Page
1
of
8
3932
The A3932SEQ is a three-phase brushless DC motor controller. The
A3932's high current gate drive capability allows driving of a wide range of
power MOSFETs and can support motor supply voltages from 12 to 50V.
The A3932 integrates a bootstrapped high side driver to minimize the
external component count required to drive N-channel MOSFET drivers.
Internal fixed off time PWM current control circuitry can be used to
regulate the maximum load current to a desired value. The peak load current
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 PWM input can be
used to provide speed/torque control, allowing the internal current control
circuit to set a maximum current limit.
The A3932 includes optional synchronous rectification. This feature
will short out the current path through the power MOSFETs intrinsic body
diodes during PWM off cycle current decay. This can minimize power
dissipation in the MOSFETs, eliminate the need for external power clamp
diodes, and potentially allow a more economical choice for the MOSFET
drivers.
The A3932 provides commutation logic for Hall sensors configured
for 120-degree spacing. The Hall input pins are pulled up to an internally
generated 5V reference. Power MOSFET protection features includes gate-
source voltage monitor, bootstrap capacitor charging current monitor,
undervoltage monitor, motor lead short to supply or ground, and thermal
shutdown.
FEATURES
n
Drives Wide Range of N-channel
MOSFETs
n
Sources 1.25A for Gate Turn-On
n
Sinks 2.5A for Gate Turn-Off
n
Synchronous Rectification
n
Power MOSFET Protection
n
Adjustable Dead Time for Cross
Conduction Protection
n
Fast/Slow Current Decay Modes
n
Internal PWM current Control
n
PWM Torque Control Input
n
Motor Lead Short to Supply
and Ground Protection
n
Internal 5V Regulator
n
Direction Control
n
Brake Input
n
Fault Diagnostic Output
n
Tachometer Output
n
Thermal Shutdown
n
Undervoltage Protection
n
32L PLCC Package
8
7
6
5
10
9
12
26
27
28
29
22
25
24
21
CC
GHC
GLB
SB
GHB
CB
SA
PWM
TACH
SENSE
RC
H3
BRAKE
H2
SR
A3932SEQ
4
SC
11
GLA
13
GHA
23
DIR
3
GLC
2
RESET
1
PGND
32
AGND
31
DEAD
30
REF
14
CA
15
VREG
16
LCAP
17
FAULT
18
MODE
19
V
BB
20
H1
ABSOLUTE MAXIMUM RATINGS
at TA = +25
C
Load Supply Voltage, V
BB
............................ 50 V
VREG
(Transient) ......................................... 15 V
Logic Input Voltage Range,
V
IN
...................-0.3 V to V
LCAP
+ 0.3 V
Sense Voltage, V
SENSE
........................ -5 to 1.5 V
Pins SA/SB/SC, ................................... -5 to 50 V
Pins GHA/GHB/GHC ................-5 to V
BB
+ 17 V
Pins CA/CB/CC .........................SA/SB/SC+17 V
Package Power Dissipation (TA = +25
C)
R
JA
..................................... 52.4
C/W
R
JC
..................................... 22.7
C/W
P
D
................................................ 2.4 W
Operating Temperature Range,
T
A
................................ -20
C to +85
C
Junction Temperature, T
J
......................... +150
C
Storage Temperature Range,
T
S
............................... -55
C to +150
C
ADVANCED DATASHEET - 03/02/99
(Subject to change without notice)
THREE PHASE POWER
MOSFET CONTROLLER
Always order by complete part number: A3932SEQ
Page 2
3932
THREE-PHASE POWER MOSFET CONTROLLER
Functional Block Diagram (1 of 3 outputs shown)
Turn-on
Delay
Control
Logic
VREG
Regulator
VBB
Bootcap
Monitor
Gate-Source
Monitor
Dead-Time
Adjust
Undervoltage
Detect
RC Blanking
Fixed - Off
Time
Turn-on
Delay
VREG
Bootstrap low
Vgs Low
Invalid Hall
Undervoltage
LCAP
High
Side
Driver
Low
Side
Driver
High Side Protection
Logic
CA
GHA
SA
DEAD
GLA
PGND
FAULT
AGND
RC
MODE
SR
PWM
SENSE
To Phase B
REF
-
+
C
BOOT
to LCAP
DIR
RESET
BRAKE
R
T
C
T
To Phase C
H2
H1
H3
TACH
Low Side Protection
Logic
R
S
Motor Lead Short
Page 3
3932
THREE-PHASE POWER MOSFET CONTROLLER
ELECTRICAL CHARACTERISTICS at TA = +25C, V
BB
= 50 V, C
BOOT
= .1f, C
LOAD
=1000pf
(unless noted otherwise)
Characteristics
Symbol
Test Conditions
Min.
