Allegro MicroSystems offers the A5976, A5977, and A5979 microstep DMOS driver chips with converter and overcurrent protection

     Allegro MicroSystems' A5976, A5977 and A5979 are complete microstepper motor driver chips with built-in converters. They are designed to run bipolar stepper motors in full, half, quarter, eight-step (A5977), and 16-step (A5976/79) modes, with an output drive capacity of 40 V±2.8 A. The A5977 and A5979 include a fixed turn-off time current regulator capable of operating in slow, fast, or mixed attenuation modes.

     This current attenuation control scheme reduces the audible noise of the motor, improves the stepping accuracy and reduces the power consumption. The A5977 was designed to replace the A3977, a replacement for the A3979. The new equipment includes increased OCP(overcurrent protection) and lower R(DS(ON)) output for reduced power consumption and improved diagnostic nFAULT output (A5976). At present, there are no plans to discontinue the existing A3977 or A3979.

     This new series is targeted at the industrial, consumer and computer (IC&C) markets for applications such as office automation printers, scanners, copiers, textiles and sewing machines. This interface is ideal for applications where complex microprocessors are not available or are overburdened.