LV8774Q
Bi-CDMOS LSI
PWM Constant-Current Control
Stepper Motor Driver
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Overview
The LV8774 is a 2-channel H-bridge driver IC, and can drive a stepper
motor or two brushed DC motors.
A stepper motor driver supports micro-step drive with 1/16-step resolution,
and two brushed motor drivers support forward, reverse, brake, and
standby functions. It is ideally suited for driving brushed DC motors and
stepper motors used in office equipment and amusement applications.
Feature
VQFN44L ( 6x6 )
Single-channel PWM current control stepper motor driver
(or two DC motor driver)
BiCDMOS process IC
Low on resistance (upper side : 0.3 ; lower side : 0.25 ;total of upper and lower : 0.55 ; Ta = 25C, IO = 2A)
Micro-step mode can be set to Full-step, Half-step, Quarter-step , or 1/16-step
Excitation step proceeds only by step signal input with stepper motor
Motor current selectable in four steps
Output short-circuit protection circuit (selectable from latch-type or auto-reset-type)
Unusual condition warning output pins
No control power supply required
Typical Applications
Stepper/Brush DC Motors , Computing & Peripherals , Industrial
Printers , Document Scanner , PoE Security Camera , Slot Machine , Vending Machine ,etc
Specifications
Absolute Maximum Ratings at Ta = 25C
Parameter
Symbol
Conditions
Ratings
Unit
Supply voltage
VM max
VM , VM1 , VM2
36
V
Output peak current
IO peak
Tw 10ms , duty 20% , Per 1ch
2.5
A
Output current
IO max
Per 1ch
2
A
Logic input voltage
VIN
ATT1, ATT2, EMM, RST/BLK, STEP/DC22,
-0.3 to +6
V
FR/DC21, MD2/DC12, MD1/DC11, DM, OE, ST
MONI/EMO input voltage
Vmoni/Vemo
Allowable power dissipation
Pd max
-0.3 to +6
V
3.60
W
Operating temperature
Storage temperature
Topr
-20 to +85
C
Tstg
-55 to +150
C
*
*Specified circuit board : 57.0mmx57.0mmx1.6mm, glass epoxy 4-layer board, with backside mounting.
Caution 1) Absolute maximum ratings represent the value which cannot be exceeded for any length of time.
Caution 2) Even when the device is used within the range of absolute maximum ratings, as a result of continuous usage under high temperature, high current,
high voltage, or drastic temperature change, the reliability of the IC may be degraded. Please contact us for the further details.
Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality should not be assumed,
damage may occur and reliability may be affected.
ORDERING INFORMATION
See detailed ordering and shipping information on page 28 of this data sheet.
© Semiconductor Components Industries, LLC, 2015
June 2015 - Rev. 2
1
Publication Order Number :
LV8774Q/D
LV8774Q
Recommended Operating Conditions at Ta = 25C
Parameter
Symbol
Conditions
Ratings
Unit
Supply voltage range
VM
VM , VM1 , VM2
9 to 32
V
Logic input voltage
VIN
ATT1 , ATT2 , EMM , RST/BLK , STEP/DC22 ,
0 to 5.5
V
0 to 3
V
FR/DC21 , MD2/DC12 , MD1/DC11 , DM , OE , ST
VREF input voltage range
VREF
Functional operation above the stresses listed in the Recommended Operating Ranges is not implied. Extended exposure to stresses beyond the Recommended
Operating Ranges limits may affect device reliability.
