This new device includes a back-electromotive force filter to ensure more stable control of the sensor-less square wave during startup and low speed conditions and also includes a hardware MDU to provide increased calculation speed. These features make the device suitable for use in various square wave and sinusoidal wave BLDC motor applications.

The device contains 8K×16 of Flash Program Memory, 2048 bytes of RAM Data Memory, 512 bytes of EEPROM, an operating frequency of up to 20MHz, a (10+1)-channel high speed 12-bit analog to digital converter and four timers which can implement PWM output/capture input functions.

For BLDC control, the device provides a BLDC motor control circuit, which contains a 16-bit timer for rotational speed monitoring, three 10-bit complementary PWM outputs with a dead-time function as well as an over current protection (OCP) function.

The device integrates three comparators for Hall element or sensor-less position detection. The device also provides a hardware cycle-by-cycle current protection control function. These features allow users to setup the output current limit directly allowing the motor to maintain running within the maximum protection current parameters.

The BD66FM5250 is available in 24/28-pin SSOP and 32-pin QFN (4×4) package types. Holtek also provides a BD66FM Series BLDC Workshop to assist users to reduce their product development time.