Data Sheet
29319.150
3946
Half-Bridge Power MOSFET Controller
The A3946 is designed specifi cally for ap pli ca tions that require
high power unidirectional dc motors, three-phase brushless dc motors, or
other inductive loads. The A3946 provides two high-current gate drive
outputs that are capable of driving a wide range of power N-channel
MOSFETs. The high-side gate driver switches an N-channel MOSFET
that controls current to the load, while the low-side gate driver switches
an N-channel MOSFET as a synchronous rectifi er.
A bootstrap capacitor provides the above-battery supply voltage
required for N-channel MOSFETs. An internal charge pump for the
high side allows for dc (100% duty cycle) operation of the half-bridge.
The A3946 is available in a choice of two power pack ag es: a
16-lead SOIC with copper batwing power tab (part number suffi x LB),
and a 16-lead TSSOP with ex posed thermal pad (suffi x LP).
„ On-chip charge pump for 7 V minimum input supply voltage
„ High-current gate drive for driving a wide range of
N-channel MOSFETs
„ Bootstrapped gate drive with charge pump for 100% duty cycle
„ Overtemperature protection
„ Undervoltage protection
„ –40ºC to 135ºC ambient operation
Always order by complete part number:
Load Supply Voltage, V
BB
............................. 60 V
Logic Inputs ..................................–0.3 V to 6.5 V
Pin S……..........................................–4 V to 60 V
Pin GH ...........................................–4 V to 75 V
Pin BOOT….. ................................–0.6 V to 75 V
Pin DT ........................................................ V
REF
Pin VREG ......................................–0.6 V to 15 V
Package Thermal Resistance, R
JA
A3946KLB..................................... 48°C/W
1
A3946KLB..................................... 38°C/W
2
A3946KLP ..................................... 44°C/W
1

A3946KLP ..................................... 34°C/W
2
Operating Temperature Range, T
A
.. –40°C to +135°C
Junction Temperature, T
J
...........................+150°C
Storage Temperature Range, T
S
....-55°C to +150°C
Notes:
1. Measured on a two-sided PCB with 3 in.
2
of
2 oz. copper.
2. Measured on JEDEC standard High-K board.
AB SO LUTE MAX I MUM RAT INGS
A3946KLB SOIC
A3946KLP TSSOP with Exposed Thermal Pad
3
4
5
6
7
8
2
1
14
13
12
11
10
9
15
16VREG
CP2
CP1
PGND
GL
S
GH
BOOT
VBB
VREF
DT
LGND
RESET
IN2
IN1
~FAULT
FEATURES
Scale 1:1
Scale 1:1
3
4
5
6
7
8
2
1
14
13
12
11
10
9
15
16VREG
CP2
CP1
PGND
GL
S
GH
BOOT
VBB
VREF
DT
LGND
RESET
IN2
IN1
~FAULT
Part Number Package
A3946KLB
A3946KLP
16-Lead SOIC; Copper Batwing Power Tab
16-Lead TSSOP; Exposed Thermal Pad