Electrical Characteristics at Ta = 25°C, VM = 24V, VREF = 1.5V
Parameter
Symbol
Conditions
Ratings
min
typ
Unit
max
Standby mode current drain
IMst
ST = “L” , I(VM)+I(VM1)+I(VM2)
100
400
A
Current drain
IM
ST = “H”, OE = “L”, with no load
3.2
5
mA
VREG5 output voltage
Vreg5
IO = -1mA
4.5
5
5.5
V
Thermal shutdown temperature
TSD
Design guarantee
150
180
200
C
Thermal hysteresis width
TSD
Design guarantee
I(VM)+I(VM1)+I(VM2)
C
40
Motor driver
Output on resistance
Ronu
IO = 2A, Upper-side on resistance
0.3
0.4
Rond
IO = 2A, Lower-side on resistance
0.25
0.33
50
A
1.2
1.4
V
4
8
12
A
30
50
70
A
Output leakage current
IOleak
Diode forward voltage
VD
ID = -2A
Logic pin input current
IINL
ATT1 , ATT2 , EMM , RST/BLK ,
STEP/DC22 , FR/DC21 , MD2/DC12 ,
IINH
MD1/DC11 , DM , OE , ST , VIN = 0.8V
ATT1 , ATT2 , EMM , RST/BLK ,
STEP/DC22 , FR/DC21 , MD2/DC12 ,
MD1/DC11 , DM , OE , ST , VIN = 5V
Logic input voltage
High
VINh
ATT1 , ATT2 , EMM , RST/BLK ,
Low
VINl
STEP/DC22 , FR/DC21 , MD2/DC12 ,
Current setting
1/16 step
Vtdac0_4W
Step 0 (When initialized : channel 1
comparator
resolution
2.0
5.5
V
0
0.8
V
0.309
V
MD1/DC11 , DM , OE , ST
0.291
0.3
comparator level)
threshold voltage
Vtdac1_4W
Step 1 (Initial state+1)
0.291
0.3
0.309
V
(current step
Vtdac2_4W
Step 2 (Initial state+2)
0.285
0.294
0.303
V
Vtdac3_4W
Step 3 (Initial state+3)
0.279
0.288
0.297
V
Vtdac4_4W
Step 4 (Initial state+4)
0.267
0.276
0.285
V
Vtdac5_4W
Step 5 (Initial state+5)
0.255
0.264
0.273
V
Vtdac6_4W
Step 6 (Initial state+6)
0.240
0.249
0.258
V
Vtdac7_4W
Step 7 (Initial state+7)
0.222
0.231
0.240
V
Vtdac8_4W
Step 8 (Initial state+8)
0.201
0.21
0.219
V
Vtdac9_4W
Step 9 (Initial state+9)
0.180
0.189
0.198
V
Vtdac10_4W
Step 10 (Initial state+10)
0.157
0.165
0.173
V
Vtdac11_4W
Step 11 (Initial state+11)
0.134
0.141
0.148
V
Vtdac12_4W
Step 12 (Initial state+12)
0.107
0.114
0.121
V
Vtdac13_4W
Step 13 (Initial state+13)
0.080
0.087
0.094
V
Vtdac14_4W
Step 14 (Initial state+14)
0.053
0.06
0.067
V
switching)
Quarter step
Vtdac15_4W
Step 15 (Initial state+15)
0.023
0.03
0.037
V
Vtdac0_W
Step 0 (When initialized : channel 1
0.291
0.3
0.309
V
0.276
0.285
V
resolution
comparator level)
Vtdac4_W
Step 4 (Initial state+1)
0.267
Vtdac8_W
Step 8 (Initial state+2)
0.201
0.21
0.219
V
Vtdac12_W
Step 12 (Initial state+3)
0.107
0.114
0.121
V
Continued on next page
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2
LV8774Q
Continued from preceding page.
Parameter
Current setting
Half step
comparator
resolution
threshold voltage
Symbol
Vtdac0_H
Conditions
Step 0 (When initialized : channel 1
Ratings
min
typ
Unit
max
0.291
0.3
0.309
V
comparator level)
Vtdac8_H
Step 8 (Initial state+1)
0.201
0.21
0.219
V
Vtdac8_F
Step 8' (When initialized : channel 1
0.291
0.3
0.309
V
Current setting comparator
Vtatt00
ATT1 = L, ATT2 = L
0.291
0.3
0.309
V
threshold voltage
Vtatt01
ATT1 = H, ATT2 = L
0.232
0.24
0.248
V
Vtatt10
ATT1 = L, ATT2 = H
0.143
0.15
0.157
V
Vtatt11
ATT1 = H, ATT2 = H
0.053
0.06
0.067
V
Chopping frequency
Fchop
Cchop = 200pF
40
50
60
kHz
CHOP pin charge/discharge current
Ichop
7
10
13
A
Chopping oscillation circuit
Vtup
0.8
1
1.2
V
threshold voltage
Vtdown
0.4
0.5
0.6
V
400
mV
(current step
Full step
switching)
resolution
(current attenuation rate switching)
comparator level)
VREF pin input current
Iref
VREF = 1.5V
MONI pin saturation voltage
Vsatmon
Imoni = 1mA
A
-0.5
Charge pump
VG output voltage
VG
Rise time
tONG
Oscillator frequency
Fosc
28
VG = 0.1F , Between CP1-CP2 0.1uF
28.7
29.8
V
200
500
S
125
150
kHz
400
mV
ST=”H” →VG=VM+4V
90
Output short-circuit protection
EMO pin saturation voltage
Vsatemo
Iemo = 1mA
CEM pin charge current
Icem
Vcem = 0V
CEM pin threshold voltage
Vtcem
7
10
13
A
0.8
1
1.2
V
Product parametric performance is indicated in the Electrical Characteristics for the listed test conditions, unless otherwise noted. Product performance may not be
indicated by the Electrical Characteristics if operated under different conditions.
