Several weeks ago, I asked for your help in selecting a motor of a roadtest. Here's the blog: Seeking Assistance in Selecting a Motor for a Single-Phase Inverter Roadtest


With your input and help, I went back to the sponsor and we selected a motor.


So, here is what each roadtester will receive:


one Fan motor  (The sponsor selected this)


one RDK-872 - Reference Design Kit for BridgeSwitch (70 W Single-Phase Inverter Using BridgeSwitch for Fan Application)


one RDK-873 - Reference Design Kit for BridgeSwitch (30 W Single-Phase Inverter Using BridgeSwitch Motor Driver)


The motor drivers need an MCU board.


The sponsor gave me some recommendations for MCU boards. Here's what they said:


"Preferred MCU core is CortexM0. A good reference with minimum MCU resources below. One would need these resources not only to run the MC SW but also implement some debugging capabilities with FAULT, communication to PC, etc. Its better to start bigger on resources. The 1-phase SW examples on our website run on CortexM0 from IFX and are in DAVE. One can take the SW and port it to IAR where there is support for both NXP and Renesas."




Minimum Requirement 1-phase BLDC


MCU Core


Flash / SRAM (KBytes)

20 KB /8KB

For application development larger memory capacity is needed

Execution Performance (MIPS)


Performance requirements also includes CPU clock frequency, latency of Flash and SRAM


1 (96MHz clock)

Critical in generating PWM clock with at least 20KHz carrier frequency and 11 bit of resolution. Faster timer clock delivers higher PWM resolution = better precision and controller performance.


12-bit / 11 ENOB* @1Msps, 4-6 channels

# of ch. should allow the scanning of current / voltage as needed by the chosen control algorithms.

Analog Comparators

3 channels, 100ns response time

Needed for proper operation of the zero-cross detection when operating in trapezoidal commutation mode

Bridge Switch FAULT

2 x GPIO

Bi-directional GPIO (open drain)


Debug interface

Required for debugging purpose


Min 6 inputs, 4 outputs

Sampling of the HALL sensor state. Alternative as command interface to the UART and the Host.

UART - Communication

Min 115.2Kbps

The UART interface is required for host communication


I'd like to get a recommendation of an MCU board for this roadtest. The sponsor mentions both NXP and Renesas. But I am open to other possibilities such as Infineon or other manufacturer.


I'd appreciate any suggestions in the comments section below. Thanks.


Randall Scasny

RoadTest Program Manager