ALLEGRO A3932SEQ-T

Data Sheet
26301.101d
3932
THREE-PHASE POWER
MOSFET CONTROLLER
23
19
DIR
SA
12
22
H2
GHA
13
21
H3
continued ...
REF
11
30
GLA
DEAD
BRAKE
31
24
AGND
10
32
CB
PGND
SR
1
25
RESET
9
2
GHB
GLC
TACH
3
26
SC
8
4
SB
The A3932SEQ is a three-phase MOSFET controller for use with bipolar brushless dc motors. Its high gate-current drive capability allows
driving a wide range of n-channel power MOSFETs and can support
motor supply voltages to 50 V. Bootstrapped high-side drive blocks
provide the floating positive supplies for the gate drive and minimize
the component count normally required. The high-side circuitry also
employs a unique FET monitoring circuit that ensures the gate voltages
are at the proper levels before turn-on and during the ON cycle.
Internal fixed off-time PWM current-control circuitry can be used to
regulate the maximum load current to a desired value. The peak loadcurrent limit is set by the user’s selection of an input reference voltage
and external sensing resistor. The fixed off-time pulse duration is set by
a user-selected external RC timing network. For added flexibility, the
5
29
SENSE
CC
6
28
RC
GLB
7
27
PWM
FAULT
CONTROL LOGIC
GHC
H1 20
18
MODE
VBB 19
17
FAULT
LCAP 16
VREG 15
CA
14
FEATURES AND BENEFITS
Dwg. PP-068-1
ABSOLUTE MAXIMUM RATINGS
at TA = 25°C
Supply Voltage, VBB .............................. 50 V
Peak Regulator Voltage, VREG ............... 15 V
Logic Input Voltage Range,
VIN ................... -0.3 V to VLCAP + 0.3 V
Sense Voltage Range,
VSENSE ............................ -5 V to +1.5 V
Output Voltage Range,
VSA, VSB, VSC .................. -5 V to +50 V
VGHA, VGHB, VGHC .. -5 V to VBB + 17 V
VCA, VCB, VCC ..................... VSX + 17 V
Operating Temperature Range,
TA .................................. -20°C to +85°C
Junction Temperature, TJ .................. +150°C
Storage Temperature Range,
TS ............................... -55°C to +150°C
■
■
■
■
■
■
■
■
■
■
■
■
■
■
■
■
Drives Wide Range of N-Channel MOSFETs
Synchronous Rectification
Power MOSFET Protection
Adjustable Dead Time for Cross-Conduction Protection
100% Duty Cycle Operation
Selectable Fast or Slow Current-Decay Modes
Internal PWM Peak Current Control
High-Current Gate Drive
Motor Lead Short-to-Ground Protection
Internal 5-V Regulator
Brake Input
PWM Torque-Control Input
Fault-Diagnostic Output
Tachometer Output
Thermal Shutdown
Undervoltage Protection
3932
THREE-PHASE POWER
MOSFET CONTROLLER
Selection Guide
Part Number
Pb-Free*
Packing
A3932SEQ-T
Yes
32 pieces/tube
A3932SEQTR-T
Yes
13-in. reel, 800 pieces/reel
*Pb-based variants are being phased out of the product line. The variants cited in this footnote are in production but
have been determined to be NOT FOR NEW DESIGN. This classification indicates that sale of this device is currently
restricted to existing customer applications. The variants should not be purchased for new design applications because
obsolescence in the near future is probable. Samples are no longer available. Status change: May 1, 2006. These
variants include: A3932SEQ adn A3932SEQTR.
www.allegromicro.com
2
3932
THREE-PHASE POWER
MOSFET CONTROLLER
Functional Block Diagram
NOTE — For 12 V applications, VBB is shorted to VREG.
The VREG absolute maximum rating (15 V) must not be
exceeded.
PWM input can be used to provide speed/torque control,
allowing the internal current control circuit to set the maximum current limit.
