MP6532
5V to 60V, Three-Phase Brushless
DC Motor Pre-Driver
DESCRIPTION
FEATURES
The MP6532 is a gate driver IC designed for
three-phase brushless DC motor driver
applications. It is capable of driving three half
bridges consisting of six N-channel power
MOSFETs up to 60V.
The MP6532 integrates a regulated charge pump
to generate gate drive power, and uses a
bootstrap capacitor to generate a supply voltage
for the high-side MOSFET driver. An internal
trickle-charge circuit maintains sufficient highside gate driver voltage even when an output is
operated at 100% duty cycle
Internal
protection
features
include
programmable short-circuit protection, overcurrent protection, adjustable dead-time control,
undervoltage lockout, and thermal shutdown.
Wide 5V to 60V Input Voltage Range
Built-in Hall Sensor Inputs and 120°
Commutation Logic
Charge Pump Gate Drive Supply
Bootstrap High-Side Driver with TrickleCharge Circuit Supports 100% Duty Cycle
Operation
Low-Power Sleep Mode
Programmable Short-Circuit Protection
Over-Current Protection
Adjustable Dead-Time Control to Prevent
Shoot-Through
Thermal Shutdown and UVLO Protection
Fault Indication Output
Thermally Enhanced Surface-Mount Package
APPLICATIONS
The device integrates 120° commutation using
three Hall sensor inputs. The PWM, DIR, and
nBRAKE inputs are used to control motor speed,
direction, and braking.
The MP6532 is available in 28-pin, 9.7mm ×
6.4mm TSSOP and 4mm x 4mm QFN packages
with an exposed thermal pad.
Three-Phase Brushless DC Motors and
Permanent Magnet Synchronous Motors
Power Drills
Impact Drivers
E-Bike
All MPS parts are lead-free, halogen-free and adhere to the RoHS directive.
For MPS green status, please visit MPS website under Quality Assurance.
“MPS” and “The Future of Analog IC Technology” are registered trademarks of
Monolithic Power Systems, Inc.
TYPICAL APPLICATION
MP6532
CPA
DT
CPB
RDT
0.47uF
10uF
VIN
VREG
VIN
nFAULT
CIN
OCREF
BSTA
nSLEEP
DIR
GHA
PWM
SHA
To
Phase
C
nBRAKE
HA
HB
To
Phase
B
GLA
LSS
HC
Phase A
(repeat for B and C)
GND
MP6532 Rev. 1.23
8/9/2018
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© 2018 MPS. All Rights Reserved.
1
MP6532 – 5V TO 60V, THREE PHASE BLDC MOTOR PRE-DRIVER
ORDERING INFORMATION
Part Number
Package
Top Marking
MP6532GR*
QFN-28 (4mm x 4mm)
See Below
MP6532GF**
TSSOP-28 EP
See Below
* For Tape & Reel, add suffix –Z (e.g. MP6532GR–Z)
** For Tape & Reel, add suffix –Z (e.g. MP6532GF–Z)
TOP MARKING (MP6532GR)
MPS: MPS prefix:
Y: year code;
WW: week code:
MP6532: part number;
LLLLLL: lot number;
TOP MARKING (MP6532GF)
MPS: MPS prefix:
YY: year code;
WW: week code:
MP6532: part number;
LLLLLLLLL: lot number;
MP6532 Rev. 1.23
8/9/2018
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2
MP6532 – 5V TO 60V, THREE PHASE BLDC MOTOR PRE-DRIVER
PACKAGE REFERENCE
22 PWM
VREG
1
28
CPB
BSTA
2
27
CPA
SHA
3
26
VIN
GHA
4
25
GND
DT
VIN
1
21
nBRAKE
GLA
5
24
CPA
2
20
HA
BSTB
6
23
OCREF
CPB
3
19
HB
SHB
7
22
nSLEEP
VREG
4
18
HC
GHB
8
21
nFAULT
GLB
9
20
DIR
BSTC
10
19
PWM
SHC
11
18
nBRAKE
GHC
12
17
HA
14
23 DIR
TOP VIEW
GLC
13
16
HB
SHC
24 nFAULT
nSLEEP
25
26 OCREF
DT
27
28
GND
TOP VIEW
LSS
14
15
HC
MP6532
16
GLC
GHA
7
15
GHC
BSTC
GLB
SHB
GHB
BSTB
GLA
EXPOSED PAD ON
BACKSIDE
CONNECTED TO GND
13
6
12
SHA
11
LSS
10
17
9
5
8
BSTA
QFN-28 (4mm×4mm)
MP6532
EXPOSED PAD ON
BACKSIDE
CONNECTED TO GND
TSSOP-28 EP
ABSOLUTE MAXIMUM RATINGS (1)
Recommended Operating Conditions
Input Voltage VIN ............................ -0.3V to 65V
CPA ............................................... -0.3V to 60V
