. When
the fast decay time becomes slightly longer than the blanking time, the setting is optimum. You can
reduce the off-time setting, if this is hard to reach.
The hysteresis principle could in some cases lead to the chopper frequency becoming too low, e.g.
when the coil resistance is high when compared to the supply voltage. This is avoided by splitting
the hysteresis setting into a start setting (HSTRT+HEND) and an end setting (HEND). An automatic
hysteresis decrementer (HDEC) interpolates between both settings, by decrementing the hysteresis
value stepwise each 16 system clocks. At the beginning of each chopper cycle, the hysteresis begins
with a value which is the sum of the start and the end values (HSTRT+HEND), and decrements during
the cycle, until either the chopper cycle ends or the hysteresis end value (HEND) is reached. This way,
the chopper frequency is stabilized at high amplitudes and low supply voltage situations, if the
frequency gets too low. This avoids the frequency reaching the audible range.
Hint
Highest motor velocities sometimes benefit from setting TOFF to 1 or 2 and a short TBL of 1 or 0.
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TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
I
target current + hysteresis start
48
HDEC
target current + hysteresis end
target current
target current - hysteresis end
target current - hysteresis start
on
sd
fd
sd
t
Figure 7.3 SpreadCycle chopper scheme showing coil current during a chopper cycle
These parameters control SpreadCycle mode:
Parameter
TOFF
TBL
HSTRT
HEND
Description
Sets the slow decay time (off time). This setting also
limits the maximum chopper frequency.
For operation with StealthChop, this parameter is not
used, but it is required to enable the motor. In case
of operation with StealthChop only, any setting is
OK.
Setting this parameter to zero completely disables all
driver transistors and the motor can free-wheel.
Comparator blank time. This time needs to safely
cover the switching event and the duration of the
ringing on the sense resistor. For most
applications, a setting of 1 or 2 is good. For highly
capacitive loads, a setting of 2 or 3 will be
required.
Hysteresis start setting. This value is an offset from
the hysteresis end value HEND.
Setting
0
1…15
Comment
chopper off
off time setting
NCLK= 24 + 32*TOFF
(1 will work with minimum
blank time of 24 clocks)
0
16 tCLK
1
24 tCLK
2
32 tCLK
3
40 tCLK
0…7
HSTRT=1…8
Hysteresis end setting. Sets the hysteresis end value 0…2
after a number of decrements. The sum HSTRT+HEND 3
must be ≤16. At a current setting of max. 30
4…15
(amplitude reduced to 240), the sum is not limited.
This value adds to HEND.
-3…-1: negative HEND
0: zero HEND
1…12: positive HEND
Even at HSTRT=0 and HEND=0, the TMC2209 sets a minimum hysteresis via analog circuitry.
EXAMPLE:
A hysteresis of 4 has been chosen. You might decide to not use hysteresis decrement. In this case
set:
HEND=6
HSTRT=0
(sets an effective end value of 6-3=3)
(sets minimum hysteresis, i.e. 1: 3+1=4)
In order to take advantage of the variable hysteresis, we can set most of the value to the HSTRT, i.e.
4, and the remaining 1 to hysteresis end. The resulting configuration register values are as follows:
HEND=0
HSTRT=6
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(sets an effective end value of -3)
(sets an effective start value of hysteresis end +7: 7-3=4)
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
8
49
Selecting Sense Resistors
Set the desired maximum motor current by selecting an appropriate value for the sense resistor. The
following table shows the RMS current values which can be reached using standard resistors and
motor types fitting without additional motor current scaling.
CHOICE OF RSENSE AND RESULTING MAX. MOTOR CURRENT
RSENSE [Ω]
RMS current [A]
Fitting motor type
VREF=2.5V (or open),
(examples)
IRUN=31,
vsense=0 (standard)
1.00
0.23
0.82
0.27
0.75
0.30
300mA motor
0.68
0.33
400mA motor
0.50
0.44
470m
0.47
500mA motor
390m
0.56
600mA motor
330m
0.66
700mA motor
270m
0.79
800mA motor
220m
0.96
1A motor
180m
1.15
1.2A motor
150m
1.35
1.5A motor
120m
1.64
1.7A motor
100m
1.92
2A motor
75m
2.4*)
*) Value exceeds upper current rating, scaling down required, e.g. by reduced VREF.
Sense resistors should be carefully selected. The full motor current flows through the sense resistors.