Optional synchronous rectification is included. This
feature will short out the current path through the power
MOSFETs’ reverse body diodes during the PWM off-cycle
current decay. This can minimize power dissipation in the
power MOSFETs, eliminate the need for external power
clamp diodes, and potentially allow a more economical
choice for the MOSFET drivers.
2
The A3932 includes the commutation logic for Hall sensors configured for 120 degree spacing. Power MOSFET
protection features include bootstrap capacitor charging
current monitor, undervoltage monitor, motor-lead shortto-ground, and thermal shutdown.
The ‘–S–’ part-number suffix indicates an operating
temperature range of -20°C to +85°C. The ‘–EQ–’ suffix
indicates a 32-lead rectangular plastic chip carrier (PLCC).
The initial ‘–TR–’ variant suffix indicates tape and reel
packing. The ‘–T’ final variant suffix indicates lead (Pb)
free composition, with 100% matte tin leadframe plating.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 2002, 2003 Allegro MicroSystems, Inc.
3932
THREE-PHASE POWER
MOSFET CONTROLLER
ELECTRICAL CHARACTERISTICS: unless otherwise noted at TA = 25°C; VBB = 18 V to 50 V; CLCAP,
Cboot = 0.1 µF; CREG = 10 µF; Cload = 3300 pF; fPWM = 22.5 kHz Square Wave; Two Phases Active.
Limits
Parameter
Symbol
Conditions
Min
Typ
Max
Units
–
–
8.0
mA
Supply Current
RESET high, coast mode, stopped
Quiescent Current
IBB
Reference Voltage
VLCAP
ILCAP = -3 mA
4.75
5.0
5.25
V
Output Voltage
VREG
VBB = VREG ≤15 V, IREG = -10 mA
10.8
–
13.2
V
18 V ≤ VBB ≤ 50 V, IREG = -10 mA
12.4
13
13.6
V
–
VBB - 2.5
–
V
∆VREG(∆IREG) IREG = -1 to -30 mA, coast
–
25
–
mV
∆VREG(∆VBB)
IREG = -10 mA, coast
–
40
–
mV
VIH
All inputs except SR
2.0
–
–
V
SR input only
3.0
–
–
V
All inputs except SR
–
–
0.8
V
SR input only
–
–
1.8
V
VBB = 13.2 V to 18 V, IREG = -10 mA
Output Voltage Regulation
Digital Logic Levels
Logic Input Voltage
VIL
Logic Input Current
IIH
VIH = 2 V
-30
–
-90
µA
IIL
VIL = 0.8 V
-50
–
-130
µA
–
V
Gate Drive
Low-Side Output Voltage
VGLxH
IGLx = 0
High-Side Output Voltage
VGHxH
IGHx = 0
Pulldown Switch Resistance
rDS(on)
Pullup Switch Resistance
rDS(on)
VREG - 0.8 VREG - 0.5
10.4
11.6
12.8
V
IGLx = 50 mA
–
4.0
–
Ω
IGHx = -50 mA
–
14
–
Ω
Low-Side Output
Switching Time
trGLx
10% to 90%, with Cload
–
120
–
ns
tfGLx
90% to 10%, with Cload
–
60
–
ns
High-Side Output
Switching Time
trGHx
10% to 90%, with Cload
–
120
–
ns
tfGHx
90% to 10%, with Cload
–
60
–
ns
tpr
GHx, GLx rising, Cload = 0
–
220
–
ns
tpf
GHx, GLx falling, Cload = 0
–
110
–
ns
Propagation Delay Time
(PWM to gate output)
Maximum Dead Time
tdead
GHx to GLx, VDEAD = 0 V, Cload = 0
3.5
5.6
7.6
µs
Minimum Dead Time
tdead
GLx to GHx, IDEAD = 780 µA, Cload = 0
50
100
150
ns
NOTES: 1. Typical Data is for design information only.
2. Negative current is defined as coming out of (sourcing) the specified device terminal.
www.allegromicro.com
Continued —
3
3932
THREE-PHASE POWER
MOSFET CONTROLLER
ELECTRICAL CHARACTERISTICS: unless otherwise noted at TA = 25°C; VBB = 18 V to 50 V; CLCAP,
Cboot = 0.1 µF; CREG = 10 µF; Cload = 3300 pF; fPWM = 22.5 kHz Square Wave; Two Phases Active.
