2012-10-26 04:43 PM
Hi
We are using the STM32L151. I want to use an analog input to control the duty-cycle of a PWM output. I am using DMA, so the CPU has no intervention since I will be running the duty-cycle updates fast. However, I need the ADC value to control the duty-cycle of PWM channel 1 and have another channel (PWM channel 2) with the same duty-cycle, except it needs to have a deadtime before and after the reference dutychannel. (seehttp://www.electronicsdesign.dk/tmp/deadtime.pdf
for how the signals should be)
The reference duty-cycle will be center alligned. Is there a way to do this? (sorry if this is a basic question) If this cannot be solved in SW, I guess I could use two ADC inputs, a seperate DMA transfer to make the individual PWM output, and add an offset voltage to the second ADC input to let the PWM output of this channel have a certain deadtime, but that is not very desirable, since it needs HW to configure the deadtime. Thanks Klaus #adc-duty-cycle-dma-deadtime