CPB ............................................ -0.3V to 12.5V
VREG ............................................ -0.3V to 13V
BSTA/B/C ...................................... -0.3V to 70V
GHA/B/C ........................................ -0.3V to 70V
GHA/B/C (Transient, 2μS) ................ -8V to 70V
SHA/B/C ........................................ -0.3V to 65V
SHA/B/C (Transient, 2μS) ................. -8V to 65V
GLA/B/C ........................................ -0.3V to 13V
LSS.................................................. -0.3V to 1V
All Other Pins to AGND................. -0.3V to 6.5V
(2)
Continuous Power Dissipation (TA = +25°C)
QFN-28 (4mm x 4mm)…………………… 2.9W
TSSOP-28 EP ...........................................3.9W
Storage Temperature ............... -55C to +150C
Junction Temperature ............................ +150C
Lead Temperature (Solder) .................... +260C
ESD (Human Body Model)……………….1500V
Input Voltage VIN ................................ 5V to 60V
OCREF Voltage VOC ................... 0.125V to 2.4V
Operating Junct. Temp (TJ)...... -40C to +125C
MP6532 Rev. 1.23
8/9/2018
Thermal Resistance
(4)
θJA
(3)
θJC
QFN-28 (4mm×4mm) ............. 42 ....... 9 .... °C/W
TSSOP-28 EP ........................ 32 ....... 6 .... °C/W
Notes:
1) Exceeding these ratings may damage the device.
2) The maximum allowable power dissipation is a function of the
maximum junction temperature TJ (MAX), the junction-toambient thermal resistance θJA, and the ambient temperature
TA. The maximum allowable continuous power dissipation at
any ambient temperature is calculated by PD (MAX) = (TJ
(MAX)-TA)/θJA. Exceeding the maximum allowable power
dissipation will cause excessive die temperature, and the
regulator will go into thermal shutdown. Internal thermal
shutdown circuitry protects the device from permanent
damage.
3) The device is not guaranteed to function outside of its
operating conditions.
4) Measured on JESD51-7, 4-layer PCB.
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3
MP6532 – 5V TO 60V, THREE PHASE BLDC MOTOR PRE-DRIVER
ELECTRICAL CHARACTERISTICS
VIN = 24V, TA = 25°C, unless otherwise noted.
Parameter
Power Supply
Input Supply Voltage
Quiescent Current
Control Logic
Input Logic ‘Low’ Threshold
Input Logic ‘High’ Threshold
Logic Input Current
Symbol
VIN
IQ
ISLEEP
VIL
VIH
IIN(H)
IIN(L)
ISLEEP-PD
nSLEEP Pull Down Current
Internal Pull Down
RPD
Resistance
nFAULT Output (Open-Drain Output)
Output Low Voltage
VOL
IOH
Output High Leakage Current
Protection Circuits
VIN_RISE
UVLO Rising Threshold
VIN_HYS
UVLO Hysteresis
V
VREG Rising Threshold
REG_RISE
VREG_HYS
VREG Hysteresis
VREG Startup Delay
Short-Circuit Threshold
Accuracy (MOSFET VDS)
OCP Deglitch Time
SLEEP Wakeup Time
LSS Current Limit Threshold
LSS Current Limit Fixed Off
Time
LSS Current Limit High side
Minimum On Time
Thermal Shutdown
MP6532 Rev. 1.23
8/9/2018
Condition
Min
Typ
Max
Units
0.95
60
2
1
V
mA
µA
0.8
1
V
V
µA
µA
µA
880
kΩ
5
nSLEEP=1, gate not switching
nSLEEP=0
VIH=5V
VIL=0.8V
2
-20
-20
All logic inputs except nSLEEP
20
20
IO=5mA
VO=3.3V
3.3
tSLEEP
VLSS
0.4
3.9
200
7.6
0.54
700
1
2.4
3
1
0.5
tOFF
53
66
6.8
tREG
VSC
VOC=1V, TJ =25°C
VOC=2.4V, TJ =25°C
0.8
2.18
tOC
tON
TTSD
1
150
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0.5
1
V
µA
4.5
0.6
V
mV
V
V
µs
V
V
µs
ms
V
80
us
8.4
1
1.2
2.62
us
o
C
4
MP6532 – 5V TO 60V, THREE PHASE BLDC MOTOR PRE-DRIVER
ELECTRICAL CHARACTERISTICS (continued)
VIN = 24V, TA = 25°C, unless otherwise noted.
