Always order by complete part number, e.g., A3940KLP .
Data Sheet
29319.100
g
FULL-BRIDGE POWER MOSFET CONTROLLER
-- For Automotive Applications
3940
The A3940KLP and A3940KLW are designed specifically for
automotive applications that require high-power motors. Each provides
four high-current gate drive outputs capable of driving a wide range of
n-channel power MOSFETs in a full-bridge configuration.
Bootstrap capacitors are utilized to provide the above-battery
supply voltage required for n-channel FETs. An internal charge pump
for the high side allows for dc (100% duty cycle) operation of the
bridge.
Protection features include supply under/overvoltage, thermal
shutdown, and motor lead short-to-battery and short-to-ground fault
notification, and a programmable dead-time adjustment for cross-
conduction prevention.
The
overvoltage trip point is user adjustable.
The A3940 is supplied in a choice of two power packages, a 28-
lead TSSOP with an exposed thermal pad (suffix LP), and a 28-lead
wide-body SOIC (suffix LW).
FEATURES
!
!
!
!
!
Drives wide range of n-channel MOSFETs
!
!
!
!
!
Charge pump to boost gate drive at low-battery-input conditions
!
!
!
!
!
Bootstrapped gate drive with charge pump for 100% duty cycle
!
!
!
!
!
Synchronous rectification
!
!
!
!
!
Fault diagnostic output
!
!
!
!
!
Adjustable dead-time cross-conduction protection
!
Motor lead short-to-battery and short-to-ground protection
!
Undervoltage/overvoltage protection
!
!
!
!
!
-40C to +150C, T
J
operation
!
!
!
!
!
Thermal shutdown
ABSOLUTE MAXIMUM RATINGS
Load Supply Voltage Range, VBB,
VDRAIN, CP1 .......... -0.6 V to +40 V
Output Voltage Ranges,
LSS .............................. -2 V to +6.5 V
GHA/GHB, V
GHX
........ -2 V to +55 V
SA/SB, V
SX
.................. -2 V to +45 V
GLA/GLB, V
GLX
.......... -2 V to +16 V
CA/CB, V
CX
.............. -0.6 V to +55 V
CP2,VCP, VIN .......... -0.6 V to +52 V
Logic Input/Output Voltage Range
V
IN
, V
OUT
................... -0.3 V to +6.5 V
Operating Temperature Range,
T
A
........................... -40C to +135C
Junction Temperature, T
J
......... +150C*
Storage Temperature Range,
T
S
........................... -55C to +150C
* Fault conditions that produce excessive
junction temperature will activate device
thermal shutdown circuitry. These conditions
can be tolerated, but should be avoided.
A3940KLP
(TSSOP with exposed
thermal pad)
A3940KLW
(SOIC)
Approx. 2X actual size.
4
3
2
1
8
5
12
11
10
9
21
22
23
24
17
20
15
16
27
28
14
13
19
18
25
26
6
7
4
3
2
1
8
5
12
11
10
9
21
22
23
24
17
20
15
16
27
28
14
13
19
18
25
26
6
7
3940
FULL-BRIDGE POWER
MOSFET CONTROLLER
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
2
Functional Block Diagram
Copyright 2003 Allegro MicroSystems, Inc.
See pages 7 and 8 for terminal assignments and descriptions.
3940
FULL-BRIDGE POWER
MOSFET CONTROLLER
www.allegromicro.com
3
* Measured on "High-K" multi-layer PWB per JEDEC Standard JESD51-7.
Measured on typical two-sided PWB .
A3940KLW (SOIC)
A3940KLP (TSSOP)
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 responsi-
bility for its use; nor for any infringement of patents or other rights of
third parties which may result from its use.
3940
FULL-BRIDGE POWER
MOSFET CONTROLLER
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
4
ELECTRICAL CHARACTERISTICS:
unless otherwise noted at T
A
= -40C to +135C, T
J
= -40C to +150C,
V
IN
V
BB
= 7 V to 40 V, C
p
= 0.47 F, C
r
= 1 F, C
REG5
= 0.1 F, C
REG13
= 10 F, C
BOOT
= 0.1 F, PWM = 22.5 kHz
square wave.
