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There is a 5.6V peak on the rising edge using STM32F103 TIM1 PWM output pin

Question asked by Wang Sky on Jun 15, 2017
Latest reply on Jun 15, 2017 by Clive One

Hi everybody!Recently I found a strange phenomenon that there was a peak on the rising edge when I using the TIM1's 4 chanels to be PWM output mode.And the maxium peak voltage can reach to 5.6V measured by the oscilloscope.But the maxium voltage supplied for the MCU was just 3.45V measured by the same oscilloscope.

So where was the 5.6V peak voltage from?Please help me!

Environment:

1.MCU model:STM32F103VET6

2.Core clock:72MHZ

3.Used TIMER:TIM1

4.Timer Mode:PWM output mode

5.PWM frequency:100Hz

6.Duty cycle:50%

7.PWM driver load:No load

8.PWM output pin configuration:GPIO_Output_AF_PP

 

The peak of the PWM

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