Parameter
Gate Drive
Bootstrap Diode Forward
Voltage
VREG Output Voltage
Maximum source current
Maximum sink current
Gate Drive Pull Up
Resistance
HS Gate Drive Pull Down
Resistance
LS Gate Drive Pull Down
Resistance
LS Passive Pull Down
Resistance
LS Automatic Turn On Time
Charge Pump Frequency
Dead Time
Symbol
VFBOOT
VREG
(5)
Condition
ID=10mA
ID=100mA
VIN=5.5V-60V,
TJ =25°C
VIN=5V
Min
10
Typ
11.5
Max
Units
0.9
1.3
V
V
12.8
2xVIN-1
IOSO
(5)
IOSI
V
0.8
A
1
A
8
Ω
RUP
VDS=1V
RHS-DN
VDS=1V
1.2
4.3
Ω
RLS-DN
VDS=1V
1
5
Ω
RLS-PDN
tLS
At each commutation time
fCP
tDEAD
DT Open
RDT=200kΩ
DT tied to GND
590
kΩ
1.8
110
6
0.74
30
µs
kHz
µs
µs
ns
NOTE:
5) Guaranteed by design – not tested in production
MP6532 Rev. 1.23
8/9/2018
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5
MP6532 – 5V TO 60V, THREE PHASE BLDC MOTOR PRE-DRIVER
TYPICAL CHARACTERISTICS
MP6532 Rev. 1.23
8/9/2018
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6
MP6532 – 5V TO 60V, THREE PHASE BLDC MOTOR PRE-DRIVER
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 24V, OCREF = 0.5V, RDT = 200k, DIR = H, HA = HC = H, HB = L, fPWM = 20kHz, TA = 25°C,
Resistor+Inductor Load: 5ohm+1mH/phase with star connection, unless otherwise noted.
MP6532 Rev. 1.23
8/9/2018
www.MonolithicPower.com
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7
MP6532 – 5V TO 60V, THREE PHASE BLDC MOTOR PRE-DRIVER
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN = 24V, OCREF = 0.5V, RDT = 200k, DIR = H, HA = HC = H, HB = L, fPWM = 20kHz, TA = 25°C,
Resistor+Inductor Load: 5ohm+1mH/phase with star connection, unless otherwise noted.
MP6532 Rev. 1.23
8/9/2018
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8
MP6532 – 5V TO 60V, THREE PHASE BLDC MOTOR PRE-DRIVER
PIN FUNCTIONS
QFN
Pin #
TSSOP
Pin #
Name
1
26
VIN
2
3
27
28
CPA
CPB
4
1
VREG
5
2
BSTA
6
7
8
3
4
5
SHA
GHA
GLA
9
6
BSTB
10
11
12
7
8
9
SHB
GHB
GLB
13
10
BSTC
14
15
16
17
18
19
20
11
12
13
14
15
16
17
SHC
GHC
GLC
LSS
HC
HB
HA
21
18
nBRAKE
22
19
PWM
23
20
DIR
24
21
nFAULT
25
22
nSLEEP
26
23
OCREF
27
24
DT
28
25
GND
MP6532 Rev. 1.23
8/9/2018
Description
Input supply voltage. Bypass to ground with a ceramic capacitor. Additional
bulk capacitance may be required. See Applications Information section.
Charge pump capacitor. Connect a ceramic capacitor between these pins.
See Applications Information section.
Gate drive supply output. Connect a ceramic capacitor to ground.
See Applications Information section.
Bootstrap phase A. Connect a ceramic capacitor to SHA.
See Applications Information section.
High-side source connection phase A.
High-side gate drive phase A.
Low-side gate drive phase A.
