Compact 3 phase BLDC motor drive with texas instruments' C2000 series control card interface. Designed for 500W electric motors, using classic 2 level inverter topology with an application to electric bikes. Rated for 48V DC input, 15A nominal current.

Board is functionally partitioned into two parts - analog high voltage part and digital low voltage part. MOSFETs, drivers, driver power supply, buck regulator are on high voltage partition. DSP controller on a dock and signal conditioning is placed on low voltage partition. Ground planes seperated and joined through a zero Ohm resistor.

Hall current sensors provide isolated phase current sensing. A shunt based solution can also be considered as a cost effective alternative, at the cost of increased BOQ.

Isolated buck regulator provides power supply for DSP control stick. Control stick should be set to boot from flash mode. A soft startup on PWM signal is recommended.

IC FAN7388 is a boot strapping circuit for driving MOSFET gate driving. Boot strapped gate drives save cost compared to optical drivers by avoiding need for having additional isolated power supplies. However boot strapping comes with a host of other issues while operating at very high PWM frequencies. However I didn't had any issues till 100kHz switching frequency. Boot strapping diode and capacitor ratings should be properly selected. I recommend designers to go through the manufacturer design guides and application notes (AN-6076 and AN-9052) thoroughly to choose boot strapping circuit sub component.