Allegro unveils three-phase gate driver for EV and hybrid cars
From Allegro MicroSystems comes the QuietMotion product line with the introduction of the A89307 automotive-qualified gate driver integrated circuit.
Designed for battery cooling fans and HVAC systems in electric and hybrid vehicles, the A89307 offers low noise and vibration by using a field orientated control algorithm to drive continuous sinusoidal current to the load. This helps car manufacturers reduce noise and improve battery life, offering more miles per charge and lowering vehicle carbon footprints, says Allegro.
“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 A89307 includes a hardware-based algorithm, which requires no external sensors or software development; the user selects parameters using a GUI interface and loads them into the IC’s on-chip EEPROM. With only five external components, the A89307 helps designers lower material costs by reducing BOM components and facilitating very small system footprints for in-motor PCBs. Its fully integrated algorithm can even eliminate the need for a separate microprocessor.
Modes of operation include open-loop PWM or fully programmable closed-loop speed control. In closed-loop mode, the customer can program the PWM-to-speed relationship to match the PWM commands provided by an external ECU. Field weakening is included to improve performance at high speed. Low-speed operation and windmilling start-up are just a few of the features included in the A89307 hardware based digital algorithm.
While designed for xEV battery cooling fans, the A89307 can also be used in HVAC blowers as well as liquid pumps in traction inverter cooling systems. The external gate drive allows the device to be flexible enough to drive a wide range of motor powers up to 500W.