DC Motor Pre-driver Saves Power, Reduces Damage
Mon, 04/07/2008 - 10:19am
Allegro MicroSystems, Inc. introduces its A4930 single-phase brushless DC motor pre-driver that provides outputs that can drive N-Channel MOSFET H-Bridges with voltage ranges from 8V to 36V. Targeting office automation, telecommunications, consumer and industrial applications, motor speed is regulated by either PWM or external analog voltage with programmable minimum speed and maximum motor current. Synchronous rectification is used in the PWM off-cycle to reduce power dissipation, and start-up current can be ramped up for reduced supply current surges and lock detection along with auto restart functions to reduce damage due to motor overheating. A single resistor programs the commutation delay. Protection features include thermal shutdown with hysteresis, UVLO and crossover current, and locked rotor protection with auto restart.