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LV8774Q
Package Dimensions
unit : mm (typ)
VQFN44L(6mm x 6mm)
Pdmax-Ta
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LV8774Q
Substrate Specifications (Substrate recommended for operation of LV8774Q)
Size
: 57mm × 57mm × 1.6mm (four-layer substrate)
Material
: Glass epoxy
Copper wiring density : L1 = 75% / L4 = 85%
L1 : Copper wiring pattern diagram
L4 : Copper wiring pattern diagram
Cautions
1) The data for the case with the back side mounted shows the values when 90% or more of the Exposed Die-Pad is wet.
2) For the set design, employ the derating design with sufficient margin.
Stresses to be derated include the voltage, current, junction temperature, power loss, and mechanical stresses such as
vibration, impact, and tension.
Accordingly, the design must ensure these stresses to be as low or small as possible.
The guideline for ordinary derating is shown below :
(1)Maximum value 80% or less for the voltage rating
(2)Maximum value 80% or less for the current rating
(3)Maximum value 80% or less for the temperature rating
3) After the set design, be sure to verify the design with the actual product.
Confirm the solder joint state and verify also the reliability of solder joint for the Exposed Die-Pad, etc.
Any void or deterioration, if observed in the solder joint of these parts, causes deteriorated thermal conduction,
possibly resulting in thermal destruction of IC.
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5
MONI
CHOP
EMM
CEM
EMO
ATT1
OUT1B
OUT1B
RF1
RF1
NC
NC
OUT2A
FR/DC21
STEP/DC22
RF2
RST/BLK
MD2/DC12
RF2
OUT2A
MD1/DC11
NC
LV8774Q
Pin Assignment
VQFN44L(6mm×6mm )
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6
MONI
PGND
VM
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7
GND
VREF
VREG5
+
-
LVS
TSD
+
-
CHOP
Oscillation
circuit
Regulator
ATT2
Attenuator
(4 levels
selectable)
ST ATT1
Charge pump
Output preamplifier stage
RF
OUT B VM
VM2 OUT2A
RF2
DM
EMM
Current
selection
(4W1-2/
W1-2/1-2/2)
Current
selection
(4W1-2/
W1-2/1-2/2)
MD1/ MD2/ FR/ STEP/ RST/ OE
DC11 DC12 DC21 DC22 BLK
+
Output control logic
OUT2B
+
OUT A
Output preamplifier stage
VG
Output preamplifier stage
CF
Output preamplifier stage
CP2
CEM
EMO
LV8774Q
Block Diagram
LV8774Q
Pin Functions
Pin No.
Pin Name
Pin Function
22
ATT2
Motor holding current switching pin.
23
ATT1
Motor holding current switching pin.
26
EMM
Output short-circuit protection mode
29
RST/BLK
30
STEP/DC22
31
FR/DC21
Equivalent Circuit
VREG5
switching pin.
RESET input pin (STM) / Blanking time
switching pin (DCM).
STEP signal input pin (STM) / Channel 2
output control input pin 2 (DCM).
CW / CCW signal input pin (STM) /
10kΩ
Channel 2 output control input pin 1
(DCM).
32
MD2/DC12
Excitation mode switching pin 2 (STM) /
100kΩ
Channel 1 output control input pin 2
(DCM).
33
MD1/DC11
Excitation mode switching pin 1 (STM) /
Channel 1 output control input pin 1
GND
(DCM).
35
DM
Drive mode (STM/DCM) switching pin.
36
OE
Output enable signal input pin.
37
ST
Chip enable pin.
VREG5
20kΩ
10kΩ
80kΩ
GND
40, 41
OUT2B
Channel 2 OUTB output pin.
14, 42
PGND
Power system ground.
43, 44
VM2
Channel 2 motor power supply
2, 3
RF2
5, 6
OUT2A
Channel 2 OUTA output pin.
7, 8
OUT1B
Channel 1 OUTB output pin.
9, 10
RF1
Channel 1 current-sense resistor
12 13
43 44
connection pin.
Channel 2 current-sense resistor
connection pin.
15 16
5
connection pin.
12, 13
VM1
Channel 1 motor power supply pin.
15, 16
OUT1A
Channel 1 OUTA output pin.
7 8
6
40 41
14 42
9 10
2 3
Continued on next page.
