Automotive Three Phase MOSFET Driver

The A4939 is a three-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 at battery voltages down to 7 V and allows the A4939 to operate with reduced gate drive at battery voltages down to 5.5 V. A bootstrap capacitor is used to provide the above battery supply voltage required for N-channel MOSFETs.

One logic level input is provided for each of the six power MOSFETs in the 3-phase bridge, allowing motors to be driven with any commutation scheme defined by an external controller. The power MOSFETs are protected from cross-conduction by integrated crossover control.

Motor phase short-to-supply and short-to-ground detection is provided by independent drain-source voltage monitors on each MOSFET. Short faults, supply undervoltage, and chip overtemperature conditions are indicated by a single open drain fault output.

Allegro recommended automotive qualified hall latches: APS122x5 and APS122x0

Product variants incorporating a low drop out (LDO) regulator to source either 5.0 V or 3.3 V to external circuitry are available. The A4939 is supplied in a 28-pin TSSOP power package with an exposed thermal pad (package type LP). This package is lead (Pb) free, with 100% matte tin leadframe plating (suffix T).

Applications

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