Delivering high-efficiency, low-vibration, and low-noise motor operation
Toshiba Electronics Europe has launched the next-generation stepper motor driver IC, the TB67S579FTG, featuring Advanced Microstep Technology
This two-phase, bipolar stepper motor driver utilises constant-current control. With its advanced functions, it can achieve high efficiency, low vibration, and low noise in motor operation. Target applications include office equipment and a range of commercial and industrial equipment.
The high-efficiency stepper motor driver IC is Toshiba’s first product with the newly developed Advanced Microstep Technology, which includes second-generation Active Gain Control (AGC2), the Automatic Wave Generation System (AWGS), and the Continuous Microstepping.
Continuous Microstepping reduces vibration and noise, especially at low speeds, by creating a continuous, sinusoidal motor drive current waveform.
Typical microstep control methods require increasing the input clock (CLK) frequency in proportion to the number of microsteps. AWGS is a function that enables driving a stepper motor in microstepping using a CLK signal as needed for full-step rotation control. In applications where a stepper motor is driven in full-step mode to quickly generate torque, then switched to microstepping for lower vibration and noise, a smooth transition can be achieved without adjusting control signals. As a result, the processing load on control devices can be reduced.
AGC2 can detect the induced voltage during motor operation to determine the load and automatically adjust the required motor drive current. This enables the motor to operate with the minimum required current under light-load conditions, resulting in higher efficiency and lower power consumption. AGC2 can also enhance the current waveform and torque by realising a ‘full’ full-step operation.
In addition to the conventional GPIO configuration interface, the TB67S579FTG provides a flexible serial configuration interface, allowing easy adjustment of advanced features without increasing pin count or system complexity.
The TB67S579FTG’s output stage has an RDS of 0.6Ω. When in sleep mode, the device draws a maximum current of 1mA. To simplify system integration, the driver operates with a single motor power supply, ranging from 4.5V to 34V. The product also uses Toshiba’s Advanced Current Detection System (ACDS), eliminating the need for external current-sense resistors. The built-in charge pump circuit does not need an external capacitor. Eliminating the need for these external components saves space in the mounting area and reduces the bill of materials cost.
Additional features include Advanced Dynamic Mixed Decay (ADMD), which can achieve up to 30% higher rotation speed without increasing noise or vibration. The driver IC implements comprehensive protection functions, including overcurrent detection, thermal shutdown, under-voltage lockout, error flag output, and open-load and stall detection. The integrated stall detection function reliably identifies motor lock conditions, enhancing operational safety and preventing potential damage to mechanical components and electronics.