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LV8774Q
Continued from preceding page.
Pin No.
Pin Name
Pin Function
17
VG
Charge pump capacitor connection pin.
18
VM
Motor power supply connection pin.
19
CP2
Charge pump capacitor connection pin.
20
CP1
Charge pump capacitor connection pin.
38
VREF
Equivalent Circuit
20
Constant current control reference
18
19
17
VREG5
voltage input pin.
500Ω
GND
21
VREG5
Internal power supply capacitor
VM
connection pin.
2kΩ
78kΩ
26kΩ
GND
24
EMO
Output short-circuit state warning output
VREG5
pin.
28
MONI
Position detection monitor pin.
GND
Continued on next page.
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LV8774Q
Continued from preceding page.
Pin No.
25
Pin Name
CEM
Pin Function
Equivalent Circuit
Pin to connect the output short-circuit
VREG5
state detection time setting capacitor.
GND
27
CHOP
Chopping frequency setting capacitor
VREG5
connection pin.
500Ω
GND
39
1,4,11,
34
ExposedPad
GND
NC
Ground.
No Connection
(No internal connection to the IC)
Exposed-Pad connects signal GND or
floating.*
*Recommendation is to connect Exposed-pad to signal GND.
Since IC may generate heat when using it by floating, be careful of a thermal design enough.
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500Ω
LV8774Q
Description of operation
1. Input Pin Function
Each input terminal has the function to prevent the flow of the current from an input to a power supply.
Therefore, Even if a power supply (VM) is turned off in the state that applied voltage to an input terminal, the electric
current does not flow into the power supply.
1-1) Chip enable function
This IC is switched between standby and operating mode by setting the ST pin. In standby mode, the IC is set to
power-save mode and all logic is reset. In addition, the internal regulator circuit and charge pump circuit do not
operate in standby mode.
ST
Mode
Internal regulator
Charge pump
Low or Open
Standby mode
Standby
Standby
High
Operating mode
Operating
Operating
1-2) Drive mode switching pin function
The IC drive mode is switched by setting the DM pin. In STM mode, stepper motor channel 1 can be controlled by the
CLK-IN input. In DCM mode, DC motor channel 2 or stepper motor channel 1 can be controlled by parallel input.
Stepper motor control using parallel input is Full-step or Half-step full torque.
DM
Drive mode
Application
Low or Open
STM mode
Stepper motor channel 1 (CLK-IN)
High
DCM mode
DC motor channel 2 or stepper motor channel 1 (parallel)
2. STM mode (DM = Low or Open)
2-1) STEP pin function
Input
Operating mode
ST
STP
Low
*
Standby mode
High
Excitation step proceeds
High
Excitation step is kept
2-2) Excitation mode setting function
MD1
MD2
Micro-step resolution
(Excitation mode)
Initial position
Channel 1
Channel 2
Low
Low
Full step(2 phase excitation)
100%
-100%
High
Low
Half step(1-2 phase excitation)
100%
0%
Low
High
Quarter step
100%
0%
100%
0%
(W1-2 phase excitation)
High
High
1/16 step(4W1-2 phase excitation)
This is the initial position of each excitation mode in the initial state after power-on and when the counter is reset.
2-3) Position detection monitoring function
The MONI position detection monitoring pin is of an open drain type.
When the excitation position is in the initial position, the MONI output is placed in the ON state.
(Refer to "2-12.Examples of current waveforms in each micro-step mode.")
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LV8774Q
2-4) Setting constant-current control reference current
This IC is designed to automatically exercise PWM constant-current chopping control for the motor current by setting
the output current. Based on the voltage input to the VREF pin and the resistance connected between RF and GND,
the output current that is subject to the constant-current control is set using the calculation formula below :
IOUT = (VREF/5)/RF resistance
* The above setting is the output current at 100% of each excitation mode.
The voltage input to the VREF pin can be switched to four-step settings depending on the statuses of the two inputs,
ATT1 and ATT2. This is effective for reducing power consumption when motor holding current is supplied.
Attenuation function for VREF input voltage
ATT1
ATT2
Current setting reference voltage attenuation ratio
Low
Low
100%
High
Low
80%
Low
High
50%
High
High
20%
The formula used to calculate the output current when using the function for attenuating the VREF input voltage is
given below.
IOUT = (VREF/5) × (attenuation ratio)/RF resistance
Example : At VREF of 1.5V, a reference voltage setting of 100% [(ATT1, ATT2) = (L, L)] and an RF resistance of
0.3, the output current is set as shown below.