Limits
Characteristics
Symbol
Conditions
Min
Typ
Max
Units
Power Supply
V
BB
Quiescent Current
I
BB
RESET = 1, V
BB
= V
IN
= 40 V, V
IN
V
CP
,
4.8
7.0
mA
coast, stopped, CP disabled, I
DEAD
= 170 A
RESET = 1, V
BB
= V
IN
= 15 V, V
IN
V
CP
,
4.3
7.0
mA
coast, stopped, CP disabled, I
DEAD
= 170 A
RESET = 1, V
BB
= V
IN
= 40 V, V
IN
V
CP
, coast,
5.0
7.0
mA
stopped, I
DEAD
= 170 A, I
CP
= 0 mA
RESET = 1, V
BB
= V
IN
= 15 V, V
IN
V
CP
, coast,
4.8
7.0
mA
stopped, I
DEAD
= 170 A, I
CP
= 0 mA
RESET = 1, V
BB
= V
IN
= 40 V, V
IN
V
CP
, coast,
35.4
40.0
mA
stopped, I
DEAD
= 170 A, I
CP
= 15 mA
RESET = 1, V
BB
= V
IN
= 15 V, V
IN
V
CP
, coast,
35.1
40.0
mA
stopped, I
DEAD
= 170 A, I
CP
= 15 mA
RESET = 0
1.0
A
VREG5 Output Voltage
V
REG5
No load
4.5
5.0
5.5
V
VREG5 Line Regulation
V
REG5
I
REG5
= 4.0 mA
5.0
mV
VREG5 Load Regulation
V
REG5
I
REG5
= 0 - 4.0 mA, V
BB
= 40 V
5.0
mV
VREG5 Short-Circuit Current
I
REG5M
V
BB
= 40 V, V
REG5
= 0
28
mA
VCP Output Voltage Level
V
CP
V
BB
= 14 - 40 V, I
CP
= 15 mA
V
BB
+9.5 V
BB
+10.7 V
BB
+11.8
V
V
BB
= 7 V, I
CP
= 15 mA
11.7
13
13.8
V
VCP Gate Drive
I
CP
SR = 1, MODE = 0, ENABLE = PWM
15
mA
VCP Output Voltage Ripple
V
CP(PP)
I
CP
= 15 mA, V
BB
= 14 V - 40 V
500
mV
VCP Pump-Up time
t
up
V
IN
= V
CP
, V
BB
= 14 V - 40 V
2.5
ms
V
IN
= V
CP
, V
BB
= 7 V
3.5
ms
VREG13 Quiescent Input Current
I
REG13
RESET = 1, V
BB
= V
IN
= 40 V, coast, stopped
1.4
mA
VREG13 Output Voltage
V
REG13
V
IN
= 15 V, no load
12.6
13.3
14.0
V
VREG13 Dropout Voltage
V
REGDV
I
REG13
= 15 mA, V
IN
= 11 V - 14 V
0.7
V
VREG13 Line Regulation
V
REG13
V
IN
= 15 V - 40 V, I
REG13
= 15 mA
2.0
mV
VREG13 Load Regulation
V
REG13
V
IN
= 40 V, I
REG13
= 0 - 15 mA
2.0
mV
VREG13 Short-Circuit Current
I
REG13M
V
IN
= 40 V, V
REG13
= 0 (pulse)
60
mA
Go-to-Sleep Response Time
t
sleep
RESET = 0 to V
REG5
= 4 V
10
30
s
Wake-Up Response Time
t
wake
RESET = 1 to V
REG13
, UV cleared
1.4
ms
NOTES: Typical Data is for design information only.
Negative current is defined as coming out of (sourcing) the specified device terminal.
Continued next page ...