Parameter
Symbol
Conditions
Min
Limits
Typ Max
Units
Bootstrap Capacitor
Bootstrap Charge Current
ICx
100
–
–
mA
Bootstrap Output Voltage
VCx
VSx = 0, ICx = 0, VREG = 13 V
10.4
11.6
12.8
V
Bootstrap Resistance
rCx
ICx = -50 mA
–
9.0
12
Ω
Vio
0 V ≤ VIC ≤ 1.5 V
–
–
±5.0
mV
ISENSE
VIC ≥ 0 V, VID ≤ 1.5 V
–
-25
–
µA
REFERENCE Input Current
IREF
VIC ≥ 0 V, VID ≤ 1.5 V
–
0
–
µA
Blank Time
tblank
RT = 56 kΩ, CT = 470 pF
–
0.91
–
µs
IRC
-0.9
-1.0
-1.1
mA
VRCL
1.0
1.1
1.2
V
VRCH
2.7
3.0
3.3
V
Bootstrap Charge Threshold
ICx
–
-9.0
–
mA
Motor Short-to-Ground Monitor
VDSH
VBB - VSX, high side on
1.3
2.0
2.7
V
Undervoltage Threshold
UVLO
Increasing VREG
9.2
9.7
10.2
V
Decreasing VREG
8.6
9.1
9.6
V
Current Limit Circuitry
Input Offset Voltage
SENSE Input Current
RC Charge Current
RC Voltage Threshold
Protection Circuitry
FAULT Output Voltage
VFAULT
IO = 1 mA
–
–
0.5
V
TACH Output Voltage
VTACH
IO = 1 mA
–
–
0.5
V
TACH Output Pulse Width
tTACH
IO = 1 mA, CTACH = 50 pF
–
0.75
–
µs
Thermal Shutdown Temp.
TJ
–
165
–
°C
Thermal Shutdown Hysteresis
∆TJ
–
10
–
°C
Thermal Resistance
RθJA
–
37
–
°C/W
High K board per JEDEC JESD51-7
NOTES: 1.Typical Data is for design information only.
2.Negative current is defined as coming out of (sourcing) the specified device terminal.
4
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
3932
THREE-PHASE POWER
MOSFET CONTROLLER
Terminal Descriptions
Terminal
Name
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
PGND
RESET
GLC
SC
GHC
CC
GLB
SB
GHB
CB
GLA
SA
GHA
CA
VREG
LCAP
FAULT
MODE
VBB
H1
H3
H2
DIR
BRAKE
SR
TACH
PWM
RC
SENSE
REF
DEAD
32
AGND
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RESET — A logic input used to enable the device, internally
pulled up to VLCAP (+5 V). A RESET = 1 will disable the
device and force all gate drivers to 0 V, coasting the motor. A
RESET = 0 allows the gate drive to follow the commutation
logic. The RESET = 1 overrides BRAKE.
GLA/GLB/GLC — Low-side, gate-drive outputs for external
NMOS drivers. External series-gate resistors (as close as
possible to the NMOS gate) can be used to control the slew rate
seen at the power-driver gate, thereby controlling the di/dt and
dv/dt of the SA/SB/SC outputs. GLx = 1 (or “high”) means that
the upper half (PMOS) of the driver is turned on and its drain
will source current to the gate of the low-side FET in the
external motor-driving bridge. GLx = 0 (or “low”) means that
the lower half (NMOS) of the driver is turned on and its drain
will sink current from the external FET’s gate circuit.
SA/SB/SC — Directly connected to the motor, these terminals
sense the voltages switched across the load. These terminals
are also connected to the negative side of the bootstrap capacitors and are the negative supply connections for the floating
high-side drivers.
GHA/GHB/GHC — High-side, gate-drive outputs for external
NMOS drivers. External series-gate resistors can be used to
control the slew rate seen at the power-driver gate, thereby
controlling the di/dt and dv/dt of the SA/SB/SC outputs.