Bootstrap phase B. Connect a ceramic capacitor to SHB.
See Applications Information section.
High-side source connection phase B.
High-side gate drive phase B.
Low-side gate drive phase B.
Bootstrap phase C. Connect a ceramic capacitor to SHC.
See Applications Information section.
High-side source connection phase C.
High-side gate drive phase C.
Low-side gate drive phase C.
Low-side source connection.
Hall-sensor input, phase C. Internal pulldown.
Hall-sensor input, phase B. Internal pulldown.
Hall-sensor input, phase A. Internal pulldown.
Brake input. Active low input turns on all low-side MOFSFETs to brake motor;
high for normal operation. Internal pulldown.
External PWM input.
When active high, the phase selected by the
commutation logic is driven high; when low, the phase is low. Internal pulldown.
Direction input. High or low sets the motor rotation direction. Refer to
commutation table for details.
Fault indication. Open-drain output. nFAULT is logic low when in a fault
condition.
Sleep mode input. Logic low to enter low-power sleep mode; high to enable.
Internal pulldown.
Over-current protection reference voltage input.
Dead time setting. Connect a resistor to ground to set the dead time.
See Applications Information section.
Ground.
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9
MP6532 – 5V TO 60V, THREE PHASE BLDC MOTOR PRE-DRIVER
BLOCK DIAGRAM
CPB
CPA
nSLEEP
DIR
PWM
nBRAKE
HA
HB
HC
VIN
VIN
Charge
Pump
Timing and
Control
Logic
VREG
Trickle
Charge
BSTA
HS Gate
Drive
DT
Phase A,
repeat for
B&C
GHA
SHA
RDT
VREG
TSD
UVLO
VIN
VREG
LS Gate
Drive
SC
Comparator
nFAULT
OCREF
Fault
Handling
LSS
VDS
Monitor
GND
VIN
OCP
Comparator
GLA
RSENSE
0.5V
Figure 1: Functional Block Diagram
MP6532 Rev. 1.23
8/9/2018
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10
MP6532 – 5V TO 60V, THREE PHASE BLDC MOTOR PRE-DRIVER
OPERATION
The MP6532 is a three-phase BLDC motor predriver with built-in commutation logic that drives
three external N-channel MOSFET half bridges,
with 0.8A source and 1A sink current capability. It
operates over a wide input voltage range of 5V to
60V, generating a boosted gate drive voltage
when the input supply is below 12V. The MP6532
features a low-power sleep mode, which disables
the device and draws a very low supply current.
The MP6532 provides several flexible functions,
such as adjustable dead-time control and overcurrent protection, which allow the device to
cover a wide range of applications.
Power-Up Sequence
The power-up sequence is initiated by the
application of voltage to VIN pin. To initiate
power-up, VIN must be above the undervoltage
lockout threshold VUVLO.
After power-up begins, the VREG supply starts
operating. VREG must rise above VREG_RISE
before the device becomes functional.
Refer to the applications information section for
details on the selection of external components.
Sleep Mode (nSLEEP Input)
Driving nSLEEP low will put the device into a
low-power sleep state. In this state, all the
internal circuits are disabled. All inputs are
ignored when nSLEEP is active low. nSLEEP
has an interval pulldown, so it must be driven
high for the device to operate.
When exiting sleep mode, the power-up
sequence described above is repeated.
Input Logic
The PWM input is typically connected to a PWM
signal that controls the speed of the motor. DIR
controls the direction of rotation. nBRAKE, when
active low, turns on all low-side MOSFETs to
stop the motor. This logic is shown in Table 1
below.
Table 1: Input Logic Truth Table
PWM
nBRAKE
The power-up process takes between 1mS and
2mS, after which the MP6532 will respond to
logic inputs and drive the outputs.
X
L
L
H
Gate Drive Power Supplies
Gate drive voltages are generated from the input
power, VIN. A regulated charge pump doubler
circuit supplies a voltage of approximately 11.5V
at the VREG pin. This voltage is used for the
low-side gate drive supply. The charge pump
requires external capacitors between the CPA
and CPB pins, and from VREG to ground.
H
H
The high side gate drive is generated by a
combination of a bootstrap capacitor and an
internal “trickle” charge pump. Bootstrap
capacitors are charged to the VREG voltage
when the low side MOSFET is turned on. This
charge is then used to drive the high side
MOSFET gate when it is turned on.
