3946
Half-Bridge Power MOSFET Controller
A3946KLB SOIC
VREG
CP2
CP1
PGND
GL
S
Data Sheet
29319.150b
1
2
3
4
5
6
7
8
16 VBB
15 VREF
14 DT
13 LGND
12 RESET
11
IN2
The A3946 is designed specifically for applications 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
MOSFET
s. 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 rectifier.
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 packages: a
16-lead
SOIC
with internally fused leads (part number suffix
LB),
and
a 16-lead
TSSOP
with exposed thermal pad (suffix
LP).
Both packages
have a lead (Pb) free version, with 100% matte tin plated leadframes
(suffix
-T).
Scale 1:1
GH
BOOT
10 IN1
9
~FAULT
A3946KLP TSSOP with Exposed Thermal Pad
VREG
CP2
CP1
PGND
GL
S
GH
1
2
3
4
5
6
7
8
16 VBB
15 VREF
14 DT
13 LGND
12 RESET
11 IN2
10 IN1
9 ~FAULT
FEATURES
On-chip charge pump for 7 V minimum input supply voltage
High-current gate drive for driving a wide range of
N-channel
MOSFET
s
Bootstrapped gate drive with charge pump for 100% duty cycle
Overtemperature protection
Undervoltage protection
–40ºC to 135ºC ambient operation
Scale 1:1
BOOT
ABSOLUTE MAXIMUM RATINGS
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
2
Selection Guide
Part Number
A3946KLB
A3946KLB-T
A3946KLBTR
A3946KLBTR-T
A3946KLP
A3946KLP-T
A3946KLPTR
A3946KLPTR-T
Pb-free
–
Yes
–
Yes
–
Yes
–
Yes
Packing
47 pieces/tube
16-pin SOIC with internally
fused leads
1000 pieces/reel
96 pieces/tube
16-pin TSSOP with exposed
thermal pad
4000 pieces/reel
Package
Notes:
1. Measured on a two-sided PCB with 3 in.
2
of
2 oz. copper.
2. Measured on JEDEC standard High-K board.
A3946KLP .....................................
34°C/W
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
ALLEGRO [ ALLEGRO MICROSYSTEMS ]