Typ.
Max.
Units
Quiescent current
I
VBB
RESET Low
6.5
8.5
mA
I
VBB
RESET High
6.5
mA
LCAP Regulator
V
LCAP
4.75
5
5.250
V
Motor Supply Voltage Range
18
50
V
VREG shorted to V
BB
10.8
13.2
V
VREG Output Voltage
V
REG
12.4
13
13.6
V
VREG Line Regulation
V
REGLIN
V
BB
18 to 50V
40
mV
Control Logic
Logic Input Voltage
V
IN(1)
2.0
V
V
IN(0)
.8
V
Logic Input Current
I
IN(1)
V
IN
= 2.0 V
<1.0
10
A
I
IN(0)
V
IN
= 0.8 V
-70
-130
A
Gate Drive
Low side drive, output high
V
HGL
12.3
13
13.7
V
High side drive, output high
V
HGH
10.5
11.6
12.8
V
Pull Up Switch Resistance
R
DS(ON)
-1A transient
6
9
12
Pull Down Switch Resistance
R
DS(ON)
2.5A transient
2
3
4
Low side switching, rise time
tr
GL
10% to 90%
25
ns
Low side switching, fall time
tf
GL
10
ns
High side switching, rise time
tr
GH
40
ns
High side switching, fall time
tf
GH
10
ns
Dead time maximum
t
DEAD
I
DEAD
= 9
A
5500
ns
Dead time minimum
t
DEAD
I
DEAD
= 780
A
100
ns
NOTES:
1. Typical Data is for design information only.
2. Negative current is defined as coming out of (sourcing) the specified device pin.
Page 4
3932
THREE-PHASE POWER MOSFET CONTROLLER
ELECTRICAL CHARACTERISTICS at TA = +25C, V
BB
= 50 V, C
BOOT
= .1f, C
LOAD
=1000pf
(unless noted otherwise)
Characteristics
Symbol
Test Conditions
Min.
Typ.
Max.
Units
Bootstrap Capacitor
Bootstrap Capacitor Voltage
V
CAP
10.4
11.6
12.8
V
Bootstrap Charge Threshold
I
BOOTCHG
9
13
18
mA
Bootstrap Capacitor R
OUT
R
CAP
5
8
Charge Current
I
CX
100
mA
CAP Leakage Current
I
CAP
High Side switched ON
15
25
A
Current Limit Circuitry
Offset Voltage
V
IO
-5
0
5
mV
Input Bias Current
I
B
-5
0
A
Comparator Common Mode Range
V
CMR
0
1.5
V
RC Charge Current
I
RC
.9
1
1.1
A
V
RCL
1.0
1.1
1.2
V
RC Voltage Threshold
V
RCH
2.7
3.0
3.3
V
Protection Circuitry
Gate Source Monitor
UVLO
GS
V
CAP
-V
GHX
, High Side Switched ON
2.7
3.3
3.9
V
Short to Ground, Drain-Source
Monitor
UVLO
DS
V
BB
- V
SX
, High Side ON
1.6
2.0
2.4
V
Undervoltage Threshold
UVLO
V
REG
low to High
9.4
9.9
10.4
V
UVLO
V
REG
High to Low
8.8
9.3
9.8
V
Fault Output
V
FAULT
I
OL
= 1mA
.5
V
Tach Output
V
TACH
I
OL
= 500 A
.5
V
Thermal Shutdown Temp.
