Allegro Introduces Single Phase Fan Pre-Driver

Allegro A4930

Designed for pulse width modulated (PWM) current control of single phase brushless fans, the A4930 minimizes external component count and integrates all the key features required for high-current fans. Internal synchronous rectification control circuitry is provided to improve power dissipation in the external MOSFETs during PWM operation. Internal circuit protection includes thermal shutdown with hysteresis, rotor lock, and dead time protection.

The A4930 is supplied in a 0.90 nominal overall height, 5 mm × 5 mm, 28-pin QFN with exposed thermal pad, (suffix ET). It is lead (Pb) free with 100% matte tin leadframe plating.

Features and Benefits

  • Synchronous rectification for low power dissipation
  • Drives four N-channel MOSFETs
  • Internal UVLO and thermal shutdown circuitry
  • Hall element input
  • PWM current limiting
  • Dead time protection
  • FG output
  • RD output
  • Lock detect protection
  • High VBB absolute maximum
  • Soft start