Due to chopper operation the sense resistors see pulsed current from the MOSFET bridges. Therefore,
a low-inductance type such as film or composition resistors is required to prevent voltage spikes
causing ringing on the sense voltage inputs leading to unstable measurement results. Also, a lowinductance, low-resistance PCB layout is essential. Any common GND path for the two sense resistors
must be avoided, because this would lead to coupling between the two current sense signals. A
massive ground plane is best. Please also refer to layout considerations in chapter 21.
The sense resistor needs to be able to conduct the peak motor coil current in motor standstill
conditions, unless standby power is reduced. Under normal conditions, the sense resistor conducts
less than the coil RMS current, because no current flows through the sense resistor during the slow
decay phases. A 0.5W type is sufficient for most applications up to 1.2A RMS current.
Attention
Be sure to use a symmetrical sense resistor layout and short and straight sense resistor traces of
identical length. Well matching sense resistors ensure best performance.
A compact layout with massive ground plane is best to avoid parasitic resistance effects.
Check the resulting motor current in a practical application and with the desired motor.
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TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
9
50
Motor Current Control
The basic motor current is set by the resistance of the sense resistors. Several possibilities allow
scaling down motor current, e.g. to adapt for different motors, or to reduce motor current in standstill
or low load situations.
METHODS FOR SCALING MOTOR CURRENT
Method
Pin VREF
voltage
(chapter 9.1)
Parameters
VREF input scales
IRUN and IHOLD.
Can be disabled by
GCONF.i_scale_analog
Range
2.5V: 100% …
0.5V: 20%
>2.5V or open: 100%
20kHz
0-2.4V for
current scaling
22k
1µ
R1+R2»10K
Analog Scaling
Fixed resistor divider to set current scale
(use external reference for enhanced precision)
Analog Scaling
Precision current scaler
Figure 9.1 Scaling the motor current using the analog input
www.trinamic.com
VREF
BC847
VREF
100k
VREF
Optional
digital
control
Analog Scaling
Simple PWM based current scaler
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
53
10 Internal Sense Resistors
UART
OTP
The TMC2209 provides the option to eliminate external sense resistors. In this mode the external
sense resistors become omitted (shorted) and the internal on-resistance of the power MOSFETs is
used for current measurement (see chapter 3.2). As MOSFETs are both, temperature dependent and
subject to production stray, a tiny external resistor connected from +5VOUT to VREF provides a precise
absolute current reference. This resistor converts the 5V voltage into a reference current. Be sure to
directly attach BRA and BRB pins to GND in this mode near the IC package. The mode is enabled by
setting internal_Rsense in GCONF (OTP option).
COMPARING INTERNAL SENSE RESISTORS VS. SENSE RESISTORS
Item
Ease of use
Cost
Current precision
Current Range
Recommended
Recommended
chopper
Internal Sense Resistors
Need to set OTP parameter
before motor enable
(+) Save cost for sense resistors
Slightly reduced
200mA RMS to 1.4A RMS
External Sense Resistors
(+) Default
StealthChop or SpreadCycle
SpreadCycle shows slightly more
distortion at >1.4A RMS
StealthChop or SpreadCycle
(+) Good
50mA to 2A RMS
While the RDSon based measurements bring benefits concerning cost and size of the driver, it gives
slightly less precise coil current regulation when compared to external sense resistors. The internal
sense resistors have a certain temperature dependence, which is automatically compensated by the
driver IC. However, for high current motors, a temperature gradient between the ICs internal sense
resistors and the compensation circuit will lead to an initial current overshoot of some 10% during
driver IC heat up. While this phenomenon shows for roughly a second, it might even be beneficial to
enable increased torque during initial motor acceleration.
PRINCIPLE OF OPERATION
A reference current into the VREF pin is used as reference for the motor current. In order to realize a
certain current, a single resistor (RREF) can be connected between 5VOUT and VREF (pls. refer the table
for the choice of the resistor). VREF input resistance is about 0.45kOhm. The resulting current into
VREF is amplified 3000 times. Thus, a current of 0.33mA yields a motor current of 1.0A peak, or 0.7A
RMS. For calculation of the reference resistor, the internal resistance of VREF needs to be considered
additionally.
CHOICE OF RREF FOR OPERATION WITHOUT SENSE RESISTORS
RREF [Ω]
6k2
6k8
7k5
8k2
9k1
10k
12k
15k
18k
22k
27k
33k
Peak current [A]
(CS=31, vsense=0)
2.26
1.92
1.76
1.63
1.49
1.36
1.15
0.94
0.79
0.65
0.60
0.54
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RMS current [A]
(CS=31, vsense=0)
1.59
1.35
1.24
1.15
1.05
0.96
0.81
0.66
0.55
0.45
0.42
0.38
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
54
vsense=1 allows a lower peak current setting of about 55% of the value yielded with vsense=0 (as
specified by VSRTH / VSRTL).