IOUT = 1.5V/5 × 100%/0.3 = 1.0A
If, in this state, (ATT1, ATT2) is set to (H, H), IOUT will be as follows :
IOUT = 1.0A × 20% = 200mA
In this way, the output current is attenuated when the motor holding current is supplied so that power can
be conserved.
2-5) Input Timing
TstepH TstepL
STEP
Tdh
Tds
(md1 step) (step md1)
MD1
Tdh
Tds
(md2 step) (step md2)
MD2
Tdh
Tds
(fr step) (step fr)
FR
TstepH/TstepL : Clock H/L pulse width (min 500ns)
Tds : Data set-up time (min 500ns)
Tdh : Data hold time (min 500ns)
2-6) Blanking period
During normal operation switching transient noise from the parasitic diode may flow to the current sensing resistance,
resulting in erroneous detection. To prevent this erroneous detection, a blanking period is provided to prevent the
noise from being received.
In the stepper motor driver mode (DM = Low or Open) of this IC, the blanking time is fixed at approximately 1s.
In the DC motor driver mode (DM = High), the blanking time can be switched to one of two levels using the
RST/BLK pin. (Refer to "Blanking time switching function.")
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LV8774Q
2-7) Reset function
RST
Operating mode
Low
Normal operation
High
Reset state
RST
RESET
STEP
MONI
1ch output
0%
2ch output
Initial state
When the RST pin is set to High, the excitation position of the output is forcibly set to the initial state, and the MONI
output is placed in the ON state. When RST is then set to Low, the excitation position is advanced by the next STEP
input.
2-8) Output enable function
OE
Operating mode
Low
Output ON
High
Output OFF
OE
Power save mode
STEP
MONI
1ch output
0%
2ch output
Output is high-impedance
When the OE pin is set High, the output is forced OFF and goes to high impedance.
The internal logic circuits remain operating, and the excitation position proceeds when the STEP signal is inputted.
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LV8774Q
2-9) Forward/reverse switching function
FR
Operating mode
Low
Clockwise (CW)
High
Counter-clockwise (CCW)
FR
CW mode
CCW mode
CW mode
STEP
Excitation position
(1)
(2)
(3)
(4)
(5)
(6)
(5)
(4)
(3)
(4)
(5)
1ch output
2ch output
The internal D/A converter proceeds by one bit at the rising edge of the input STEP pulse.
In addition, CW and CCW mode are switched by setting the FR pin.
In CW mode, the channel 2 current phase is delayed by 90° relative to the channel 1 current.
In CCW mode, the channel 2 current phase is advanced by 90° relative to the channel 1 current.
2-10) Chopping frequency setting
For constant-current control, this IC performs chopping operations at the frequency determined by the capacitor
(Cchop) connected between the CHOP pin and GND.
The chopping frequency is set as shown below by the capacitor (Cchop) connected between the CHOP pin and GND.
Fchop = Ichop/ (Cchop × Vtchop × 2) (Hz)
Ichop : Capacitor charge/discharge current, typ 10A
Vtchop : Charge/discharge hysteresis voltage (Vtup-Vtdown), typ 0.5V
For instance, when Cchop is 200pF, the chopping frequency will be as follows :
Fchop = 10A/ (200pF × 0.5V × 2) = 50kHz
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LV8774Q
2-11) Output current vector locus (one step is normalized to 90 degrees)
100.0
θ0
θ1
θ2
θ8' (2-phase)
θ3
θ4
θ5
θ6
Channel 1 phase current ratio (%)
θ7
θ8
66.7
θ9
θ 10
θ 11
θ 12
33.3
θ 13
θ 14
θ 15
θ 16
0.0
0.0
33.3
66.7
100.0
Channel 2 current ratio (%)
Setting current ration in each micro-step mode
STEP
1/16 step (%)
Channel 1
Quarter step (%)
Channel 2
Channel 1
0
100
0
1
100
10
2
98
20
3
96
29
4
92
38
5
88
47
6
83
55
7
77
63
8
70
70
9
63
77
10
55
83
11
47
88
12
38
92
13
29
96
14
20
98
15
10
100
16
0
100
Half step (%)
Channel 2
Channel 1
100
0
92
38
70
70
38
92
0
100
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Full step (%)
Channel 2
Channel 1
100
0
70
70
0
100
100
Channel 2
100
LV8774Q
2-12) Examples of current waveforms in each micro-step mode
Full step (CW mode)
STEP
MONI
(%)
100
l1
0
-100
(%)
100
I2
0
-100
Half step (CW mode)
STEP
MONI
(%)
100
I1
0
-100
(%)
100
I2
0
-100
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LV8774Q
Quarter step (CW mode)
STEP
MONI
(%)
100
I1
0
-100
(%)
100
I2
0
-100
1/16 step (CW mode)
STEP
MONI
(%)
100
50
I1
0
-50
-100
(%)
100
50
I2
0
-50
-100
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LV8774Q
2-13) Current control operation specification
(Sine wave increasing direction)
STEP
Set current
Set current
Coil current
Forced CHARGE
section
fchop
Current mode CHARGE
SLOW
FAST
CHARGE
SLOW
FAST
(Sine wave decreasing direction)
STEP
Set current
Coil current
Forced CHARGE
section
Set current
fchop
Current mode CHARGE
SLOW
Forced CHARGE
section
FAST
FAST
CHARGE
SLOW
For current mode control, the operation sequence is as described below :
At rise of chopping frequency, the CHARGE mode begins. (During blanking time the CHARGE mode is forced
regardless of the magnitude of the coil current (ICOIL) and set current (IREF).)