3940
FULL-BRIDGE POWER
MOSFET CONTROLLER
www.allegromicro.com
5
Continued next page ...
ELECTRICAL CHARACTERISTICS:
unless otherwise noted at T
A
= -40C to +135C, T
J
= -40C to +150C,
V
IN
V
BB
= 7 V to 40 V, C
p
= 0.47 F, C
r
= 1 F, C
REG5
= 0.1 F, C
REG13
= 10 F, C
BOOT
= 0.1 F, PWM = 22.5 kHz
square wave.
Limits
Characteristics
Symbol
Conditions
Min
Typ
Max
Units
Control Logic
Logic Input Voltage
V
IN(1)
HIGH level input (Logic 1), except RESET.
2.0
V
V
IN(1)
HIGH level input (Logic 1) for RESET
2.2
V
V
IN(0)
LOW level input (Logic 0)
0.8
V
Logic Input Current
I
IN(1)
V
IN
= 2.0 V
40
100
A
I
IN(0)
V
IN
= 0.8 V, except RESET(0)
16
40
A
I
IN(0)
V
IN
= 0.8 V, RESET(0)
1.0
A
Gate Drives, GHx, GLx ( internal SOURCE or upper switch stages)
Output High Voltage
V
DSL(H)
GHx: I
xU
= -10 mA, V
sx
= 0
V
REG13
- 2.2
V
REG13
V
GLx: I
xU
= -10 mA, V
lss
= 0
V
REG13
- 0.2
V
REG13
V
Source Current (pulsed)
I
xU
V
SDU
= 10 V, T
J
= 25C
700
mA
V
SDU
= 10 V, T
J
= 135C
400
mA
Source ON Resistance
r
SDU(on)
I
xU
= -150 mA, T
J
= 25C
4.0
13
I
xU
= -150 mA, T
J
= 135C
7.0
23
Source Load Rise Time
t
r
Measure V
DSL
, 20% to 80%, C
L
= 3300 pF
90
ns
Gate Drives, GHx, GLx ( internal SINK or lower switch stages)
Output Low Voltage
V
DSL(L)
GHx: I
xL
= 10 mA, V
sx
= 0
150
mV
GLx: I
xL
= 10 mA, V
lss
= 0
150
mV
Sink Current (pulsed)
I
xL
V
DSL
= 10 V, T
J
= 25C
800
mA
V
DSL
= 10 V, T
J
= 135C
550
mA
Sink ON Resistance
r
DSL(on)
I
xL
= +150 mA, T
J
= 25C
1.8
6.0
I
xL
= +150 mA, T
J
= 135C
3.0
7.5
Sink Load Fall Time
t
f
Measure V
DSL
, 80% to 20%, C
L
= 3300 pF
70
ns
Gate Drives, GHx, GLx (General)
Propagation Delay
t
pd
Logic input to unloaded GHx, GLx
225
ns
Output Skew Time
t
sk(o)
Grouped by rising or falling edge
50
ns
Dead Time
t
dead
LONG = 0, R
DEAD
= 12.1 k
(I
DEAD
= 167 A)
0.3
s
(Shoot-Through Prevention)
LONG = 0, R
DEAD
= 499 k
(I
DEAD
= 4 A)
11.0
s
Between GHx, GLx transitions
LONG = 1, R
DEAD
= 12.1 k
(I
DEAD
= 167 A)
8.3
s
of same phase
LONG = 1, R
DEAD
= 499 k
(I
DEAD
= 4 A)
345
s
NOTES: Typical Data is for design information only.
Negative current is defined as coming out of (sourcing) the specified device terminal.
For GH
X
: V
SDU
= V
CX
V
GHX
, V
DSL
= V
GHX
V
SX
, V
DSL(H)
= V
CX
V
SDU
V
SX
.
For GL
X
: V
SDU
= V
REG
V
GLX
, V
DSL
= V
GLX
V
LSS
, V
DSL(H)
= V
REG
V
SDU
V
LSS.
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