In RDSon measurement mode, connect the BRA and BRB pins to GND using the shortest possible path
(i.e. shortest possible PCB path). RDSon based measurement gives best results when combined with
StealthChop. When using SpreadCycle with RDSon based current measurement, slightly asymmetric
current measurement for positive currents (on phase) and negative currents (fast decay phase) may
result in chopper noise. This especially occurs at high die temperature and increased motor current.
Note
The absolute current levels achieved with RDSon based current sensing may depend on PCB layout
exactly like with external sense resistors, because trace resistance on BR pins will add to the effective
sense resistance. Therefore, we recommend to measure and calibrate the current setting within the
application.
Thumb rule
RDSon based current sensing works best for motors with up to 1.4A RMS current. The best results are
yielded with StealthChop operation in combination with RDSon based current sensing.
For most precise current control and for best results with SpreadCycle, it is recommended to use
external 1% sense resistors rather than RDSon based current control.
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TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
55
11 StallGuard4 Load Measurement
UART
StallGuard4 provides an accurate measurement of the load on the motor. It is developed for operation
in conjunction with StealthChop. StallGuard can be used for stall detection as well as other uses at
loads below those which stall the motor, such as CoolStep load-adaptive current reduction. The
StallGuard4 measurement value changes linearly over a wide range of load, velocity, and current
settings, as shown in Figure 11.1. When approaching maximum motor load, the value goes down to a
motor-specific lower value. This corresponds to a load angle of 90° between the magnetic field of the
coils and magnets in the rotor. This also is the most energy-efficient point of operation for the motor.
500
StallGuard4 reading
SG_RESULT
450
Start value depends
on motor, velocity
and operating current
400
350
SG_RESULT reaches compare
value and indicates danger of
stall. This point is set by
stallGuard threshold value
SGTHRS.
300
100% load value depends on
motor, operating current and
velocity
250
200
Stall detection
150
threshold SGTHRS*2
high 100
Stall Output
low 50
0
Motor stalls above this point.
Load angle exceeds 90° and
available torque sinks.
10
20
30
40
50
60
70
80
90
100
motor load
(% max. torque)
Figure 11.1 Function principle of StallGuard4
Parameter
SGTHRS
Status word
SG_RESULT
Description
This value controls the StallGuard4 threshold
level for stall detection. It compensates for
motor specific characteristics and controls
sensitivity. A higher value gives a higher
sensitivity. A higher value makes StallGuard4
more sensitive and requires less torque to
indicate a stall.
Description
This is the StallGuard4 result. A higher reading
indicates less mechanical load. A lower reading
indicates a higher load and thus a higher load
angle.
Setting
0… 255
Comment
The double of this value is
compared to SG_RESULT.
The stall output becomes
active if SG_RESULT fall
below this value.
Range
0… 510
Comment
Low value: highest load
High value: high load
In order to use StallGuard4, check the sensitivity of the motor at border conditions.
11.1 StallGuard4 vs. StallGuard2
StallGuard4 is optimized for operation with StealthChop, its predecessor StallGuard2 works with
SpreadCycle. The function is similar: Both deliver a load value, going from a high value at low load, to
a low value at high load. While StallGuard2 becomes tuned to show a “0”-reading for stall detection,
StallGuard4 uses a comparison-value to trigger stall detection, rather than shifting SG_RESULT itself.
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TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
56
11.2 Tuning StallGuard4
The StallGuard4 value SG_RESULT is affected by motor-specific characteristics and application-specific
demands on load, coil current, and velocity. Therefore, the easiest way to tune the StallGuard4
threshold SGTHRS for a specific motor type and operating conditions is interactive tuning in the actual
application.
INITIAL PROCEDURE FOR TUNING STALLGUARD SGTHRS
1.
2.
3.
4.
Operate the motor at the normal operation velocity for your application and monitor SG_RESULT.
Apply slowly increasing mechanical load to the motor. Check the lowest value of SG_RESULT
before the motor stalls. Use this value as starting value for SGTHRS (apply half of the value).
Now monitor the StallGuard output signal via DIAG output (configure properly, also set
TCOOLTHRS to match the lower velocity limit for operation) and stop the motor when a pulse is
seen on the respective output. Make sure, that the motor is safely stopped whenever it is stalled.
