TIM1 PWM BK and BK2 strange behavior

[PKurz.1]

Hello,

I configured TIM1 as shown in the attached image:

Everything works as expected

I am controlling an inductive load which oscillates heavily after the PWM is turned off. I therefore decided to immediately short the low-side MOSFET (CH1N) to ground if a BREAK or BREAK2 signal is received. I set the Channel Idle State to SET. And the behavior of BREAK/BREAK2 changed.

As seen in the close-up::

A low state on BK2 does not set a high state on CH1N. Should BK1 and BK2 not be ORed?

[PKurz.1]

any suggestions ?

[Bubbles · Accepted solution]

Hi @PKurz.1 ,

first suggestion is not to reply on your own question. People actively looking for unanswered question will miss it. There's a break related AN4277, take a look if you can find an answer there.

How to use PWM shutdown for motor control and digital power conversion on STM32 MCUs - Application note

My first impression from your screenshots is that you are perhaps having problems with dead time insertion.

Kind regards,

Jarda