FlexTimer max frequency when all channels are used?

[bert_haj-ali]

Hello,

I am using a development board that has the K66 processor on it and it is Arduino-compatible; it's called the Teensy 3.6. I am programming it through the Arduino IDE.

I want to generate 100kHz phase-shifted pwm signals for a full bridge converter and 2 more pwm signals for the secondary side synchronous rectifiers using FlexTimer, FTM0. I managed to do that successfully following the application notes AN4410 and AN5142. However, when I use all channels of FTM0, the frequency drops to around 90kHz and if use only 4 channels, it goes back up to 100kHz.

Does anyone know the reason for this?

Is it hardware limitations or something wrong in the code?

The code is attached.

Thanks in advance.

[Alexis_A]

Hi Bert,

I don't know about the Arduino IDE and this board but I tried to reproduce your issue using MCUXpresso and the FRDM-K66 and could enable 7 FTM channels without issues. If you're interested in this IDE here's the link:

MCUXpresso IDE|Eclipse-based Integrated Development Environment (IDE) | NXP 

Also here's the link to download our SDK's:

Welcome | MCUXpresso SDK Builder 

Best Regards,

Alexis Andalon