EZ2208 V1.0 Stepper driver

By adding a hysteresis function, SpreadCycle overcomes the issues that a constant TOFF chopper introduces to your mechanical system. It automatically applies a fitting relation between slow decay and fast decay to create the optimal fast decay for that cycle. The hysteresis function acts as a parachute that gently drops the current so it doesn't fall too quick, leading to an average current matching the target current. Besides resulting in a near-perfect current sine wave, the cycle-by-cycle chopper mode SpreadCycle also reduces current ripple and torque ripple.

Even at high RPM, where classic constant TOFF chopper modes show excessive deformations caused by the back-EMF of the motor, SpreadCycle remains highly effective. The motor control technology measures the current during each chopper cycle and automatically adjusts the hysteresis function to optimize the fast-decay phase. For more info on SpreadCycle and setting the parameters, please see our app note: Parameterization of SpreadCycle™.

A sensorless load measurement for stepper motors, StallGuard gives cost-effective feedback on the load-angle. The StallGuard sensitivity can be adjusted to fit the applications need, making it ideal for sensorless homing, self-calibration, distance measurement, or to verify all mechanics still function within the safety margins. Implemented in a standard stepper motor driver, the sensorless load detection eliminates the need for reference or limit switches and reduces cost and complexity of applications where precise referencing is required.

Normally, open-loop stepper drives lose step count in overload situations as they stall, for example when an axis is obstructed. StallGuard technology prevents step loss, keeping step count integrity by stopping the motor when the set load-value is reached. The sensorless technology can detect up to 1024 different load-levels, allowing for high-resolution feedback for continuous monitoring of the system.