why isnt my bootstrap circuit working? why doesnt the signal at the gate go to zero? I'm buidling a class D amplifier and this is the output stage.Could anyone suggest a solution.

 

Hello, are you sure all of your components are fine? Did you test them individually?

 

Hello,

The ucc27517 is a low side driver.
It can not provide a bootstrap.
For a bootstrap you need a high side driver.

Bertus

 

Hello,

The ucc27517 is a low side driver.
It can not provide a bootstrap.
For a bootstrap you need a high side driver.

Bertus

I know, but im trying to implement an external bootstrap circuit with it, just to see if i can. Is there something wrong here? Thank you.

 

Your PWM input signal is common to both ICs. To make the boost work I think you would have to raise the PWM input to the high-side IC.

 

U8's input is referenced to Ground.
U7's input is referenced to V_Out. (not ground)
C14 is too small. Parallel with a 10uF.

 

View attachment 368532why isnt my bootstrap circuit working? why doesnt the signal at the gate go to zero? I'm buidling a class D amplifier and this is the output stage.Could anyone suggest a solution.

You mean "amplifier" I guess?