What is the minimum frequency of S32K144

[youngyanliang]

Hi nxp team, 

MPN:FS32K144HFT0VLFR
We use FTM1_CH1 (pin-37) to drive the LED(Only VLPR mode need drive LED);
External 8M crystal and 32.768K OSC are used.

1.What is the minimum frequency that can be driven by this pin（VLPR mode）?
2.Can VLPR mode achieve the following frequency and duty cycle?

[Senlent]

Hi@youngyanliang

FTM can full-function run on VLPR mode only when source by SIRC, so the FTM source clock frequency is 8MHz default,and the max clock source prescaler is 128,

So the FTM max overflow time is :(63335-1) / (8000000Hz / 128) =1.048544S,I guess.

in this case,the LED frequency is so slow, is it necessary to use the FTM module?

BR!

     Jim,

[youngyanliang]

Hi Jim, 

  Thanks for reply.

  Do you have any suggestion?  GPIO as pseudo-PWM?

[Senlent]

Hi@youngyanliang

If it is in VLPR mode, just set your IO port to GPIO, and then use the timer to regularly output high and low levels.

BR!

     Jim，