Sinusoidal Three-Phase Gate Controller Goes Sensorless

Designed for the automotive market, the A4964 three-phase, sensorless, brushless DC (BLDC) motor controller operates with external N-channel power MOSFETs. The device provides motor control functions in a system where a small microcontroller provides the communication interface to a central ECU and intelligent fault and status handling. The A4964 provides the supply and watchdog for the microcontroller and the high-voltage interfaces between the microcontroller and the central ECU and ignition switch. It can also operate as an independent single chip remote motor controller.

 

Motor drive is developed using a three-phase sinusoidal current drive where phase commutation is determined, without the need for independent position sensors, by monitoring the motor back-EMF. The sensorless start-up scheme includes forward and reverse pre-rotation (windmill) detection and synchronization, and allows the device to operate over a wide range of motor and load combinations.

Free Newsletter

Like this article? Subscribe to FierceSensors!

The sensors industry is constantly changing as innovation runs the market’s trends. FierceSensors subscribers rely on our suite of newsletters as their must-read source for the latest news, developments and analysis impacting their world. Register today to get sensors news and updates delivered right to your inbox.

 

Three control modes are on tap: open loop (voltage) control, current (torque limit) control, and closed-loop speed control. The control mode, operating mode, and bridge parameters are programmed through an SPI-compatible serial interface. A single current sense amplifier provides peak current limiting and average current measurement through the serial interface. Also, integrated diagnostics provide indication of under-voltage, over-temperature, and power bridge faults and can protect the power switches under most short-circuit conditions.

 

The A4964 comes in both a 36-terminal QFN and a 32-lead QFP, both with an exposed thermal pad. Prices are $6.16 each/1,000 for the A4964KEVTR-J and $6.59 each/1,000 for the A4964KJPTR-T. For more spec, an A4964 datasheet is available. For more info, contact

Allegro MicroSystems, Worcester, MA. 508-853-5000

Suggested Articles

OmniVision's new OX01F10 SoC module provides automotive designers with a small form factor with low-light performance, ultra-low power and reduced cost.

Several industry leaders have formed a QSFP-DD800 Multi-Source Agreement (MSA) Group to expedite development of high-speed, double-density, quad small form…

NXP Semiconductors N.V. has announced its secure fine ranging chipset, SR100T, to achieve precise positioning performance for next-generation UWB-enabled…