is Kinetis suitable for Digital Powers(eg. 300Khz 1KW AC-DC)?

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

is Kinetis suitable for Digital Powers(eg. 300Khz 1KW AC-DC)?

1,121 Views
xqzju
Contributor I

I want to know if Kinetis is suitable for digital controlled powers?

 

from data sheet and references, I didn't find details of PWM,especially about time resolution capabilities.

 

when PWM=300Khz,  bits of resolution=? 

 

Is there any design notes about digital powers or inverters?

0 Kudos
3 Replies

780 Views
lukas
Contributor III

I study the flex timer capablities for class-d modulation and it seems

that the PWM frequency for max 16-bit resolution is:

 

100MHz/65535 = 1525Hz

for your task 300kHz

100MHz/300kHz = 333 it means some more than 8 bit resolution

 

Kinetis PWM is not high resolution. 

0 Kudos

780 Views
admin
Specialist II

Wouldn't the prescaler available in the flex timer's FTMx_SC register be useful here?  It can divide the clock as far as 128 which can get you more precision.  There should be other options available too, such as chaining registers together or lowering the core clock speed....

0 Kudos

780 Views
lukas
Contributor III

 

There are two parameters which goes against each other-  The PWM freq. is defined by modulo and source clock. If the MCU doesnt have some multiplier of sys.clock for PWM you must reduce PWM modulo for get higher pwm frequency and it decreases PWM resolution (resolution means the bit depth of modulatiom - number of levels which control the modulation from 0 to 100% of modulo).

 

0 Kudos