GHx = 1 (or “high”) means that the upper half (PMOS) of the
driver is turned on and its drain will source current to the gate
of the high-side FET in the external motor-driving bridge. GHx
= 0 (or “low”) means that the lower half (NMOS) of the driver
is turned on and its drain will sink current from the external
FET’s gate circuit.
CA/CB/CC — High-side connections for the bootstrap capacitors, positive supply for high-side gate drivers. The bootstrap
capacitors are charged to approximately VREG when the
associated output Sx terminal is low. When the output swings
high, the voltage on this terminal rises with the output to
provide the boosted gate voltage needed for n-channel power
MOSFETs.
continued next page
5
3932
THREE-PHASE POWER
MOSFET CONTROLLER
Terminal Descriptions (cont’d)
FAULT — Open-drain output to indicate fault condition;
FAULT = 1 (external pull-up) for any of the following:
1 – invalid HALL input code,
2 – undervoltage condition detected at VREG.
3 – thermal shutdown, or
4 – motor lead (SA/SB/SC) shorted to ground.
Except for a short-to-ground fault that only turns off the
high-side drivers, faults will force a coast condition that turns
off all power MOSFETs. Only the short-to-ground fault is
latched but is cleared at each commutation. If the motor has
stalled due to a short-to-ground being detected, toggling the
RESET terminal or repeating a power-up sequence will clear
the fault. Typically pulled up to VLCAP (+5 V) with an external
5.1 kΩ resistor.
MODE — A logic input to set current-decay method, internally
pulled up to VLCAP (+5 V). When in slow-decay mode (MODE
= 1), only the high-side MOSFET is switched off during a
PWM-off cycle. The fast-decay mode (MODE = 0) switches
both the high-side and low-side MOSFETs.
H1/H2/H3 — Hall-sensor inputs; internally pulled up to VLCAP
(+5 V). Configured for 120° electrical spacing.
DIR — A logic input to reverse rotation, see Commutation
Truth Table. Internally pulled up to VLCAP (+5 V).
BRAKE — An active-low logic input for a braking function. A
BRAKE = 0 will turn on the low-side FETs and turn off the
high-side FETs. This will effectively short-circuit the BEMF in
the windings and brake the motor. The braking torque applied
will depend on the speed. Internally pulled up to VLCAP (+5 V).
RESET = 1 overrides BRAKE and will coast the motor.
SR — Synchronous rectification input. An SR = 0 disables this
feature, forcing current decay through the body diodes of the
power MOSFETs. An SR = 1 will result in appropriate highand low-side gate outputs to switch in response to a PWM-off
command. Internally pulled up to VLCAP (+5 V). See also the
Input Logic table.
TACH — An open-drain digital output whose frequency is
proportional to speed of rotation. A pulse appears at every
HALL transition. Typically pulled up to VLCAP (+5 V) with an
external 5.1 kΩ resistor.
6
PWM — Speed control input, internally pulled up to VLCAP
(+5 V). A PWM = 0 turns off selected drivers. A PWM = 1
will turn on selected drivers as determined by H1/H2/H3 input
logic. Holding PWM = 1 allows speed/torque control solely by
the internal current-limit circuit with the REF analog voltage.
See also the Input Logic table
.
RC — An analog input used to set the fixed off time with an
external resistor (RT) and capacitor (CT). The tblank time is
controlled by the value of the external capacitor (see Applications Information). See Application Information.
SENSE — An analog input to the current-limit comparator.
A voltage representing load current appears on this terminal
during on time, when it reaches REF voltage, the comparator
trips and load current decays for the fixed off-time interval.
Voltage transients seen at this terminal when the drivers turn on
are ignored for time tblank.
REF — An analog input to the current-limit comparator.
Voltage applied here with respect to AGND sets the peak load
current.
Ipeak = VREF/RS.
VREG — A regulated 13 V output; supply for low-side gate
drive and bootstrap capacitor charge circuits. It is good practice
to connect a decoupling capacitor from this terminal to AGND,
as close to the device terminals as possible. This terminal
should be shorted to VBB for 12 V applications.