Increase SGTHRS if the motor becomes stopped before a stall occurs.
The optimum setting is reached when a stall is safely detected and leads to a pulse at DIAG in
the moment where the stall occurs. SGTHRS in most cases can be tuned for a certain motion
velocity or a velocity range. Make sure, that the setting works reliable in a certain range (e.g. 80%
to 120% of desired velocity) and also under extreme motor conditions (lowest and highest
applicable temperature).
DIAG is pulsed by StallGuard, when SG_RESULT falls below SGTHRS. It is only enabled in StealthChop
mode, and when TCOOLTHRS ≥ TSTEP > TPWMTHRS
The external motion controller should react to a single pulse by stopping the motor if desired. Set
TCOOLTHRS to match the lower velocity threshold where StallGuard delivers a good result.
SG_RESULT measurement has a high resolution, and there are a few ways to enhance its accuracy, as
described in the following sections.
11.3 StallGuard4 Update Rate
The StallGuard4 measurement value SG_RESULT is updated with each full step of the motor. This is
enough to safely detect a stall, because a stall always means the loss of four full steps.
11.4 Detecting a Motor Stall
To safely detect a motor stall, the stall threshold must be determined using a specific SGTHRS setting
and a specific motor velocity or velocity range. Further, the motor current setting has a certain
influence and should not be modified, once optimum values are determined. Therefore, the maximum
load needs to be determined the motor can drive without stalling. At the same time, monitor
SG_RESULT at this load. The stall threshold should be a value safely within the operating limits, to
allow for parameter stray. More refined evaluation may also react to a change of SG_RESULT rather
than comparing to a fixed threshold. This will rule out certain effects which influence the absolute
value.
11.5 Limits of StallGuard4 Operation
StallGuard4 does not operate reliably at extreme motor velocities: Very low motor velocities (for many
motors, less than one revolution per second) generate a low back EMF and make the measurement
unstable and dependent on environment conditions (temperature, etc.). Other conditions will also lead
to a poor response of the measurement value SG_RESULT to the motor load. Very high motor
velocities, in which the full sinusoidal current is not driven into the motor coils also leads to poor
response. These velocities are typically characterized by the motor back EMF exceeding the supply
voltage.
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TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
57
12 CoolStep Operation
UART
CoolStep is an automatic smart energy optimization for stepper motors based on the motor
mechanical load, making them “green”.
12.1 User Benefits
Energy efficiency
Motor generates less heat
Less cooling infrastructure
Cheaper motor
–
–
–
–
consumption decreased up to 75%
improved mechanical precision
for motor and driver
does the job!
CoolStep allows substantial energy savings, especially for motors which see varying loads or operate
at a high duty cycle. Because a stepper motor application needs to work with a torque reserve of 30%
to 50%, even a constant-load application allows significant energy savings because CoolStep
automatically enables torque reserve when required. Reducing power consumption keeps the system
cooler, increases motor life, and allows reducing cost in the power supply and cooling components.
Reducing motor current by half results in reducing power by a factor of four.
12.2 Setting up for CoolStep
CoolStep is controlled by several parameters, but two are critical for understanding how it works:
Parameter
Description
SEMIN
4-bit unsigned integer that sets a lower threshold. 0
If SG_RESULT goes below this threshold, CoolStep 1…15
increases the current to both coils. The 4-bit
SEMIN value is scaled by 32 to cover the lower
half of the range of the 10-bit SG value. (The
name of this parameter is derived from
SmartEnergy, which is an earlier name for
CoolStep.)
4-bit unsigned integer that controls an upper 0…15
threshold. If SG is sampled equal to or above this
threshold enough times, CoolStep decreases the
current to both coils. The upper threshold is
(SEMIN + SEMAX + 1)*32.
SEMAX
Figure
-
Range
Comment
disable CoolStep
threshold is SEMIN*32
Once SGTHRS has been
determined, use
1/16*SGTHRS+1
as a starting point for
SEMIN.
threshold is
(SEMIN+SEMAX+1)*32
0 to 2 recommended
12.1 shows the operating regions of CoolStep:
The black line represents the SG_RESULT measurement value.
The blue line represents the mechanical load applied to the motor.
The red line represents the current into the motor coils.