To keep the bootstrap capacitors charged and
allow operation at 100% duty cycle, an internal
“trickle” charge pump supplies a small current
(about 5µA) to overcome leakages that would
discharge the bootstrap capacitors.
MP6532 Rev. 1.23
8/9/2018
Operation
Brake – all low-side
FETs on
Selected phase driven
low
Selected phase driven
high
Commutation Logic and Hall Inputs
The commutation logic is driven by three Hallsensor inputs. These inputs are connected to
sensors in the motor that are spaced 120° from
each other. Refer to Table 2 for the commutation
logic.
At each Hall input transition, the phase that will
be driven (high or low, depending on the PWM
input pin) is first driven low for a short period of
time (tLS). This ensures that the bootstrap
capacitor is charged at the beginning of each
commutation cycle. Because of this, even if the
PWM input is held high, each phase will pulse
low before being driven high.
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11
MP6532 – 5V TO 60V, THREE PHASE BLDC MOTOR PRE-DRIVER
Table 2: Commutation Table (nBRAKE=1)
HA
1
1
1
0
0
0
1
1
1
0
0
0
Logic Inputs
HB
HC
0
1
0
0
1
0
1
0
1
1
0
1
0
1
0
0
1
0
1
0
1
1
0
1
DIR
1
1
1
1
1
1
0
0
0
0
0
0
GLA
/PWM
0
1
1
0
/PWM
1
0
/PWM
/PWM
0
1
GLB
0
/PWM
/PWM
0
1
1
0
1
1
0
/PWM
/PWM
Driver Outputs
GLC
GHA
1
PWM
1
0
0
0
/PWM
0
/PWM
0
0
PWM
/PWM
0
/PWM
0
0
PWM
1
PWM
1
0
0
0
GHB
0
PWM
PWM
0
0
0
0
0
0
0
PWM
PWM
GHC
0
0
0
PWM
PWM
0
PWM
PWM
0
0
0
0
Motor Terminals
SHA
SHB
SHC
H
Z
L
Z
H
L
L
H
Z
L
Z
H
Z
L
H
H
L
Z
L
Z
H
Z
L
H
H
L
Z
H
Z
L
Z
H
L
L
H
Z
Note: If nBRAKE=0, the braking function would be active, all low-side gates on.
nFAULT
The nFAULT output pin reports to the system
when a fault condition (such as overcurrent or
overtemperature) is detected. nFAULT is an
open-drain output, and it is driven low when a
fault condition occurs. If the fault condition is
released, nFAULT is pulled high by an external
pullup resistor.
Short Circuit Protection (VDS Sensing)
To protect the power stage from damage due to
high currents, a VDS sensing circuitry is
implemented in the MP6532. The voltage drop
across each MOSFET is sensed. (This voltage is
proportional to the RDS-ON of the MOSFET and
the IDS current passing through it). If this voltage
exceeds the voltage supplied to the OCREF
terminal, a short circuit is recognized.
In the event of a short circuit, the MP6532
disables all of the gate drive outputs. nFAULT is
driven active low. The device will stay latched off
until it is reset by nSLEEP or VIN UVLO.
Short circuit protection can be disabled by
connection a 100kΩ resistor from VREG to the
OCREF pin.
Over-current Protection (OCP)
The MP6532 can implement output overcurrent
protection (OCP) by monitoring the current
through a low-side shunt resistor connected to
the low-side MOSFETs. This resistor is
connected to the LSS input pin and the low-side
MOSFET source terminals. If the OCP function is
not desired, the LSS pin and MOSFET source
MP6532 Rev. 1.23
8/9/2018
terminals should all be connected directly to
ground.
If the LSS voltage (the voltage across the shunt
resistor) exceeds the LSS OCP threshold voltage
VLSS-OCP, the high side will turn off and the
corresponding low side turns on for a fixed off
time (tOFF). After the fixed off time, the high side
will turn back on and the cycle repeats until LSS
no longer exceeds the current limit threshold.
The OCP current limit level is selected by the
value of the current sense resistor at LSS pin.
Refer to the applications information section for
more information.
OCP can be used to limit the stall current of a
BLDC motor.
OCP protection can be disabled by connection a
100kΩ resistor from VREG to the OCREF pin.
Short-circuit and OCP Deglitch Time
There is often a current spike during switching
transitions, due to body diode reverse-recovery
current or the distributed capacitance of the load.
