Tool/software:
Hello TI
Our custom board connects to an external AMP (MCASP1 -> TAS2505->Speaker).
As far as we know, our arch is a Bridge mode and we expect to see the output of SPKP/SPKM wave form pattern are opposit , we measured at (1) & (2).
However, now we see them have the same pattern as below. May you provide an explaination? If it is an issue, how to fix it?
Hi Paul
As far as we know, our arch is a Bridge mode and we expect to see the output of SPKP/SPKM wave form pattern are opposit , we measured at (1) & (2).
This should be the Class AD modulation. And this modulation has large pop noise problem, we changes to Class BD modulation for the new developing parts.
Below picture shows a simple comparison for this two modulation type. Class AD reverse the PWM directly, so you would find a totally reversed P/M output. But Class BD reverse the audio input, then compare twice with the same Carrie, so not totally reversed PWM.
Hello Shadow
1. FYI, we measured SPK P/M output wavefrom, one by one with oscilloscope, SPK P + Commond ground of our custom board, and SPK M + Commond ground of our custom board.
SPK P/M both have the same parttern waveform.
2. May you guide how to check analog signal as in red line? when we play 2k , 5k tune song