The coil current (ICOIL) and set current (IREF) are compared in this blanking time.
When (ICOIL < IREF)
the winding is charged until ICOIL IREF, then changed to the SLOW DECAY mode, and finally to the
FAST DECAY mode for approximately 1s.
When (ICOIL IREF)
the FAST DECAY mode begins immediately. The coil current is attenuated in the FAST DECAY for one
cycle.
Above operations are repeated. Normally, the SLOW (+FAST) DECAY mode continues in the sine wave increasing
direction, then entering the FAST DECAY mode till the current is attenuated to the set level, followed by the SLOW
DECAY mode.
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LV8774Q
3.
DCM Mode (DM=High)
3-1) DCM mode output control logic
Parallel input
Output
Mode
DC11 (21)
DC12 (22)
OUT1 (2) A
OUT1 (2) B
Low
Low
OFF
OFF
Standby
High
Low
High
Low
CW (Forward)
Low
High
Low
High
CCW (Reverse)
High
High
Low
Low
Brake
3-2) Blanking time switching function
BLK
Blanking time
Low
2s
High
3s
3-3) Output enable function
OE
Operating mode
Low
Output ON
High
Output OFF
When the OE pin is set High, the output is forced OFF and goes to high impedance. When the OE pin is set Low,
output conforms to the control logic.
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LV8774Q
3-4) Current limit reference voltage setting function
By setting a current limit, this IC automatically exercises shorted braking control to ensure that the motor current
cannot exceed this limit.
(Current limit control time chart)
Set current
Current mode
Coil current
Forced CHARGE
section
fchop
Current mode
CHARGE
SLOW
The limit current is set as calculated on the basis of the voltage input to the VREF pin and the resistance between the
RF pin and GND using the formula given below.
Ilimit = (VREF/5) /RF resistance
The voltage applied to the VREF pin can be switched to any of the four setting levels depending on the statuses of the
two inputs, ATT1 and ATT2.
Function for attenuating VREF input voltage
ATT1
ATT2
Current setting reference voltage attenuation ratio
Low
Low
100%
High
Low
80%
Low
High
50%
High
High
20%
The formula used to calculate the output current when using the function for attenuating the VREF input voltage is
given below.
Ilimit = (VREF/5) × (attenuation ratio) /RF resistance
Example : At VREF of 1.5V, a reference voltage setting of 100% [(ATT1, ATT2) = (L, L)] and an RF resistance of
0.3, the output current is set as shown below.
Ilimit = 1.5V/5 × 100%/0.3 = 1.0A
If, in this state, (ATT1, ATT2) has been set to (H, H), Ilimit will be as follows :
Ilimit = 1.0A × 20% = 200mA
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LV8774Q
3-5) Examples of current waveform in each micro-step mode with stepper motor parallel input control
Full step (CW mode)
DC11
DC12
DC21
DC22
(%)
100
I1
0
-100
(%)
100
I2
0
-100
Half step full torque (CW mode)
DC11
DC12
DC21
DC22
(%)
100
l1
0
-100
(%)
100
l2
0
-100
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LV8774Q
4. Output short-circuit protection function
This IC incorporates an output short-circuit protection circuit that, when the output has been shorted by an event such
as shorting to power or shorting to ground, sets the output to the standby mode and turns on the warning output in
order to prevent the IC from being damaged. In the stepper motor driver (STM) mode (DM = Low), this function sets
the output to the standby mode for both channels by detecting the short-circuiting in one of the channels. In the DC
motor driver mode (DM = High), channels 1 and 2 operate independently. (Even if the output of channel 1 has been
short-circuited, channel 2 will operate normally.)