VBB — The A3932 supply voltage. It is good practice to
connect a decoupling capacitor from this terminal to AGND, as
close to the device terminals as possible.
LCAP — Connection for 0.1 µF decoupling capacitor for the
internal 5 V reference. This terminal can source no more than
3 mA for the DEAD input, TACH and FAULT outputs.
DEAD — An analog input. A resistor between DEAD and
LCAP is selected to adjust the turn-off to turn-on time. This
delay is needed to prevent shoot-through in the external power
MOSFETs. See Applications Information for details on setting
dead time.
AGND — The low-level (analog) reference point.
PGND — The return for all low-side gate drivers. This should
be connected to the system power ground.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
3932
THREE-PHASE POWER
MOSFET CONTROLLER
Commutation Truth Table
Logic Inputs
H2
H3
H1
1
1
1
0
0
0
1
1
1
0
0
0
0
0
1
1
1
0
0
0
1
1
1
0
DIR
GLA
GLB
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
0
0
1
0
0
0
0
1
0
0
0
0
1
1
0
1
1
0
0
0
1
0
0
0
1
1
1
0
0
0
1
1
Driver Outputs
GLC
GHA
1
1
0
0
0
0
0
0
0
1
1
0
1
0
0
0
0
1
0
0
1
1
0
0
GHB
GHC
0
1
1
0
0
0
0
0
0
0
1
1
0
0
0
1
1
0
1
1
0
0
0
0
Motor Terminals
SA
SB
SC
H
Z
L
L
Z
H
L
Z
H
H
Z
L
Z
H
H
Z
L
L
Z
L
L
Z
H
H
L
L
Z
H
H
Z
H
H
Z
L
L
Z
Input Logic
MODE
PWM
SR
RESET
0
0
1
1
0
0
1
1
X
0
1
0
1
0
1
0
1
X
0
0
0
0
1
1
1
1
X
0
0
0
0
0
0
0
0
1
Operation
PWM chop mode, fast decay, all drivers off
Peak current limit, selected drivers on
PWM chop mode. slow decay, selected low side drivers on
Peak current limit, selected drivers on
PWM chop mode, fast decay with opposite of selected drivers on
Peak current limit, selected drivers on
PWM chop, slow decay with both low-side drivers on
Peak current limit, selected drivers on
All gate drive outputs off, clear fault logic, coast
L = Low (less positive) level
H = High (more positive) level
X = Don’t care
Z = High impedance
1 = Active or true logic condition
0 = Inactive or false logic condition
Dwg. OA-007-32
www.allegromicro.com
7
3932
THREE-PHASE POWER
MOSFET CONTROLLER
Applications Information
Synchronous Rectification. To reduce power dissipation
in the external MOSFETs, the A3932 control logic turns on the
appropriate low-side and high-side driver during the loadcurrent recirculation, PWM-off cycle. Synchronous
rectification allows current to flow through the MODE-selected
MOSFET, rather than the body diode, during the decay time.
The body diodes of the SR power MOSFETs will conduct only
during the dead time required at each PWM transition.
Dead Time. It is required to have a dead-time delay between a
high- or low-side turn off and the next turn-on event to prevent
cross conduction. The potential for cross conduction occurs
with synchronous rectification, direction changes, PWM, or
after a bootstrap capacitor charging cycle. The dead time is set
by a resistor (Rdead) between the DEAD terminal and LCAP
(+5 V) and can be set between 100 ns and 5.5 µs.
The following equations are valid for Rdead between 5.6 kΩ
and 470 kΩ. At 25°C,
tdead (nom, ns) = 37 + (11.9 x 10-3 x (Rdead + 500))
For predicting worst case, over voltage and temperature
extremes,
tdead (min, ns) = 10 + (6.55 x 10-3 x (Rdead + 350))
tdead (max, ns) = 63 + (17.2 x 10-3 x (Rdead + 650))
For comparison with IDEAD test currents,
IDEAD = (VLCAP – Vbe)/(Rdead + Rint)
where (nominal values) VLCAP = 5 V, Vbe = 0.7 V at 25°C, and
Rint = 500 Ω.
