Gate driver keeps batteries and HVAC systems running quiet and cool

01-11-2021 | Allegro | Automotive & Transport

Allegro MicroSystems expands its QuietMotion product line with the introduction of the new A89307 automotive-qualified gate driver IC. Designed for battery cooling fans and HVAC systems in EV and HEV, the device provides ultra-low noise and vibration by using a FOC algorithm to drive continuous sinusoidal current to the load, assisting automakers to reduce noise and improve battery life, providing more miles per charge and reducing vehicle carbon footprints.

“By design, EV and hybrid vehicles are quieter than traditional models with internal combustion engines - especially when they’re stopped – and drivers are becoming increasingly sensitive to noise created by components such as cooling fans,” said Steve Lutz, product line director for Motor Drivers at Allegro. “The A89307’s hardware-based algorithm makes it easier for designers to reduce fan noise while improving cooling performance and increasing miles per charge. That’s good for drivers and good for the environment.”

The device includes a hardware-based algorithm, which needs no external sensors or software development; the user just selects parameters using a simple GUI and loads them into the IC’s on-chip EEPROM. With five external components, it assists designers to lower material costs by decreasing BOM components and helping very small system footprints for in-motor PCBs. Its fully integrated algorithm can even eradicate the necessity for a separate microprocessor.

Modes of operation include open-loop PWM or fully programmable closed-loop speed control. In closed-loop mode, users can program the PWM-to-speed relationship to match the PWM commands given by an external ECU. Field weakening is incorporated to better performance at high speed. Low-speed operation and windmilling start-up are only a few of the features included in the hardware-based digital algorithm.

While designed for xEV battery cooling fans, the device can also be employed in HVAC blowers and liquid pumps in traction inverter cooling systems. The external gate drive allows the device to be flexible enough to drive an extensive range of motor powers up to 500W. The device is available in a 28L wettable flank QFN package.

By Natasha Shek