A4937: Automotive 3-Phase MOSFET Driver


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.

Allegro recommended automotive qualified hall latches: APS122x5 and APS122x0

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.


  • Electronic power steering (EPS, EHPS, EAS)
  • Hydraulic pumps
  • Gearbox actuator

Top Features

  • 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

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Part Composition /
RoHS Data
Comments Samples Check Stock
A4937KLPTR-A-T 28-lead TSSOP -40°C to 125°C Yes View Data Contact your
local sales rep
Distributor Stock
APEK4937KLP-01-T DEMO BOARD -40°C to 125°C No -- Contact your
local sales rep
Distributor Stock

Allegro’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of Allegro’s product can reasonably be expected to cause bodily harm.

Design Support Tools

Allegro Customer Portal: Gain access to Allegro product software and design tools.

NOTE: When ordering, please also request APEK-USBCBLE-T.

A4937 Demo board Schematic/Layout