When the load increases, SG_RESULT falls below SEMIN, and CoolStep increases the current. When the
load decreases, SG_RESULT rises above (SEMIN + SEMAX + 1) * 32, and the current is reduced.
www.trinamic.com
stallGuard2
reading
mechanical load
58
motor current
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
current setting I_RUN
(upper limit)
motor current reduction area
SEMAX+SEMIN+1
SEMIN
½ or ¼ I_RUN
(lower limit)
motor current increment area
0=maximum load
load angle optimized
Zeit
slow current reduction due
to reduced motor load
load
angle
optimized
current increment due to
increased load
stall possible
load angle optimized
Figure 12.1 CoolStep adapts motor current to the load
Five more parameters control CoolStep and one status value is returned:
Parameter
SEUP
SEDN
SEIMIN
TCOOLTHRS
TPWMTHRS
Status
word
CSACTUAL
Description
Range
Sets the current increment step. The current 0…3
becomes incremented for each measured
StallGuard2 value below the lower threshold.
Sets the number of StallGuard2 readings above 0…3
the upper threshold necessary for each current
decrement of the motor current.
Sets the lower motor current limit for CoolStep
operation by scaling the IRUN current setting.
Operate well above the minimum motor current
as determined for StealthChop current regulation.
Lower velocity threshold for switching on
CoolStep and stall output. Below this velocity
CoolStep becomes disabled (not used in STEP/DIR
mode). Adapt to the lower limit of the velocity
range where StallGuard2 gives a stable result.
Upper velocity threshold value for CoolStep and
stop on stall. Above this velocity the driver
switches to SpreadCycle. This also disables
CoolStep and StallGuard.
Description
0
1
number of StallGuard2
measurements per
decrement:
32, 8, 2, 1
0: 1/2 of IRUN
1: 1/4 of IRUN
1…
2^20-1
Specifies lower CoolStep
velocity by comparing
the threshold value to
TSTEP
1…
2^20-1
This setting typically is
used during chopper
mode configuration,
only.
Comment
Range
This status value provides the actual motor 0…31
current scale as controlled by CoolStep. The value
goes up to the IRUN value and down to the
portion of IRUN as specified by SEIMIN.
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Comment
step width is
1, 2, 4, 8
1/32, 2/32, … 32/32
TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26)
59
12.3 Tuning CoolStep
CoolStep uses SG_RESULT to operate the motor near the optimum load angle of +90°. The basic
setting to be tuned is SEMIN. Set SEMIN to a value which safely activates CoolStep current increment
before the motor stalls. In case SGTHRS has been tuned before, a lower starting value is
SEMIN = 1+SGTHRS/16.
The current increment speed is specified in SEUP, and the current decrement speed is specified in
SEDN. They can be tuned separately because they are triggered by different events that may need
different responses. The encodings for these parameters allow the coil currents to be increased much
more quickly than decreased, because crossing the lower threshold is a more serious event that may
require a faster response. If the response is too slow, the motor may stall. In contrast, a slow
response to crossing the upper threshold does not risk anything more serious than missing an
opportunity to save power.
CoolStep operates between limits controlled by the current scale parameter IRUN and the seimin bit.
Attention
When CoolStep increases motor current, spurious detection of motor stall may occur. For best results,
disable CoolStep during StallGuard based homing.
In case StallGuard is desired in combination with CoolStep, try increasing coolStep lower threshold
SEMIN as required.
12.3.1 Response Time
For fast response to increasing motor load, use a high current increment step SEUP. If the motor load
changes slowly, a lower current increment step can be used to avoid motor oscillations.
Hint
The most common and most beneficial use is to adapt CoolStep for operation at the typical system
target operation velocity and to set the velocity thresholds according. As acceleration and
decelerations normally shall be quick, they will require the full motor current, while they have only a
small contribution to overall power consumption due to their short duration.
12.3.2 Low Velocity and Standby Operation
Because CoolStep is not able to measure the motor load in standstill and at very low RPM, a lower
velocity threshold is provided for enabling CoolStep. It should be set to an application specific default
value. Below this threshold the normal current setting via IRUN respectively IHOLD is valid.
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13 STEP/DIR Interface
The STEP and DIR inputs provide a simple, standard interface compatible with many existing motion
controllers. The MicroPlyer step pulse interpolator brings the smooth motor operation of highresolution microstepping to applications originally designed for coarser stepping.
13.1 Timing
Figure 13.1 shows the timing parameters for the STEP and DIR signals, and the table below gives
their specifications. Only rising edges are active. STEP and DIR are sampled and synchronized to the
system clock. An internal analog filter removes glitches on the signals, such as those caused by long
PCB traces. If the signal source is far from the chip, and especially if the signals are carried on cables,
the signals should be filtered or differentially transmitted.
