36V, 32A power stage for BLDC motors with cycle-by-cycle stall current limiter

This reference design is a power stage for brushless motors in battery-powered garden tools and power tools rated up to 1 kW, powered by a 10-cell lithium-ion battery with a voltage range of 36 to 42 V. This design uses 60V N-channel NexFET(TM) with ultra-low drain-to-source resistance (RDS_ON) of 1.8 mΩ in a SON5x6 SMD package, resulting in a small 57 × 59 mm PCB footprint. This design uses a three-phase gate driver to drive the three-phase MOSFET bridge, which can operate from 6V to 60V and supports programmable gate current with a maximum setting of 2.3A sink/1.7A source. The C2000™ Piccolo™ LaunchPad™ LAUNCHXL-F28027 is used with this power stage and implements 120-degree trapezoidal control of BLDC motors via Hall sensors in software. The gate driver's cycle-by-cycle current limiting feature limits the maximum current allowed in this power stage to a safe level, thereby protecting the board from overcurrent issues caused during motor shutdown.

characteristic

• ● 1kW power stage for brushless DC motors with Hall sensor based trapezoidal control implemented on TMS320F28027 MCU
• ● Powered by 10 lithium-ion batteries with a voltage range of 30V to 42V
• ● Provides up to 32A RMS continuous motor current at 400 LFM airflow
• ● This power stage uses CSD18540Q5B 60V/400Apeak, 1.8mΩ RDS_ON, SON5x6 packaged MOSFET to achieve a small PCB footprint of 57 × 59 mm
• ● Uses the DRV8303 three-phase gate driver, which operates from an input voltage of 6 to 60 V and supports programmable gate current with a maximum setting of 2.3A sink/1.7A source
• ● Hardware cycle-by-cycle overcurrent limiting using configurable thresholds for motor stop protection
• ● Provides inductive feedback of individual phase voltage, DC bus voltage, DC bus current sensing and low-side current sensing for each phase to achieve sensorless control
• ● Powers the MCU through a 3.3V/0.15A buck converter based on TPS54061
• ● Designed to operate in ambient temperatures from –20°C to 55°C