Automotive full-bridge gate driver IC has built-in fault detection

August 26, 2015 // By Graham Prophet
Designed for applications such as vehicles with integrated starter/generators (ISG), Allegro’s A5929 device has an independent “enable” function; it is a full-bridge gate driver IC designed to drive N-channel external power MOSFETs.

The device incorporates a charge pump regulator that provides a full gate drive voltage of greater than 10V at battery voltages down to 7V and allows operation with reduced gate drive at battery voltages down to 5.5V. A bootstrap capacitor is used to provide the battery supply voltage required for N-channel MOSFETs.

One logic level input is provided for each of the four power MOSFETs in the full-bridge, allowing motors to be driven with any PWM 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-circuit faults, supply undervoltage, and chip overtemperature conditions are indicated by a single open-drain fault output.

The A5929KLPTR-T is supplied in a 24-pin TSSOP power package with an exposed thermal pad (package type LP) for enhanced power dissipation. The device’s data sheet is  here.

Allegro MicroSystems;