+VCC_IO
DIR
SchmittTrigger
tSH
tDSU
tSL
tDSH
STEP
or DIR
Input
STEP
83k
0.56 VCC_IO
0.44 VCC_IO
Internal
Signal
Active edge
(DEDGE=0)
Active edge
(DEDGE=0)
C
Input filter
R*C = 20ns +-30%
Figure 13.1 STEP and DIR timing, Input pin filter
STEP and DIR interface timing
AC-Characteristics
clock period is tCLK
Parameter
step frequency (at maximum
microstep resolution)
fullstep frequency
STEP input minimum low time
Symbol
fSTEP
STEP input minimum high time
tSH
DIR to STEP setup time
DIR after STEP hold time
STEP and DIR spike filtering time
*)
STEP and DIR sampling relative
to rising CLK input
tDSU
tDSH
Conditions
fFS
tSL
tFILTSD
tSDCLKHI
Min
Typ
Max
½ fCLK
Unit
max(tFILTSD,
tCLK+20)
max(tFILTSD,
tCLK+20)
100
ns
100
ns
20
ns
ns
ns
fCLK/512
rising and falling
edge
before rising edge
of CLK input
20
20
13
30
tFILTSD
*) These values are valid with full input logic level swing, only. Asymmetric logic levels will increase
filtering delay tFILTSD, due to an internal input RC filter.
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13.2 Changing Resolution
The TMC2209 includes an internal microstep table with 1024 sine wave entries to generate sinusoidal
motor coil currents. These 1024 entries correspond to one electrical revolution or four fullsteps. The
microstep resolution setting determines the step width taken within the table. Depending on the DIR
input, the microstep counter is increased (DIR=0) or decreased (DIR=1) with each STEP pulse by the
step width. The microstep resolution determines the increment respectively the decrement. At
maximum resolution, the sequencer advances one step for each step pulse. At half resolution, it
advances two steps. Increment is up to 256 steps for fullstepping. The sequencer has special
provision to allow seamless switching between different microstep rates at any time. When switching
to a lower microstep resolution, it calculates the nearest step within the target resolution and reads
the current vector at that position. This behavior especially is important for low resolutions like
fullstep and halfstep, because any failure in the step sequence would lead to asymmetrical run when
comparing a motor running clockwise and counterclockwise.
EXAMPLES:
Fullstep:
Cycles through table positions: 128, 384, 640 and 896 (45°, 135°, 225° and 315° electrical
position, both coils on at identical current). The coil current in each position
corresponds to the RMS-Value (0.71 * amplitude). Step size is 256 (90° electrical)
Half step:
The first table position is 64 (22.5° electrical), Step size is 128 (45° steps)
Quarter step: The first table position is 32 (90°/8=11.25° electrical), Step size is 64 (22.5° steps)
This way equidistant steps result and they are identical in both rotation directions. Some older drivers
also use zero current (table entry 0, 0°) as well as full current (90°) within the step tables. This kind of
stepping is avoided because it provides less torque and has a worse power dissipation in driver and
motor.
Step position
Half step 0
Full step 0
Half step 1
Half step 2
Full step 1
Half step 3
Half step 4
Full step 2
Half step 5
Half step 6
Full step 3
Half step 7
table position
64
128
192
320
384
448
576
640
704
832
896
960
current coil A
38.3%
70.7%
92.4%
92.4%
70.7%
38.3%
-38.3%
-70.7%
-92.4%
-92.4%
-70.7%
-38.3%
current coil B
92.4%
70.7%
38.3%
-38.3%
-70.7%
-92.4%
-92.4%
-70.7%
-38.3%
38.3%
70.7%
92.4%
See chapter 3.4 for resolution settings available in stand-alone mode.
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13.3 MicroPlyer Step Interpolator and Stand Still Detection
For each active edge on STEP, MicroPlyer produces microsteps at 256x resolution, as shown in Figure
13.2. It interpolates the time in between of two step impulses at the step input based on the last
step interval. This way, from 2 microsteps (128 microstep to 256 microstep interpolation) up to 256
microsteps (full step input to 256 microsteps) are driven for a single step pulse.