Rather than use Rdead values near 470 kΩ, set DEAD =
ground (VDEAD = 0 V), which activates an internal (IDEAD =
10 µA) current source.
The choice of power MOSFET and external series gate
resistance determines the selection of the dead-time resistor.
The dead time should be made long enough to cover the
variation of the MOSFET gate capacitance and series gate
resistance (both external and internal to the A3932) tolerances.
Decoupling. The internal reference, VREG, supplies current
for the gate-drive circuit. As the gates are driven high they will
require current from an external capacitor to support the
transients. This capacitor should be placed as close as possible
to the VREG terminal. Its value should be at least 20 times
larger than the bootstrap capacitor.
8
Additionally, a 0.1 µF (or larger) decoupling capacitor
should be connected between LCAP and AGND as close to the
device terminals as possible.
Protection Circuitry. The A3932 has several protection
features:
1) Bootstrap Circuit. The bootstrap capacitor is charged
whenever a low-side MOSFET is on, Sx output goes low, and
the load current recirculates. This happens constantly during
normal operation. The high-side MOSFET will not be allowed
to turn on before the charging has decayed to less than
approximately 9 mA. No fault will be registered.
When a phase’s high-side driver is on for a long time
(100% duty cycle operation) its charge pump is designed to
maintain VGS > 9 V on the bridge FET if IGHx (the load on the
gate driver) < 10 µA.
2) Hall Invalid. Illegal codes for the HALL inputs (000 or
111) will force a fault and coast the motor. Noisy Hall lines
may cause double TACH pulses and, therefore, code errors that
produce faults. Additional external pullup loading and filtering
may be required depending on the system.
3) VREG Undervoltage. An internal regulator supplies the
low-side gate driver and the bootstrap charge current. It is critical
to ensure that VREG is at the proper level before enabling any of
the outputs. The undervoltage circuit is active during power-up
and will force a motor coast condition (all gate drives, GHx and
GLx = 0) until VREG is greater than approximately 9.7 V.
4) Thermal Shutdown. A junction temperature greater than
165°C will signal a fault and coast the motor (all gate drives
LOW). If the junction temperature then falls to less than 155°C
(hysteresis), the fault will be cleared.
5) Motor Lead Shorted to Ground. The A3932 will signal a
fault if a motor lead is shorted to ground. A short to ground is
assumed after a high side is turned on and greater than 2 V is
measured between the drain (VBB) and source (SA/SB/SC) of
the high-side power MOSFET. This fault is cleared at the
beginning of each commutation. If a stalled motor results from
a fault, the fault can only be cleared by toggling the RESET
terminal or by a power-up sequence.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
continued next page
3932
THREE-PHASE POWER
MOSFET CONTROLLER
Applications Information (cont’d)
Current Control. Internal fixed off-time PWM circuitry is
implemented to limit load current to a desired value. When a
high-side and low-side MOSFET are turned on, current will
increase in the motor winding until it reaches a value given by
ITRIP ≈ VREF/RS.
Because the load current does not flow through the sense
resistor during a dynamic brake, care must be taken to ensure
that the power MOSFET’s maximum ratings are not exceeded.
At the trip point, the sense comparator resets the sourceenable latch, turning off the high-side driver. Load
inductance causes the current to recirculate (decay) for the fixed
off time. The current path during recirculation is determined by
the configuration of the MODE and SR inputs.
Low-Voltage Operation. Although VREG can be connected
to VBB for 12 V systems, the VREG maximum rating of 15 V
must be observed including transients. If transients cannot be
adequately controlled, use VREG in the regulator mode (not
connected to VBB). With VBB less than 18 V, the VREG output
voltage level specification may not be met. Note that in this
mode the VREG undervoltage threshold may leave the system
with little headroom if VBB is less than 12 V.