4-1) Output short-circuit protection mode switching function
Output short-circuit protection mode of IC can be switched by the setting of EMM pin.
EMM
State
Low or Open
Latch method
High
Auto reset method
4-2) Latch type
In the latch mode, when the output current exceeds the detection current level, the output is turned OFF, and this state
is held.
The detection of the output short-circuited state by the IC causes the output short-circuit protection circuit to be
activated.
When the short-circuited state continues for the period of time set using the internal timer (approximately 2s), the
output in which the short-circuiting has been detected is first set to OFF. After this, the output is set to ON again as
soon as the timer latch time (Tcem) described later has been exceeded, and if the short-circuited state is still detected,
all the outputs of the channel concerned are switched to the standby mode, and this state is held.
This state is released by setting ST to low.
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LV8774Q
4-3) Auto reset type
In the automatic reset mode, when the output current exceeds the detection current level, the output waveform
changes to the switching waveform.
As with the latch system, when the output short-circuited state is detected, the short-circuit protection circuit is
activated. When the operation of the short-circuit detection circuit exceeds the timer latch time (Tcem) described later,
the output is changed over to the standby mode and is reset to the ON mode again in 2ms (typ). In this event, if the
over current mode still continues, the switching mode described above is repeated until the over current mode is
canceled.
4-4) Unusual condition warning output pins (EMO, MONI)
The LV8774 is provided with the EMO pin which notifies the CPU if the protection circuit detects an unusual
condition of the IC. This pin is of the open-drain output type and when an unusual condition is detected, the EMO
output is placed in the ON (EMO = Low) state.
In the DC motor driver mode (DM = High), the MONI pin also functions as a warning output pin.
The functions of the EMO pin and MONI pin change function as shown below depending on the state of the DM pin.
When the DM is low (STM mode) :
EMO : Unusual condition warning output pin
MONI : Excitation initial position detection monitoring
When the DM is high (DCM) mode) :
EMO : Channel 1 warning output pin
MONI : Channel 2 warning output pin
The EMO (MONI) pin is also placed in the ON state when one of the following conditions occurs.
1. Shorting-to-power, shorting-to-ground, or shorting-to-load occurs at the output pin and the output short-circuit
protection circuit is activated.
2. The IC junction temperature rises and the thermal protection circuit is activated.
Unusual condition
DM = L (STM mode)
DM = H (DCM mode)
EMO
MONI
EMO
Channel 1 short-circuit detected
ON
-
ON
MONI
-
Channel 2 short-circuit detected
ON
-
-
ON
Overheating condition detected
ON
-
ON
ON
4-5) Timer latch time (Tcem)
The time taken for the output to be set to OFF when the output has been short-circuited can be set using capacitor
Ccem, connected between the CEM pin and GND. The value of capacitor Ccem is determined by the formula given
below.
Timer latch : Tcem
5.
Tcem Ccem Vtcem/Icem [sec]
Vtcem : Comparator threshold voltage, typ 1V
Icem : CEM pin charge current, typ 10A
Thermal shutdown function
The thermal shutdown circuit is included, and the output is turned off when junction temperature Tj exceeds 180°C
and the abnormal state warning output is turned on at the same time.
When the temperature falls below the hysteresis level, output is driven again (automatic restoration)
The thermal shutdown circuit doesn’t guarantee protection of the set and the destruction prevention of IC, as it
operates at a temperature that is higher than the rating (Tjmax=150°C) of the junction temperature
TTSD = 180°C (typ)
ΔTSD = 40°C (typ)
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LV8774Q
6. Charge Pump Circuit
When the ST pin is set High, the charge pump circuit operates and the VG pin voltage is boosted from the VM voltage
to the VM + VREG5 voltage.
If the VG pin voltage is not boosted to VM+4V or more, the output pin cannot be turned on. Therefore it is
recommended that the drive of motor is started after the time has passed tONG or more.
