Description

This reference design is a power stage for brushless motors in battery-powered garden and power tools rated up to 1 kW. The power stage operates from a 10-cell lithium-ion battery with a voltage range from 36 to 42 V. The design uses CSD18540Q5B NexFETs featuring a very low drain-to-source resistance (RDS_ON ) of 1.8 mΩ in a SON5x6 SMD package: which results in a very small form factor of 57 × 59 mm. The three-phase gate-driver DRV8303 is used to drive the three-phase MOSFET bridge: which can operate from 6 to 60 V and support programmable gate current with maximum setting of 2.3-A sink / 1.7-A source. The power stage can be configured for a single-shunt or three-shunt current sensing. The design supports sensorless control for brushless DC (BLDC) and permanent magnet synchronous motors (PMSM) using trapezoidal control or field oriented control (FOC). The C2000™ Piccolo™ LaunchPad™ is used with the power stage to implement InstaSPIN™-FOC using the motor current and voltage feedback. The corresponding test report evaluates the thermal performance of the board and overcurrent protection features such as cycle-by-cycle control and latch control of the DRV8303.