An external resistor (RT) and capacitor (CT), connected in
parallel from the RC terminal to AGND, are used to set the
fixed off-time period (toff = RT x CT). RT should be in the range
of 10 kΩ to 500 kΩ. The toff should be in the range of 10 µs to
50 µs. Larger values for toff can result in audible noise
problems.
Torque control can be implemented by varying the REF
input voltage as long as the PWM input stays high. If direct
control of the torque/current is desired by PWM input, a voltage
can be applied to the REF input to set an absolute maximum
current limit.
RESET = 1 overrides BRAKE and turns all motor bridge
FETs off, coasting the motor.
Driving an H Bridge. The A3932 may be used to drive an H
bridge (e.g., a brush dc motor load) by hard wiring one state for
the Hall inputs (e.g., H1 = H2 = 1 (HIGH), H3 = 0 (LOW)).
Leave the appropriate phase driver outputs floating (in this case
CC, GHC, SC, and GLC because, from the Commutation Truth
Table, SC = Z). The DIR input controls the motor rotation
while the PWM, MODE, and SR inputs control the motor
current behavior as described in the Input Logic table.
PWM Blank. The capacitor (CT) also serves as the means to
set the blank time duration. At the end of the PWM off cycle, a
high-side gate selected by the commutation logic will turn on.
At this time, large current transients can occur during the
reverse recovery time (trr) of the intrinsic body diodes of the
external power MOSFETs. To prevent false tripping of the
current-sense comparator, the blank function disables the
comparator for a time
tblank = 1.9 x CT/(0.001 - [2/RT])
Layout. Careful consideration must be given to PCB layout
when designing high-frequency, fast-switching, high-current
circuits.
The user must ensure that CT is large enough to cover the
current-spike duration.
2) Minimize stray inductances by using short, wide copper
runs at the drain and source terminals of all power MOSFETs.
This includes motor lead connections, the input power buss, and
the common source of the low-side power MOSFETs. This will
minimize voltages induced by fast switching of large load
currents.
Braking. The A3932 will dynamically brake by forcing all
low-side MOSFETs on and all high-side MOSFETs off. This
will effectively short-circuit the BEMF and brake the motor.
During braking, the load current can be approximated by:
IBRAKE = VBEMF/RL
www.allegromicro.com
1) The analog ground (AGND), the power ground (PGND),
and the high-current return of the external MOSFETs (the
negative side of the sense resistor) should return separately to
the negative side of the motor supply filtering capacitor. This
will minimize the effect of switching noise on the device logic
and analog reference.
3) Kelvin connect the SENSE terminal PC trace to the
positive side of the sense resistor.
9
3932
THREE-PHASE POWER
MOSFET CONTROLLER
Dimensions in Inches
(controlling dimensions)
20
0.013
0.021
14
13
21
0.026
0.032
0.546
0.476
0.595
0.585
LONG SIDE
(0.446
0.376
0.553
0.547
SHORT SIDE)
0.050
BSC
29
5
30
32
1
4
0.453
0.447
0.495
0.485
0.015
MIN
0.125
0.140
Dwg. MA-006-32 in
NOTES: 1. Lead spacing tolerance is non-cumulative.
2. Exact body and lead configuration at vendor’s option within limits shown
3. Supplied in standard sticks/tubes of 32 devices or add “TR” to part number for tape and reel.
10
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
3932
THREE-PHASE POWER
MOSFET CONTROLLER
Dimensions in Millimeters
(for reference only)
20
0.33
0.54
14
13
21
0.66
0.82
13.86
12.10
15.11
14.86
LONG SIDE
(11.32
9.56
14.04
13.90
SHORT SIDE)
1.27
BSC
29
5
30
0.38
MIN
3.18
3.55
32
1
4
11.50
11.36
12.57
12.32
Dwg. MA-006-32 mm
NOTES: 1. Lead spacing tolerance is non-cumulative.
2. Exact body and lead configuration at vendor’s option within limits shown
3. Supplied in standard sticks/tubes of 32 devices or add “TR” to part number for tape and reel.
The products described here are manufactured under one or more U.S. patents or U.S.
patents pending.
