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I looked at the schematics of the PDM amplifier chips linke and I am puzzled why they put a DAC in front of a class d amp. Can you just digitally amplify the PD
by riedel 3y ago
I looked at the schematics of the PDM amplifier chips linke and I am puzzled why they put a DAC in front of a class d amp. Can you just digitally amplify the PDM out and then do the low pass trick. I thought that was all the class-d amps are doing.
- iamflimflam1 3y agoReading up on the ICs the value they add is in the clever modulation schemes they use to avoid needing filters on the output and EMI. I guess you can't really trust the raw PDM output from an MCU which might not be very well designed or shaped. Maybe better to convert back to analog and then apply whatever secret sauce you have to make the class D amplifier work really well.
- mastercheif 3y agoHighly recommend reading the various interviews and papers by Bruno Putzeyes. He’s been pushing the state of the art in PDM / PWM / Class-D amplification for the last 20 years or so. Here’s a white paper of his specifically about direct PWM amplification. https://www.researchgate.net/publication/242013327_All_amplifiers_are_analogue_but_some_amplifiers_are_more_analogue_than_others https://www.researchgate.net/publication/242013327_All_ampli...