The A5976, A5977 and A5979 of Allegro MicroSystems are complete micro stepping motor driver chips with built-in converters. They are designed to operate bipolar stepper motors in full, half, quarter, eight step (A5977), and sixteen step (A5976/79) modes with an output drive capacity of 40 V ± 2.8 A. The A5977 and A5979 include a fixed off time current regulator capable of operating in slow, fast or mixed decay modes.
This current attenuation control scheme reduces the audible noise of the motor, improves the step accuracy and reduces the power consumption. A5977 is designed to replace A3977, and A5979 is the replacement of A3979. The new equipment includes increased OCP (over-current protection) and lower R (DS (ON)) output to reduce power consumption and improve the nFAULT output of diagnosis (A5976). At present, there is no plan to stop the existing A3977 or A3979.
This new series is aimed at industrial, consumer and computer (IC&C) market applications such as office automation printers, scanners, copiers, textiles and sewing machines. This interface is ideal for applications where complex microprocessors are unavailable or overburdened.
Package LP, 28-Pin TSSOP
