Toshiba Electronics Europe (TEE) has launched a new two-phase stepper motor driver. The TB6560A combines 1/16th step resolution with high output current capability, making it suitable for high accuracy, microcontroller-free micro-stepping control in office automation and industrial applications. In more complex systems, the TB6560A can be used to reduce the stepper control overhead on a host microcontroller, allowing a single microcontroller to control multiple motors.
Supplied in HZIP25 (TB6560AHQ) and HQFP64 (TB6560AFG) packaging, the new device is a single-chip, PWM chopper-type sinusoidal micro-step bipolar stepping motor driver delivering peak output currents of 3.5A. Incorporation of all PWM generation and encoding circuitry on-chip provides for the automatic generation of a smooth, sinusoidal micro-step waveform for the high performance driving of bipolar type stepper motors from a single clock signal. The sinusoidal output enables the construction of low-vibration drives, while built in overtemperature protection circuitry reduces the need for external components.
Providing both forward and reverse rotation control, Toshiba's new IC offers high flexibility by allowing phase drive selection for 2-phase, 1-2-phase, 2W1-2-phase and 4W1-2 phase excitation. The ability to configure torque settings and a Selectable Mixed Decay Mode (SMDM) provides good design flexibility. SMDM allows the ratio of various decay settings to be adjusted so that coil discharge pattern can be modified according to motor load and speed. Choosing a good mix of decay modes allows PWM ripple to be minimised, reducing both audible noise and vibration.
The new driver incorporates output monitor, reset and enable pins and features built-in 100kΩ pull-down resistors. Good thermal performance is achieved through a combination of low total bridge on resistance (0.6Ω) and packages designed for high allowable losses. Manufactured using a proprietary BiCD process, the TB6560A has a high output withstand voltage rating of 40V.