This current spike requires filtering to prevent it
from erroneously triggering OCP. An internal
fixed deglitch time (tOC) blanks the output of the
VDS monitor when the outputs are switched.
Dead Time Adjustment
To prevent shoot-through in any phase of the
bridge, it is necessary to have a dead time (tDEAD)
between a high- or low-side turn-off and the next
complementary turn-on event. The dead time for
all three phases is set by a single dead-time
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12
MP6532 – 5V TO 60V, THREE PHASE BLDC MOTOR PRE-DRIVER
resistor (RDT) between DT and ground with
Equation (1):
tDEAD(nS) = 3.7*R(kΩ)
(1)
If DT is tied directly to ground, an internal
minimum dead time (30ns) will be applied.
Leaving DT open generates approximately a 6µs
dead time.
UVLO Protection
If at any time the voltage on VIN falls below the
undervoltage lockout threshold VIN_RISE, all
circuitry in the device is disabled and the internal
logic will be reset.
Operation will resume with the power-up
sequence when VIN rises above the UVLO
thresholds.
After power-up, if the voltage on VREG drops
below the VREG_RISE threshold, the MP6530 will
enter a latched fault state and disable all
functions. The nFAULT pin will be driven active
low. The device will stay latched off until it is
reset by nSLEEP or VIN UVLO.
Thermal Shutdown
If the die temperature exceeds safe limits, the
MP6532 will enter a latched fault state and
disable all functions. The device will stay latched
off until it is reset by nSLEEP or UVLO.
MP6532 Rev. 1.23
8/9/2018
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13
MP6532 – 5V TO 60V, THREE PHASE BLDC MOTOR PRE-DRIVER
APPLICATIONS INFORMATION
VIN Input Voltage
The VIN pin supplies all power to the device. It
must be properly bypassed with a capacitor to
ground
–
see
below
for
specific
recommendations.
The normal operating range of VIN is between
5V and 60V.
VIN should never be allowed to exceed the
absolute maximum ratings, even in a short term
transient condition, or damage to the device may
result. In some cases – especially where
mechanical energy can turn a motor into a
generator – it may be necessary to use some
form of overvoltage protection, such as a TVS
diode, between VIN and ground.
Component Selection
MOSFET selection
Correctly selecting the power MOSFETs used to
drive a motor is crucial to designing a successful
motor drive.
The first requirement is that the MOSFET must
have a VDS breakdown voltage that is higher
than the supply voltage. It is recommended that
considerable margin – 10-15 volts - be added to
prevent MOSFET damage from transient
voltages that can be caused by parasitic
inductances in the PCB layout and wiring. For
example, for 24V power supply applications,
MOSFETs having a breakdown voltage of 40V60V minimum are recommended. More margin is
desirable in high current applications, as the
transients caused by parasitic inductances may
be larger. Also, there are conditions like
regenerative braking that can inject current back
into the power supply; care must be taken that
this does not cause an increase in the power
supply voltage large enough to damage
components.
The MOSFETs must be able to safely pass the
current needed to run the motor. The highest
current condition, which is normally when the
motor is first started or stalled, needs to be
supported. This is typically called the “stall
current” of the motor.
MP6532 Rev. 1.23
8/9/2018
Related to the current capability of the MOSFET
is the rds(on). This is the resistance of the
MOSFET when it is in the fully “turned on” state.
The MOSFET will dissipate power proportional to
the rds(on) and the motor current: P=I2R. The
rds(on) needs to be selected so that for the
desired motor current, the heat generated in this
power can be safely dissipated. In some cases,
this may require special PCB design
considerations and/or external heatsinks to be
used for the MOSFETs.
Some consideration should be made for the safe
operating area (SOA) of the MOSFETs in fault
conditions, such as a short circuit. The IC will act
quickly in the event of a short, but there is still a
very short time (on the order of 3µS) where large
currents can flow in the MOSFETs while the
protection circuits recognize the fault and disable
the outputs.
External Capacitor Selection
The MP6532 has a unique feature in that it can
provide a gate drive voltage (VREG) of 10-12V
even if the input supply voltage drops as low as
5V. This gate drive voltage is generated by a
charge pump inside the part, which uses external
capacitors.
