Hello Guys, I am creating a class D audio amplifier using 2 outputs from a 3 phase bridge. The 2 PWM outputs (R and Y) are at opposite polarity to provide a differential voltage at the output.

My switching frequency is 10KHz and the output frequency response showed a cutoff frequency of 400Hz. What does this indicate?

Also, how can i improve the performance of the audio amplfiier? Is it by increasing switching frequency? Reducing deadband time? or anything else?

 

The switching frequency should be a least 10 times the highest audio signal frequency of interest.

Since you didn't post your complete circuit I can't tell why your frequency response is 400Hz.

 

This might help -

https://www.google.com/url?sa=t&rct...tutorial.pdf&usg=AOvVaw269YxhSpC5SN0_jy-m1PAC

http://pages.silabs.com/Improving-Class-D-Audio-Amplifier-Design-LP.html


Regards, Dana.