ST
VG pin voltage
VM+VREG5
VM+4V
VM
tONG
VG Pin Voltage Schematic View
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LV8774Q
Application Circuit Example
Short-circuit state
detection monitor
Logic
input
Clock input
Position detection monitor
Stepper motor driver circuit (DM = Low)
200pF
100pF
47kΩ
1.5V
28
27
26
FR/DC21
RST/BLK
MONI
CHOP
EMM
25
24
23
ATT1
29
CEM
30
EMO
31
STEP/DC22
32
MD2/DC12
34 NC
33
MD1/DC11
47kΩ
ATT2 22
35 DM
VREG5 21
36 OE
CP1 20
37 ST
CP2 19
VM 18
38 VREF
LV8774
39 GND
0.1uF
0.1uF
0.1uF
VG 17
40 OUT2B
OUT1A 16
41 OUT2B
OUT1A 15
42 PGND
PGND 14
RF2
NC
OUT2A
OUT2A
OUT1B
OUT1B
RF1
RF1
NC
VM1 12
RF2
VM1 13
44 VM2
NC
43 VM2
1
2
3
4
5
6
7
8
9
10
11
0.22Ω
24V
10uF
0.22Ω
M
The formulae for setting the constants in the example of the application circuit above are as follows :
Constant current (100%) setting
When VREF = 1.5V
IOUT = VREF/5/RF resistance
= 1.5V/5/0.22 = 1.36A
Chopping frequency setting
Fchop = Ichop/ (Cchop × Vtchop × 2)
= 10A/ (200pF × 0.5V × 2) = 50kHz
Timer latch time when the output is short-circuited
Tcem = Ccem × Vtcem/Icem
= 100pF × 1V/10A = 10s
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LV8774Q
Channel 1 short-circuit
state detection monitor
Logic
input
Channel 2 short-circuit
state detection monitor
DC motor driver circuit (DM = High, and the current limit function is in use.)
200pF
100pF
47kΩ
28
27
26
FR/DC21
STEP/DC22
RST/BLK
MONI
CHOP
EMM
25
24
23
ATT1
29
CEM
30
EMO
31
ATT2 22
35 DM
VREG5 21
36 OE
CP1 20
37 ST
CP2 19
38 VREF
VM 18
39 GND
VG 17
40 OUT2B
OUT1A 16
41 OUT2B
OUT1A 15
42 PGND
PGND 14
OUT2A
OUT2A
OUT1B
OUT1B
RF1
RF1
NC
VM1 12
NC
44 VM2
RF2
VM1 13
RF2
43 VM2
NC
1.5V
32
MD2/DC12
34 NC
33
MD1/DC11
47kΩ
1
2
3
4
5
6
7
8
9
10
11
0.22Ω
0.1uF
0.1uF
0.1uF
0.22Ω
M
M
The formulae for setting the constants in the example of the application circuit above are as follows :
Constant current limit (100%) setting
When VREF = 1.5V
Ilimit = VREF/5/RF resistance
= 1.5V/5/0.22 = 1.36A
Chopping frequency setting
Fchop = Ichop/ (Cchop × Vtchop × 2)
= 10A/ (200pF × 0.5V × 2) = 50kHz
Timer latch time when the output is short-circuited
Tcem = Ccem × Vtcem/Icem
= 100pF × 1V/10A = 10s
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24V
10uF
LV8774Q
EMM
CEM
EMO
ATT1
OUT1B
RF1
RF1
NC
Short-circuit state
detection monitor
CHOP
OUT1B
MONI
NC
OUT2A
FR/DC21
STEP/DC22
RF2
RST/BLK
MD2/DC12
RF2
OUT2A
MD1/DC11
NC
Logic
input
Short-circuit state
detection monitor
High current DC motor driver circuit (DM = High, and the current limit function cannot be used.)
LV8774Q can drive a large current DC motor by connecting two H-bridges to parallel.
Iomax = 4A
Iopeak = 5A (tw 10ms, duty 20%)
When it connects two H-bridges to parallel, LV8774Q cannot use the internal PWM constant current control function.
Please connect the RF1 pin and RF2 pin to GND.
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LV8774Q
ORDERING INFORMATION
Device
LV8774Q-AH
Package
VQFN44L (6mm 6mm)
(Pb-Free / Halogen Free)
Shipping (Qty / Packing)
1000 / Tape & Reel
† For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel
Packaging Specifications Brochure, BRD8011/D. http://www.onsemi.com/pub_link/Collateral/BRD8011-D.PDF
ON Semiconductor and the ON logo are registered trademarks of Semiconductor Components Industries, LLC (SCILLC) or its subsidiaries in the United States
and/or other countries. SCILLC owns the rights to a number of patents, trademarks, copyrights, trade secrets, and other intellectual property. A listing of
SCILLC’s product/patent coverage may be accessed at www.onsemi.com/site/pdf/Patent-Marking.pdf . SCILLC reserves the right to make changes without
further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose,
nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including
without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can
and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each
customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights nor the rights of others. SCILLC products are
not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or
sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should
Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers,
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directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was
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applicable copyright laws and is not for resale in any manner.
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