A4937 Datasheet, PDF (1/3 Pages) Allegro MicroSystems – Automotive 3-Phase MOSFET Driver

A4937
Automotive 3-Phase MOSFET Driver
Features and Benefits
• High current 3-phase gate drive for N-channel MOSFETs
• SPI compatible serial control
• Cross-conduction protection
• Programmable dead time
• 5.5 to 50 V supply voltage range
• TTL inputs compatible with 3.3 V and 5 V logic
• Extensive diagnostics output
• Low current sleep mode
Applications
• Electronic power steering (EPS, EHPS, EAS)
• Hydraulic pumps
• Gearbox actuator
Package: 28-pin TSSOP with Exposed
Thermal Pad (suffix LP)
Not to scale
Description
The A4937 is a 3-phase controller for use with N-channel
external power MOSFETs and is specifically designed for
automotive applications.
A unique charge pump regulator provides full (>10 V) gate
drive for battery voltages down to 7 V and allows the A4937
to operate with a reduced gate drive, down to 5.5 V.
A bootstrap capacitor is used to provide the above battery
supply voltage required for N-channel MOSFETs.
Full control over all six power MOSFETs in the 3-phase bridge
is provided, through an SPI compatible serial interface, allowing
motors to be driven with block or overlap commutation. Power
output can be regulated by one or both of the PWM inputs.
The power MOSFETs are protected from shoot-through by
integrated crossover control and programmable dead time.
Integrated diagnostics provide indication of undervoltage,
overtemperature, and power bridge faults, and can be configured
to protect the power MOSFETs under most short circuit
conditions. Detailed diagnostics are available as a serial data
word.
The A4937 is supplied in a 28-pin TSSOP power package with
with exposed pad for enhanced thermal dissipation (package
type LP). This package is lead (Pb) free, with 100% matte-tin
leadframe plating.
Functional Block Diagram
V_BAT
A8450
Regulator
V_BAT
SPI
A4937
Micro-
controller
PWM
Reset
Diagnostics
3-Phase
BLDC
Motor
A4937A-DS