The the noise floor image in the original post is with the output of the supply is connected to a resistor load. I see the same subharmonic noise when the output is connected to an inductive load.
The gate drive signals are driven by an off-the-shelf isolated IGBT driver module. This module is...
The subharmonics do follow the triangle frequency. I have already looked a little into the comparator/PWM generator, and I did not find anything conclusive. It sounds like it might be worth digging a little deeper into this part of the circuit to be certain that this is not the source of my...
I do not think that aliasing is an issue with my FFT measurement. The data for the FFT is sampled at 192kHz.
The 2.25kHz, 4.5kHz, etc. subharmonic frequencies in the noise floor do not seem to be an alias of any meaningful frequencies with this sample rate. I might be miscalculating something...
I have a design for a DC-AC full H-bridge inverter implemented with IGBTs that is functioning quite well, but there is one problem that I am having trouble solving. I am seeing spikes in the FFT of the output noise floor that appear to be subharmonics of the PWM frequency.
I am measuring the...