BRAKE
4
5
6
7
8
9
2
3
PGND
DEAD
AGND
32
1
10
REF
GHC
26
27
28
29
19
24
25
SENSE
22
23
21
14
15
16
VBB
CA
FAULT
MODE
LCAP
VCCOUT
17
18
H1
19
20
Dwg. PP-068
11
12
13
30
31
GLC
SC
RESET
CC
GLB
SB
GHB
CB
GLA
SA
GHA
RC
PWM
BRKSEL
BRKCAP
BRAKE
DIR
H2
H3
CONTROL LOGIC
FAULT
Data Sheet
26301.100
The A3933SEQ is a three-phase MOSFET controller for use with
bipolar brushless dc motors. It drives all n-channel external power
FETs, allowing system cost savings and minimizing
r
(DS)on
power loss.
The high-side drive block is implemented with bootstrap capacitors at
each output to provide the floating positive supply for the gate drive.
The high-side circuitry also employs a unique "intelligent" FET
monitoring circuit that ensures the gate voltages are at the proper levels
before turn-on and during the ON cycle. This device is targeted for
applications with motor supplies from 12 V to 28 V.
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.
A power-loss braking circuit brakes the motor on an under-voltage
condition. The device is configured to either coast or dynamically
brake the motor when this occurs.
The A3933SEQ is supplied in a 32-lead rectangular (9 x 7) plastic
chip carrier (quad pack) for minimum-area, surface-mount applica-
tions.
3933
FEATURES
AND
BENEFITS
I Drives External N-Channel FETs
I Intelligent High-Side Gate Drive
I Selectable Coast or Dynamic Brake on Power Down
I Adjustable Dead Time for Cross-Conduction Protection
I Selectable Fast or Slow Current-Decay Modes
I Internal PWM Peak Current Control
I Reset/Coast Input
I 120 Hall Commutation with Internal Pullup
I Internal 5-V Regulator
I Low-Side Synchronous Rectification
I Direction Control
I PWM Speed-Control Input
I Fault-Diagnostic Output
I Under-Voltage Protection
THREE-PHASE POWER
MOSFET CONTROLLER
ABSOLUTE MAXIMUM RATINGS
at T
A
= 25
C
Supply Voltage, V
BB
............................. 28 V
(peak) .............................................. 30 V
Terminal Voltage, V
CCOUT
................. 13.2 V
(peak) .............................................. 15 V
Logic Input Voltage Range,
V
IN
.................. -0.3 V to V
LCAP
+ 0.3 V
Sense Voltage Range,
V
SENSE
............................. -5 V to V
LCAP
Output Voltage Range,
V
SA
, V
SB
, V
SC
.................. -5 V to +30 V
V
GHA
, V
GHB
, V
GHC
. -5 V to V
BB
+ 14 V
V
CA
, V
CB
, V
CC
..................... V
SX
+ 14 V
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
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
3933
THREE-PHASE POWER
MOSFET CONTROLLER
Copyright 1999, Allegro MicroSystems, Inc.
Functional Block Diagram
RECOMMENDED OPERATING CONDITIONS
Supply Voltage, V
BB
...................................... 15 V to 28 V
or, if V
BB
= V
CCOUT
................................... 12 V
10%
Logic Input Voltage Range, V
IN
.............. -0.3 V to +4.8 V
Sense Voltage Range, V
SENSE
........................ -1 V to +1 V
RC Resistance .......................................... 10 k
to 100 k
PWM Frequency, f
PWM
....................... 20 kHz to 100 kHz
Dwg. OA-007-32
LOW-SIDE
SYNCHRONOUS
RECTIFICATION
UNDER-
VOLTAGE
DETECT
BOOTSTRAP
CHARGE
TURN-ON
DELAY
TURN-ON
DELAY
DEAD-TIME
ADJUST
BOOTSTRAP
MONITOR
GATE-SOURCE
MONITOR
H1
H2
H3
DIR
RESET
MODE
PWM
REF
SENSE
BRAKE
BRKSEL
Dwg. FP-045
BRAKE
CONTROL
LOGIC
RC BLANKING
(FIXED OFF TIME)
REGULATOR
HIGH-SIDE
DRIVER
+
LCAP
V
CCOUT
LOW-SIDE
DRIVER
BOOTSTRAP LOW
V
GS
LOW
INVALID HALL
UNDERVOLTAGE
V
BB
1 OF 3 HIGH-SIDE DRIVERS
1 OF 3 LOW-SIDE DRIVERS
DEAD
FAULT
AGND
TO
1 OF 3
MOTOR
PHASES
TO
SENSE
+V
R
S
C
X
GH
X
S
X
GL
X
PGND
CONNECT FOR
12-V OPERATION
TO
LCAP
C
boot
BRKCAP
RC
TO
V
CCOUT
R
T
C
T
3933
THREE-PHASE POWER
MOSFET CONTROLLER
www.allegromicro.com
ELECTRICAL SPECIFICATIONS at T
A
= 25
C, V
BB
= V
CCOUT
= 12 V, C
load
= 1000 pF, C
boot
= 0.047
F
(unless noted otherwise).