T
J
165
C
Thermal Shutdown Hysteresis
T
J
10
C
NOTES:
1. Typical Data is for design information only.
2. Negative current is defined as coming out of (sourcing) the specified device pin.
Page 5
3932
THREE-PHASE POWER MOSFET CONTROLLER
Pin Descriptions
RESET.
A logic input that enables the device, internally
pulled up to LCAP. Logic HIGH will disable the device and
turn off MOSFETs, coasting the motor. Logic LOW will
enable gate drive to follow commutation logic. This input
will override BRAKE.
GLC/GLB/GLA.
Low side gate drive outputs for external
MOSFET drivers. External series gate resistors can be used
to control slew rate seen at the power driver gate, thereby
controlling the di/dt and dv/dt of S outputs. The outputs will
source 1.25A for turn-on and sink 2.5A for gate discharge.
SC/SB/SA.
Directly connected to the motor terminals,
these pins sense the voltages switched across the load. The
pin is also connected to the negative side of the bootstrap
capacitor and negative supply connection for the floating
high side drive.
GHC/GHB/GHA.
High side gate drive outputs for n-
channel MOSFET drivers. External series gate resistors can
be used to control slew rate seen at the power driver gate,
thereby controlling the di/dt and dv/dt of S outputs. The
outputs will source 1.25A for turn-on and sink 2.5A for gate
discharge.
CC/CB/CA.
High side connection for bootstrap capacitor,
positive supply for high side gate drive. The bootstrap
capacitor is charged to approximately VREG when the
output Sx terminal is low. When the output swings high, the
voltage on this pin rises with the output to provide the
boosted gate voltage needed for N-channel power
MOSFETs.
MODE.
Logic input to set current decay method. Slow
decay mode (logic HIGH) switches off the high side FET in
response to PWM Off command. Fast decay mode (logic
LOW) switches off the source and sink MOSFET's. Mode
pin is internally pulled up to LCAP.
H1/H2/H3.
Hall sensor inputs, internally pulled up to
LCAP. Configured for 120-degree electrical spacing.
DIR.
Logic input to reverse rotation, see commutation logic
table. Internally pulled up to LCAP.
FAULT.
Open drain output to indicate fault condition. Will
go active high for any of the following fault conditions:
1)
Invalid HALL input code.
2)
High side gate-source undervoltage.
3)
Bootstrap capacitor not sufficiently charged.
4)
Undervoltage condition detected at VREG.
5)
Thermal Shutdown.
6)
Motor lead (SA/SB/SC) connected to ground.
Any fault will force a COAST condition, which turns all
power MOSFETs off. The fault state for gate-source and
bootstrap monitors is cleared at each commutation. If the
motor has stalled, the fault must be cleared by toggling the
RESET pin or repeating a power up sequence.
BRAKE.
Logic input for braking function. Logic LOW will
turn on sink side MOSFETs, turn off the source side
MOSFETs. This will effectively short the BEMF in the
windings and brake the motor. Internally pulled up to logic
LCAP.
SR.
Synchronous rectification input. Logic LOW disables
the feature forcing current decay through flyback diodes.
Logic HIGH will result in the opposite pair of drivers to
switch in response to a PWM "off" command. Internally
pulled up to LCAP.
TACH
. Digital output to indicate speed of rotation. A 3s
pulse appears at every Hall transition.
PWM
. Speed control input. Logic HIGH will turn on
MOSFETs selected by Hall input logic. Logic LOW turns
off the selected MOSFETs. The PWM input held high to
utilize internal current control circuitry. Internally pulled up
to logic LCAP.
RC.
Analog input. Connection for R
T
and C
T
to set the fixed
off time. The C
T
will also set the BLANK time. (see
applications information). It is recommended that the fixed
off time should not be less than 10
s. The resistor should be
in the range 10k to 500k.
SENSE.
Analog input to the current limit comparator.
Voltage representing load current appears on this pin.
Voltage transients seen at this pin when the drivers turn on
are ignored for time T
blank
.
PDF 
ZIP