The step rate for the interpolated 2 to 256 microsteps is determined by measuring the time interval of
the previous step period and dividing it into up to 256 equal parts. The maximum time between two
microsteps corresponds to 220 (roughly one million system clock cycles), for an even distribution of
256 microsteps. At 12 MHz system clock frequency, this results in a minimum step input frequency of
roughly 12 Hz for MicroPlyer operation. A lower step rate causes a standstill event to be detected. At
that frequency, microsteps occur at a rate of (system clock frequency)/2 16 ~ 256 Hz. When a stand still
is detected, the driver automatically begins standby current reduction if selected by pin PDN.
Active edge
(dedge=0)
Active edge
(dedge=0)
Active edge
(dedge=0)
Active edge
(dedge=0)
Attention
MicroPlyer only works perfectly with a jitter-free STEP frequency.
STEP
Interpolated
microstep
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66
Motor
angle
2^20 tCLK
STANDSTILL
(stst) active
Figure 13.2 MicroPlyer microstep interpolation with rising STEP frequency (Example: 16 to 256)
In Figure 13.2, the first STEP cycle is long enough to set the stst bit standstill. Detection of standstill
will enable the standby current reduction. This bit is cleared on the next STEP active edge. Then, the
external STEP frequency increases. After one cycle at the higher rate MicroPlyer adapts the interpolated
microstep rate to the higher frequency. During the last cycle at the slower rate, MicroPlyer did not
generate all 16 microsteps, so there is a small jump in motor angle between the first and second
cycles at the higher rate.
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13.4 Index Output
An active INDEX output signals that the sine curve of motor coil A is at its positive zero transition.
This correlates to the zero point of the microstep sequence. Usually, the cosine curve of coil B is at its
maximum at the same time. Thus, the index signal is active once within each electrical period, and
corresponds to a defined position of the motor within a sequence of four fullsteps. The INDEX output
this way allows the detection of a certain microstep pattern, and thus helps to detect a position with
more precision than a stop switch can do.
Current
COIL A
0
COIL B
Time
INDEX
Current
Time
STEPS
Time
Figure 13.3 Index signal at positive zero transition of the coil A sine curve
Hint
The index output allows precise detection of the microstep position within one electrical wave, i.e.
within a range of four fullsteps. With this, homing accuracy and reproducibility can be enhanced to
microstep accuracy, even when using an inexpensive home switch.
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14 Internal Step Pulse Generator
UART
The TMC2209 family integrates a high-resolution step pulse generator, allowing motor motion via the
UART interface. However, no velocity ramping is provided. Ramping is not required, if the target
motion velocity is smaller than the start & stop frequency of the motor. For higher velocities, ramp up
the frequency in small steps to accelerate the motor, and ramp down again to decelerate the motor.
Figure 14.1 shows an example motion profile ramping up the motion velocity in discrete steps.
Choose the ramp velocity steps considerably smaller than the maximum start velocity of the motor,
because motor torque drops at higher velocity, and motor load at higher velocity typically increases.
motor
stop
v
acceleration
constant velocity
deceleration
Th
eo
re
t
ica
l
pr
of
ile
Target Velocity
Stop velocity
Start velocity
0
t
VACTUAL
Figure 14.1 Software generated motion profile
PARAMETER VS. UNITS
Parameter / Symbol
fCLK[Hz]
Unit
[Hz]
µstep velocity v[Hz]
µsteps / s
USC microstep count
counts
rotations per second v[rps]
rotations / s
TSTEP, TPWMTHRS
-
VACTUAL
Two’s complement
signed internal
velocity
calculation / description / comment
clock frequency of the TMC2209 in [Hz]
v[Hz] = VACTUAL[2209] * ( fCLK[Hz]/2 / 2^23 )
With internal oscillator:
v[Hz] = VACTUAL[2209] * 0.715Hz
microstep resolution in number of microsteps
(i.e. the number of microsteps between two
fullsteps – normally 256)
v[rps] = v[Hz] / USC / FSC
FSC: motor fullsteps per rotation, e.g. 200
TSTEP = fCLK / fSTEP
The time reference for velocity threshold is
referred to the actual microstep frequency of
the step input respectively velocity v[Hz].
VACTUAL[2209] = ( fCLK[Hz]/2 / 2^23 ) / v[Hz]
With internal oscillator:
VACTUAL[2209] = 0.715Hz / v[Hz]
Hint
To monitor internal step pulse execution, program the INDEX output to provide step pulses
(GCONF.index_step). It toggles upon each step. Use a timer input on your CPU to count pulses.
Alternatively, regularly poll MSCNT to grasp steps done in the previous polling interval. It wraps
around from 1023 to 0.