Limits
Parameter
Symbol
Conditions
Min
Typ
Max
Units
Supply Current
Quiescent Current
I
BB
RESET low, f
PWM
= 40 kHz
16
19
mA
RESET high
15
17
mA
Reference Voltage
V
LCAP
4.75
5.0
5.25
V
Ref. Volt. Load Regulation
V
LCAP(
ILCAP)
I
LCAP
= 0 to -2 mA
10
25
mV
Output Voltage
V
CCOUT
V
BB
= 28 V
10.8
12
13.2
V
Output Voltage Regulation
V
CCOUT(
ICCOUT)
V
BB
= 28 V, I
CCOUT
= 0 to -10 mA
25
mV
Digital Logic Levels
Logic Input Voltage
V
IH
2.0
V
V
IL
0.8
V
Logic Input Current
I
IH
V
IH
= 2 V
<1.0
10
A
I
IL
V
IL
= 0.8 V
-70
-130
A
Gate Drive
Low-Side Output Voltage
V
GLxH
9.5
10.5
11.5
V
V
GLxL
I
GLx
= 1 mA
0.30
V
High-Side Output Voltage
V
GHxH
9.0
10.5
11.5
V
V
GHxL
I
GHx
= 1 mA
0.25
V
Low-Side Output
t
rGLx
1 V to 8 V
50
ns
Switching Time
t
fGLx
8 V to 1 V
40
ns
High-Side Output
t
rGHx
1 V to 8 V
100
ns
Switching Time
t
fGHx
8 V to 1 V
100
ns
DEAD Time
t
DEAD
I
DEAD
= 10
A
3000
ns
(Source OFF to Sink ON)
I
DEAD
= 215
A
180
ns
Continued --
NOTES: 1. Typical Data is for design information only.
2. Negative current is defined as coming out of (sourcing) the specified device terminal.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
3933
THREE-PHASE POWER
MOSFET CONTROLLER
ELECTRICAL SPECIFICATIONS at T
A
= 25
C, V
BB
= V
CCOUT
= 12 V, C
load
= 0.001
F, C
boot
= 0.047
F
(unless noted otherwise), continued.
Limits
Parameter
Symbol
Conditions
Min
Typ
Max
Units
Bootstrap Capacitor
Bootstrap Charge Current
I
Cx
50
100
150
mA
Bootstrap Output Voltage
V
Cx
Reference Sx
9.5
10.5
11.5
V
Leakage Current
I
Cx
High side switched high, Sx = V
BB
15
20
A
Current Limit
Offset Voltage
V
io
0
5.0
mV
Input bias current
I
SENSE
-1.0
A
RC Charge Current
I
RC
850
945
1040
A
RC Voltage Threshold
V
RCL
1.0
1.1
1.2
V
V
RCH
2.7
3.0
3.2
V
PWM frequency Range
f
PWM
Operating
20
100
kHz
Protection Circuitry
Undervoltage Threshold
UVLO
Increasing V
BB
9.7
10.2
10.7
V
Decreasing V
BB
9.35
10.35
V
Boot-Strap Capacitor Volt.
V
CxSx
V
BB
= 12 V
9.5
V
High-Side Gate-Source Volt.
V
GHxSx
6.3
V
Fault Output Voltage
V
FAULT
I
O
= 1 mA
0.8
V
Brake Function
Brake Cap. Supply Current
I
BRKCAP
V
BB
= 8 V, BRKSEL
2 V
30
A
Low-Side Gate Voltage
V
GLxH
V
BB
= 0, BRKCAP = 8 V
6.6
V
NOTES: 1. Typical Data is for design information only.
2. Negative current is defined as coming out of (sourcing) the specified device terminal.
3933
THREE-PHASE POWER
MOSFET CONTROLLER
www.allegromicro.com
Terminal
Name
1
PGND
2
RESET
3
GLC
4
SC
5
GHC
6
CC
7
GLB
8
SB
9
GHB
10
CB
11
GLA
12
SA
13
GHA
14
CA
15
V
CCOUT
16
LCAP
17
FAULT
18
MODE
19
V
BB
20
H1
21
H3
22
H2
23
DIR
24
BRAKE
25
BRKCAP
26
BRKSEL
27
PWM
28
RC
29
SENSE
30
REF
31
DEAD
32
AGND
RESET -- A logic input used to enable the device, internally
pulled up to V
LCAP
(+5 V). A logic HIGH will disable the
device and force all gate drivers to 0 V, coasting the motor. A
logic LOW allows the gate drive to follow commutation logic.
This input 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. Each output is designed and
specified to drive a 1000 pF load with a rise time of 50 ns.
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 capaci-
tors and are the negative supply connections for the floating
high-side drive.
GHA/GHB/GHC -- High-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. Each output is designed and
specified to drive a 1000 pF load with a rise time of 100 ns.
CA/CB/CC -- High-side connections for the bootstrap capaci-
tors, positive supply for high-side gate drive. The bootstrap
capacitor is charged to approximately V
CCOUT
when the
associated output SA/SB/SC 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
FETs.
Terminal Descriptions
continued next page
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