topic Re: KV4x PWM in Kinetis Microcontrollers

KV4x PWM

Vishesh45 — Mon, 27 Jun 2022 06:49:46 GMT

In KV4x Reference Manual there are two options to generate PWM

Chapter 37 : Pulse Width Modulator A (PWMA/eFlexPWM)

Chapter 39 : FlexTimer Module (FTM)

what is the difference between these two..??

with both i can successfully able to generate complimentary pwm signals with deadtime insertion for my full bridge power supply application.

I aslo need to read CADC.

found the document for " FlexTimer and ADC Synchronization for Field Oriented Control on Kinetis ".

is it possible to use ADC in sync with PWM(Chapter 37 : Pulse Width Modulator A (PWMA/eFlexPWM)) .....same as FlexTimer..?

Re: KV4x PWM

_Leo_ — Mon, 27 Jun 2022 22:27:48 GMT

Hi,

In a nutshell, PWMA allows you to increase the resolution of the PWM signal.

Regarding your second question, you can take as reference the application note AN5237.

I hope this will help you.

Re: KV4x PWM

Vishesh45 — Wed, 03 Aug 2022 04:28:52 GMT

Re: KV4x PWM

Vishesh45 — Wed, 03 Aug 2022 04:27:54 GMT

Hello,

Thank you for your response and valuable suggestion of application note AN5237, with the help of that i have successfully sync ADC with PWMA/eFlexPWM.

As you have mentioned in above comment "PWMA allows you to increase the resolution of the PWM signal"

I have found(on NXP site) and referd document Nano-edge placement of eFlexPWM on KV4x family .

As per the document it helps to increse duty cycle resolution by using fractional unit, so we can have duty cycle like 50.03125,
50.0625, 50.09325,50.125,…….50.96875.

my quary is regarding frequency resolution

in my application i have to use fix 50% duty cyle and have to change frquency as per the need.

Example : e PWM driving clock for KV4x is 100MHz

Total Timer Ticks : 1000 will generate frq 100000 Hz (100KHz)

Total Timer Ticks : 999 will generate frq 100100.1001001001 Hz

so 1 tick will produce 100Hz diffrance...and this diffrance increase as we go higher in frquency.

Is it possible to increase frquency resolution using fractional unit.??

orr it is just helps with duty cycle..??

in my application i need to vary frquency in range from 45KHz to 100KHz. I have no idea right now how much resolution i required but if it is possible to increase resolution like in duty cycle..,,,would like to go for it for precise performance.

Re: KV4x PWM

_Leo_ — Wed, 03 Aug 2022 14:48:20 GMT

Hi @Vishesh45,

Thank you for continuing to use our community.

This case has already been closed and marked as solved. Could you please open a new case with this new question in order to continue giving you support? This is also for the purpose of having a better Q&A follow-up.

Thank you in advance. Have a nice day!