Motors and Control

Three-Phase MOSFET Driver IC with On-Board Regulator

Allegro MicroSystems has announced a new three-phase MOSFET driver IC with an integrated low dropout regulator supplying 5V or 3.3V.  Allegro’s A4919 is designed for a wide range of industrial applications.  It can be controlled with block (trapezoidal), sinusoidal, or vector commutation when interfaced with a microprocessor.

The A4919 is designed to be a simple direct control gate driver for both the commercial and industrial markets providing LDO for peripherals or a microprocessor and provide complete flexibility over commutation.

A unique charge pump regulator provides full (>10 V) gate drive at power supply voltages down to 7V and allows the A4919 to operate with reduced gate drive at power supply voltages down to 5.5V. A bootstrap capacitor is used to provide the above power supply voltage required for the high side N-channel MOSFETs.

One logic-level input is provided for each of the six power MOSFETs in the three-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 under voltage, and chip overtemperature conditions are indicated by a single open-drain fault output.  Product variants include either 5.0V or 3.3V LDO or an option without LDO and instead provides a voltage input which can be used to monitor an external voltage source.

Summary of features and benefits:

  • High current 3-phase gate drive for n-channel MOSFETs
  • Individual inputs/control for each MOSFET
  • 5V to 50V Supply Voltage Range
  • Optional Regulated Logic Supply Voltage Output (3V and 5V)
  • Motor phase short to supply and short to ground detection
  • Under voltage, over temperature monitor
  • Cross-conduction protection
  • Low Current Sleep Mode

The A4919 is supplied in a 28-pin TSSOP power package (package type LP) and a 28-terminal 5 mm × 5 mm × 0.90 mm (QFN package) both with an exposed pad for enhanced thermal performance. Both packages are lead (Pb) free, with 100% matt-tin leadframe plating (suffix T).

Allegro MicroSystems, Inc. , Allegro MicroSystems Europe
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