A quick thought: Do you want to share what kind of testing you do on a new classD design. ( Maybe relevant for all amplifiers, but lets keep to D for now)?
My process is includes something like this (not always in order, - depending on the patience on that particular day)
Kind regards TroelsM
Edit: spelling
My process is includes something like this (not always in order, - depending on the patience on that particular day)
- Have simulations of the different circuit-parts so that you now what to expect when power on.
- Power up with slowly rising, current-limited PSU, - watch for stable oscillation
- Verify that current-draw is low. sometimes at a Vcc that is lower than design-target.
- Verify that gate-waveforms look fine and deadtime is sufficient, - always aim for larger deadtime before everything else is verified.
- Check clipping behavior without load and current-limited PSU, - watch for stability with varying degrees of clipping.
- Check distortion. Do not optimize anything yet, but verify that its in the right ballpark.
- Load with pure resistive 8Ohm and slowly turn up. Verify efficiency and that nothing gets hot.
- Load with inductive speaker-load and slowly bring to clipping. Watch for any sign of instability.
- Load with capacitor (1uf?) only and verify stability. Check with squarewave-signal and look for overshoot.
- If everything above is OK: check with a sineburst signal at max amplitude and maybe lower load-impedance to stress-test.
- test with full volume in dummy-load and watch for temperature-rise over time
- Check stability with high volume and connecting/disconnecting the load.
Kind regards TroelsM
Edit: spelling
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