The charge pump flying capacitor, CCP, should
have a capacitance of 470nF. It needs to be
rated to withstand the maximum VIN power
supply voltage. An X7R or X5R ceramic capacitor
is recommended. With a 470nF capacitor, VREG
can output approximately 10mA when VIN is 5V.
If operation below 10V is not needed, a 220nF
capacitor can be used
To provide the large peak currents needed to
turn on the HS MOSFET, bootstrap capacitors
are used. These capacitors are charged when
the output is driven low, then the charge in the
bootstrap capacitor is used to turn on the HS
MOSFET when the output is driven high. (Note
that an internal charge pump will keep the
bootstrap capacitor changed when the output is
held high for an extended period).
The bootstrap capacitors are selected depending
on the MOSFET total gate charge. When the HS
MOSFET is turned on, the charge stored in the
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MP6532 – 5V TO 60V, THREE PHASE BLDC MOTOR PRE-DRIVER
bootstrap capacitor is transferred to the HS
MOSFET gate. As a simplified approximation, the
minimum bootstrap capacitance can be
estimated as CBOOT > 8*QG, where QG is the total
gate charge of the MOSFET in nC, and CBOOT is
in nF. The bootstrap capacitors should not
exceed 1µF, or they may cause improper
operation at start-up.
For most applications, bootstrap capacitors
between 0.1µF and 1µF, X5R or X7R ceramic,
rated for 25V minimum, are recommended.
The VREG pin requires a bypass capacitor to
ground of 10µF. This should be an X7R or X5R
ceramic capacitor rated for 16V minimum.
VIN requires a bypass capacitor to ground,
placed as close as possible to the device. At a
minimum, a 0.1µF X5R or X7R ceramic capacitor,
rated for the VIN voltage, is recommended.
Because of this, it is desirable to minimize the
dead time. However, the dead time must be
made large enough to guarantee under all
conditions that the HS and LS MOSFETs are
never turned on at the same time.
Dead time can be set over a large range, by
selecting the value of the external resistor that is
connected to the DT pin. Usually, a good starting
point is a dead time of about 1µS, which requires
a 200k resistor on the DT pin. If faster switching
and/or a high PWM frequency (over ~30kHz) is
used, shorter dead time may be desirable; if
switching is slowed using external gate resistors,
longer dead time may be needed.
The waveform below shows about a 300nS dead
time between the LS gate turn-off and the HS
gate turn-on.
Depending on the power supply impedance and
the distance between the MOSFETs and the
power supply, additional bulk capacitance is
usually needed. Between 47µF and 470µF of low
ESR electrolytic capacitors are typically used.
Dead Time Resistor Selection
During the transition between driving an output
low and high, there is a short period when neither
the HS nor LS MOSFET is turned on. This period,
called “dead time”, is needed to prevent any
overlap in conduction between HS and LS
MOSFETs, which would effectively provide a
short-circuit directly between the power supply
and ground. This condition, referred to as “shootthrough”, causes large transient currents, and
can destroy the MOSFETs.
Since motors are inductive by nature, once
current is flowing in the motor, it cannot stop
immediately, even if the MOSFETs are turned off.
This “recirculation current” continues to flow in
the original direction until the magnetic field has
decayed.
When the MOSFETs are turned off, this current
will flow through the “body diode” which is
inherent in the MOSFET device.
MOSFET body diodes have a much higher
voltage drop than the MOSFET has during
conduction, so there more power dissipated in
body diode conduction than during the on time.
MP6532 Rev. 1.23
8/9/2018
LSS Resistor Selection
If the voltage applied to the LSS pin ever
exceeds 500mV, an overcurrent event will be
recognized. The external sense resistor is sized
to provide less than 500mV drop at the maximum
expected motor current. For example, if a 50 mΩ
resistor is used, a current of 10 amps would
cause a 500mV drop, and activate the
overcurrent protection.
If this function is not needed, connect LSS
directly to ground.
OCREF Voltage Selection
An internal comparator compares the voltage
drop across each MOSFET with a voltage that is
externally provided on the OCREF input pin.
This voltage is normally provided by an external
resistor divider from a convenient power supply.
If the drop across any MOSFET ever exceeds
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15
MP6532 – 5V TO 60V, THREE PHASE BLDC MOTOR PRE-DRIVER
the voltage on the OCREF pin, a short-circuit
event is recognized.
If this function is not needed, connect OCREF to
VREG through a 100k resistor.
