FTM used PWm in s32k1

[jingfang]

Is it possible to output 4 PWM phase shift 90、180、270?

[JRoberto]

Hello @jingfang 

Yes, it is possible.
You can use one of the S32k1's FTM instances and create 4 PWM signals in 4 channels working as pwm in combine mode (example Channels 0,2,4,6).

This Application Note can be helpful.

https://www.nxp.com/docs/en/application-note/AN5303.pdf

[jingfang]

Thanks a lot~

Is there a frequency limit? I find eMIOS0: 6 channels in PWM mode @ 20 KHz in S32K3,eMIOS1-2: 8 channels in PWM mode @ 400 Hz,but not find S32K1'FTM.

I want use S32K116,use Modified Combine PWM Mode to realize,but I find S32K116's has some limit,

Whether these restrictions make a difference?

[JRoberto]

@jingfang 

The max achievable PWM frequency is governed by the SYS_CLK and other factors like the PWM mode, PWM resolution, AC electrical specs on the pins.

If you set the Clock Prescaler to 1:1, then the count increments once per clock tic. Then you can use the formulas below to calculate the frequency:

First we need to calculate the PWM period in tics:

* For an Edge-align PWM mode(EPWM): Period  = MOD – CNTIN + 0x0001

* For a Center-align PWM mode (CPWM):  Period  = 2 × (MOD − CNTIN)

Frequency = 1 / ( (Period in tics) * ( 1 / FTM’s CLK_Freq) )

So the frequency formula would be:

Frequency = 1 / ( (Period in tics) * ( 1 / FTM’s CLK_Freq) )

You can review The AC electrical specifications at 5V range on the table 23 from the Reference Manual

Best Regards