I'm looking at some microcontrollers for power converters control (dsPIC33F and some ARM Cortex M3/M4 like the STM32F372CBT6 for instance) and I'm a bit worried by the limited number of PWM outputs (they top at around 8-11).
Since in the future my needs may change, I'd like to avoid finding myself in a situation where I need more PWM outputs. Therefore I'd like to know if it would be better to (in order to increase the number of available PWMs):
- Use multiple microcontrollers and communicate between them (via CANbus for instance), each microcontroller controlling its own PWMs
- Use external PWM generator modules via SPI/I2C (do they exist?)
- Any other microcontroller/DSP family supporting more PWM outputs?
- Creating as many PWM as needed using an FPGA? Not sure about this (IMHO probably over-complicated)
Why this many PWM? I don't think they are so many in fact ... With 10 PWM signals you could only control 2 H-bridges and a synchronous Buck converter.
Feel free to ask more questions if not clear enough.