Allegro MicroSystems, Inc. reserves the right to make, from time to time, such departures
from the detail specifications as may be required to permit improvements in the performance,
reliability, or manufacturability of its products. Before placing an order, the user is cautioned to
verify that the information being relied upon is current.
Allegro products are not authorized for use as critical components in life-support devices or
systems without express written approval.
The information included herein is believed to be accurate and reliable. However, Allegro
MicroSystems, Inc. assumes no responsibility for its use; nor for any infringement of patents or
other rights of third parties which may result from its use.
www.allegromicro.com
11
3932
THREE-PHASE POWER
MOSFET CONTROLLER
MOTOR DRIVERS
Function
Output Ratings*
Part Number†
INTEGRATED CIRCUITS FOR BRUSHLESS DC MOTORS
3-Phase Power MOSFET Controller
—
28 V
3933
3-Phase Power MOSFET Controller
—
40 V
3935
3-Phase Power MOSFET Controller
—
50 V
3932 & 3938
3-Phase Back-EMF Controller/Driver
±900 mA
14 V
8904
3-Phase PWM Current-Controlled DMOS Driver
±3.0 A
50 V
3936
INTEGRATED BRIDGE DRIVERS FOR DC AND BIPOLAR STEPPER MOTORS
PWM Current-Controlled Dual Full Bridge
±500 mA
18 V
3965
Dual Full Bridge with Protection & Diagnostics
±500 mA
30 V
3976
PWM Current-Controlled Dual Full Bridge
±650 mA
30 V
3966
PWM Current-Controlled Dual Full Bridge
±650 mA
30 V
3968
Microstepping Translator/Dual Full Bridge
±750 mA
30 V
3967
PWM Current-Controlled Dual Full Bridge
±750 mA
45 V
2916
PWM Current-Controlled Dual Full Bridge
±750 mA
45 V
2919
PWM Current-Controlled Dual Full Bridge
±750 mA
45 V
6219
PWM Current-Controlled Dual Full Bridge
±800 mA
33 V
3964
PWM Current-Controlled Dual DMOS Full Bridge
±1.0 A
35 V
3973
PWM Current-Controlled Full Bridge
±1.3 A
50 V
3953
PWM Current-Controlled Dual Full Bridge
±1.5 A
45 V
2917
PWM Current-Controlled DMOS Full Bridge
±1.5 A
50 V
3948
PWM Current-Controlled Microstepping Full Bridge
±1.5 A
50 V
3955
PWM Current-Controlled Microstepping Full Bridge
±1.5 A
50 V
3957
PWM Current-Controlled Dual DMOS Full Bridge
±1.5 A
50 V
3972
PWM Current-Controlled Dual DMOS Full Bridge
±1.5 A
50 V
3974
PWM Current-Controlled Full Bridge
±2.0 A
50 V
3952
PWM Current-Controlled DMOS Full Bridge
±2.0 A
50 V
3958
Microstepping Translator/Dual DMOS Full Bridge
±2.5 A
35 V
3977
PWM Current-Controlled DMOS Full Bridge
±3.0 A
50 V
3959
UNIPOLAR STEPPER MOTOR & OTHER DRIVERS
Unipolar Stepper-Motor Translator/Driver
1.25 A
50 V
5804
Unipolar Stepper-Motor Quad Drivers
1.5 A
46 V
7024 & 7029
Unipolar Microstepper-Motor Quad Driver
1.5 A
46 V
7042
Unipolar Stepper-Motor Quad Driver
1.8 A
50 V
2540
Unipolar Stepper-Motor Translator/Driver
2.0 A
46 V
7051
Unipolar Stepper-Motor Quad Driver
3.0 A
46 V
7026
Unipolar Microstepper-Motor Quad Driver
3.0 A
46 V
7044
* Current is maximum specified test condition, voltage is maximum rating. See specification for sustaining voltage limits
or over-current protection voltage limits. Negative current is defined as coming out of (sourcing) the output.
† Complete part number includes additional characters to indicate operating temperature range and package style.
Also, see 3175, 3177, 3235, and 3275 Hall-effect sensors for use with brushless dc motors.
12
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000