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15 Driver Diagnostic Flags
The TMC2209 drivers supply a complete set of diagnostic and protection capabilities, like short to GND
protection, short to VS protection and undervoltage detection. A detection of an open load condition
allows testing if a motor coil connection is interrupted. See the DRV_STATUS table for details.
15.1 Temperature Measurement
The driver integrates a four-level temperature sensor (pre-warning and thermal shutdown) for
diagnostics and for protection of the IC against excess heat. The thresholds can be adapted by UART
or OTP programming. Heat is mainly generated by the motor driver stages, and, at increased voltage,
by the internal voltage regulator. Most critical situations, where the driver MOSFETs could be
overheated, are avoided by the short to GND protection. For many applications, the overtemperature
pre-warning will indicate an abnormal operation situation and can be used to initiate user warning or
power reduction measures like motor current reduction. The thermal shutdown is just an emergency
measure and temperature rising to the shutdown level should be prevented by design.
TEMPERATURE THRESHOLDS
Overtemperature
Setting
143°C
(OTPW: 120°C)
150°C
(OTPW:
120°C or 143°C)
157°C
(OTPW: 143°C)
Comment
Default setting. This setting is safest to switch off the driver stage before the IC
can be destroyed by overheating. On a large PCB, the power MOSFETs reach
roughly 150°C peak temperature when the temperature detector is triggered with
this setting. This is a trip typical point for overtemperature shut down. The
overtemperature pre-warning threshold of 120°C gives lots of headroom to react
to high driver temperature, e.g. by reducing motor current.
Optional setting (OTP or UART). For small PCBs with high thermal resistance
between PCB and environment, this setting provides some additional headroom.
The small PCB shows less temperature difference between the MOSFETs and the
sensor.
Optional setting (UART). For applications, where a stop of the motor cannot be
tolerated, this setting provides highest headroom, e.g. at high environment
temperature ratings. Using the 143°C overtemperature pre-warning to reduce
motor current ensures that the motor is not switched off by the thermal
threshold.
Attention
Overtemperature protection cannot in all cases avoid thermal destruction
motor current is exceed, e.g. by operating a motor in StealthChop with
automatic tuning parameters not fitting the operating conditions, excess
heat up the driver before the overtemperature sensor can react. This
conduction over the IC die.
of the IC. In case the rated
wrong parameters, or with
heat generation can quickly
is due to a delay in heat
After triggering the overtemperature sensor (ot flag), the driver remains switched off until the system
temperature falls below the pre-warning level (otpw) to avoid continuous heating to the shutdown
level.
15.2 Short Protection
The TMC2209 power stages are protected against a short circuit condition by an additional measurement of the current flowing through each of the power stage MOSFETs. This is important, as most
short circuit conditions result from a motor cable insulation defect, e.g. when touching the conducting
parts connected to the system ground. The short detection is protected against spurious triggering,
e.g. by ESD discharges, by retrying three times before switching off the motor.
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Once a short condition is safely detected, the corresponding driver bridge (A or B) becomes switched
off, and the s2ga or s2gb flag, respectively s2vsa or s2vsb becomes set. In order to restart the motor,
disable and re-enable the driver. Note, that short protection cannot protect the system and the power
stages for all possible short events, as a short event is rather undefined and a complex network of
external components may be involved. Therefore, short circuits should basically be avoided.
15.3 Open Load Diagnostics
UART
Interrupted cables are a common cause for systems failing, e.g. when connectors are not firmly
plugged. The TMC2209 detects open load conditions by checking, if it can reach the desired motor coil
current. This way, also undervoltage conditions, high motor velocity settings or short and
overtemperature conditions may cause triggering of the open load flag, and inform the user, that
motor torque may suffer. In motor stand still, open load cannot always be measured, as the coils
might eventually have zero current.
Open load detection is provided for system debugging.
In order to safely detect an interrupted coil connection, read out the open load flags at low or
nominal motor velocity operation, only. If possible, use SpreadCycle for testing, as it provides the
most accurate test. However, the ola and olb flags have just informative character and do not cause
any action of the driver.
15.4 Diagnostic Output
The diagnostic output DIAG and the index output INDEX provide important status information. An
active DIAG output shows that the driver cannot work normally, or that a motor stall is detected,
when StallGuard is enabled. The INDEX output signals the microstep counter zero position, to allow
referencing (homing) a drive to a certain current pattern. The function set of the INDEX output can be
modified by UART. Figure 15.1 shows the available signals and control bits.
StallDetection
(gated by TPWMTHRS
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