stm32f429 timer pwm output signal as a clock

[liu yong]

Posted on July 06, 2017 at 05:53

I am working with the STM32F429 and we use the timer pwm output as the ads1271 CLK。 we get the wave as the picture show

We think CLK

quality

 is poor,so the sample rate is inaccurate. Any ideas ?

Thanks,

End.

[Zt Liu]

Posted on July 06, 2017 at 06:03

are you running your F429 with HSI or HSE?

[liu yong]

Posted on July 06, 2017 at 07:34

follow is the clock config

[waclawek.jan]

Posted on July 06, 2017 at 09:59

Review PLL parameters (jitter) in DS and compare to your requirements/measurement.

JW

[S.Ma]

Posted on July 06, 2017 at 10:21

First is to check which SPEED1:0 has been selected for the output pin. (output strength/slew rate)

[liu yong]

Posted on July 07, 2017 at 05:33

The main reason is my SPI interrupt function that recieve data from ADS1271  is inefficient. SPI lost samle points, after improve the spi ISR performance,now 4 x 102.4KSPS worked well for me.