18V/400W High Efficiency (98%) Compact Brushless DC Motor Driver Reference Design with Stall Current Limit

TIDA-00772 is an 18A RMS driver for three-phase brushless DC (BLDC) motors in power tools powered by 5-cell Li-ion batteries (up to 21V). The design is a compact 45 x 50 mm actuator that enables sensor-based trapezoidal control. The design uses a discrete compact MOSFET-based three-phase inverter that delivers 18A RMS continuous (60A peak for 1 second) winding current without the need for any external cooling devices or heat sinks. The gate driver's slew rate control and charge pump ensure maximum inverter efficiency (>98% at 18V DC) with optimal EMI performance. Cycle-by-cycle overcurrent protection prevents large stall currents in the power stage, and the board can operate in ambient temperatures up to 55°C. The small form factor allows for flexible plate placement, the high efficiency allows the battery to last longer, and the 60A peak current capacity delivers high instantaneous peak torque in power tools.

characteristic

• ● Operates from 5V to 21V (5-cell Li-ion battery) with up to 18A RMS continuous (60A peak for 1 second) winding current without heatsink or airflow
• ●PCB compact size: 45mm x 50mm
• ● Optimal inverter efficiency (>97% at 10.8V) and EMI performance by using low RDS_ON NexFETs along with slew rate control and charge pump functionality of the gate driver
• ● Cycle-by-cycle overcurrent protection, response time is less than 1us, and short-circuit latch protection is provided through VDS sensing
• ● Breakdown protection, under-voltage protection, over-temperature protection and rotor stall protection