Stable and precise control make stepper motors sutiable for applications such as printers, office appliances and industrial equipment.

To avoid stalling and achieve stable operation sufficient current margin is needed.  To improve efficiency and suppress excess heat generation torque margin control is highly desirable. This could require complicated current adjustment by real-time monitoring of motor torque and current feedback, using additional sensors and microcontrollers. To solve these problems, Toshiba has developed Active Gain Control (AGC) technolgoy.  AGC automatically optimizes the motor current depending on the torque needed. It prevents motors from stalling and provides the optimum efficient motor control solution.

To provide sufficient margin for the motor torque required, motor control drivers (MCDs) generally supply a motor drive current greater than the peak current at the maximum load. This means that extra current continues flowing all the time. In order to minimize unnecessary current consumption, a sensor or a microcontroller is used to monitor the changes in load conditions, thereby adjusting the motor drive current according to the load conditions. This feedback process requires extremely complicated control. Toshiba offers motor driver ICs incorporating Active Gain Control (AGC) technology, which sense a motor's load torque and automatically optimizes the motor drive current. This makes it possible to prevent a motor from going out of step while simplifying high-efficiency motor control.

Active Gain Control (AGC) technology automatically adjusts a motor drive current according to a motor's load conditions in order to reduce extra current, thereby considerably reducing the amount of heat generated by the motor driver IC and the motor. This helps reduce overall heat generation in a system and the resulting degradation.

Toshiba offers various stepping motor drivers that deliver the substantial benefits of Active Gain Control (AGC). Stepping motor drivers with a clock input and those with a phase input are both available. If you want to evaluate your product plan or design using a stepping motor incorporating AGC technology, reference designs are available for download.