Bipolar stepping motor driver minimises vibration and acoustic noise
Stepper motor drivers from Toshiba now include a compact device offering a maximum output withstand voltage of 40V and output current of 2.0A. The TC78S122FTG will save space, reduce power consumption, lower heat dissipation and minimise vibration and acoustic noise in high-speed motion control designs, says the company. Target applications include surveillance cameras, ATMs, office automation equipment, factory automation and home appliances.
The two-in-one chip delivers a two-channel drive function, capable of running two stepping motors simultaneously. The integration frees up board space to help reduce device size. The driver can simultaneously drive two channels thanks to a low maximum on resistance of 0.6Ohm (a reduction of 50 per cent compared to previous products) that cuts heat generation.
Instead of regulator circuit for the IC’s internal logic operating at standby, this driver can stop the regulator at standby due to a sleep function. Consequently, IC power consumption is reduced. As well as driving the stepping motors, it also provides an interface for driving brushed DC motors. For example, this could include one-channel for the stepping motor, and two channels for running brushed DC motors.
High-resolution motor driving of quarter steps (maximum) and a decay mode switching function for constant current control reduce vibration and noise, says the company. Built-in error detection features include a thermal shutdown circuit and an over-current shutdown circuit to provide enhanced reliability and safety.
It is housed in a compact QFN package that measures 7.0 x 7.0 x 0.9mm.