A4957 Datasheet, PDF (3/16 Pages) Allegro MicroSystems – The A4957 is a full-bridge controller for use with external N-channel power MOSFETs and is specifically designed for applications with high-power inductive loads such as brush DC motors.

A4957
Full Bridge MOSFET Driver
Functional Block Diagram
Battery +
VDD
FAULT
AHI
ALO
BHI
BLO
RESET
VBB
Diagnostics &
Protection
C_P
CP2 CP1
Charge
Pump
Regulator
VREG
C_REG
Bootstrap
Monitor
CA
C_BOOTA
High
Side
GHA
SA
R_GHA
Control
Logic
Low
Side
GND
GLA
R_GLA
Bootstrap
Monitor
CB
C_BOOTB
High
Side
GHB
SB
RDEAD
Low
Side
GLB
AGND GND
GND
Thermal Pad
VBAT
R_GHB
R_GLB
Allegro MicroSystems, Inc.
3
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com