Gate Drive Considerations
The gate characteristics of the selected
MOSFETs will affect how fast they will be
switched and off. The gate drive outputs of the
device can be connected directly to the gates of
the power MOSFETs, which results in the fastest
possible turn-on and turn-off times. However, it
may be advantageous to add external
components (resistors and/or diodes) to modify
the MOSFET turn-on and turn-off characteristics.
Adding external series resistance – typically
between 10 and 100 ohms – will limit the current
that charges and discharges the gate of the
MOSFET, which will slow down the turn-on and
turn-off times. Sometimes this is desirable to
control EMI and noise. Slowing the transition
down too much, however, results in large power
dissipation in the MOSFET during switching.
In some cases, it is desirable to have a slow turnon, but a fast turn-off. This can be implemented
by using a series resistor in parallel with a diode.
At turn-on, the resistor limits the current flow into
the gate; at turn-off, the gate is discharged
quickly through the diode.
1N4148
RGHS
1N4148
This waveform shows the effect of adding a
100Ω series resistor between the GLA and GLH
pins and the MOSFET gates. Rise time on the
phase node has been slowed significantly. The
scale here is 200nS/div.
This waveform shows the effect of adding a
1N4148 diode in parallel with the 100Ω resistors
(with the cathode connected to the IC). You can
see that the fall time of the LS gate is quite fast
compared to the HS gate rise time. The phase
node moves even slower, because of a longer
period of time between when the LS FET is
turned off, and the HS FET is turned on.
RGLS
This waveform below shows the gates of the LS
and HS MOSFETs, and the phase node (output)
with no series resistance. You can see that the
gates transition quickly. The resulting rise time on
the phase node is quite fast. Note the scale of
100nS/div.
MP6532 Rev. 1.23
8/9/2018
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MP6532 – 5V TO 60V, THREE PHASE BLDC MOTOR PRE-DRIVER
PCB Layout
Proper PCB layout is critical to the performance
of MOSFET gate drivers. In particular, the
connection between the HS source and LS drain
needs to be as direct as possible, to avoid
negative undershoot on the phase node due to
parasitic inductances. The pre-driver is designed
to accommodate negative undershoot, but if it is
excessive, unpredictable operation or damage to
the IC can result.
An example PCB layout is shown below. It uses
surface mount N-channel MOSFETs, which
allows very short connection between the HS and
MP6532 Rev. 1.23
8/9/2018
LS MOSFETs. You can also see the use of wide
copper areas for all of the high current paths.
The low-side sense resistor is composed of three
resistors in parallel (R25, R26, and R27), and is
connected to the input supply and LS MOSFET
source terminals by wide copper areas.
Note the location of the charge pump and supply
bypass capacitors, very close to the IC. The
grounded side of these capacitors is connected
to a ground plane, which is connected to the
device ground pin and exposed pad. The highcurrent ground path between the input supply,
input bulk capacitor C19, and MOSFETs is kept
away from this area.
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17
MP6532 – 5V TO 60V, THREE PHASE BLDC MOTOR PRE-DRIVER
PACKAGE INFORMATION
QFN-28 (4mm × 4mm)
PIN 1 ID
SEE DETAIL A
PIN 1 ID
MARKING
PIN 1 ID INDEX
AREA
BOTTOM VIEW
TOP VIEW
PIN 1 ID OPTION A
0.30x45° TYP.
SIDE VIEW
PIN 1 ID OPTION B
R0.25 TYP.
DETAIL A
NOTE:
1) ALL DIMENSIONS ARE IN MILLIMETERS.
2) EXPOSED PADDLE SIZE DOES NOT INCLUDE
MOLD FLASH.
3) LEAD COPLANARITY SHALL BE 0.10 MILLIMETERS
MAX.
4) DRAWING CONFORMS TO JEDEC MO-220.
5) DRAWING IS NOT TO SCALE.
RECOMMENDED LAND PATTERN
MP6532 Rev. 1.23
8/9/2018
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MP6532 – 5V TO 60V, THREE PHASE BLDC MOTOR PRE-DRIVER
PACKAGE INFORMATION
TSSOP-28 EP
NOTICE: The information in this document is subject to change without notice. Users should warrant and guarantee that third
party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not
assume any legal responsibility for any said applications.
MP6532 Rev. 1.23
8/9/2018
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