The sensorless design of the TC78B009FTG does not require Hall effect sensors, making it suitable for applications involving high-velocity fans or impellers in servers, blowers, small pumps, cordless vacuums and robotic cleaners.
High-speed rotation is made possible due to a 150° rectangular wave drive. The rotational position of the motor is detected by the induced voltage, eliminating the need for three Hall effect sensors which reduces the size of the controller as well as eliminating cost from the design.
The new TC78B009FTG can control eight levels of gate drive current for MOSFETs, thereby providing slew rate control. In addition, a closed loop speed control regulates and maintains the motor rotational speed during dynamic power fluctuations and load variations.
Precise setting of a speed profile is performed by the built-in non-volatile memory (NVM), which Toshiba explains allowis the TC78B009FTG to eliminate the need for an analogue front end. The company also says there is no need for an external MCU with a feedback algorithm for closed loop speed control.
The new controller also features a current monitoring function with analogue output, allowing the host to detect the motor drive level and make real-time adjustments in the application.
The TC78B009FTG can operate with either closed loop or open loop speed control, with speed controlled by either a PWM signal, analogue voltage or via the I2C interface. The I2C interface can also be used to set and configure various operational parameters. The new controller is housed in a WQFN36 package measuring 5 mm x 5 mm x 0.8 mm.
Toshiba said that mass production shipments of the new TC78B009FTG brushless motor controller started earlier this month.
