Nachtrag zu den PWM-Frequenzen. Da arbeiten die Maxim-Leutchen mit mehr als dem doppelten als ich empfohlen habe:

"The best balance between performance and component size is achieved with an oscillator frequency at least ten times the maximum signal frequency (which is typically 20kHz). A 250kHz switching frequency, for instance, allows moderately sized 15μH inductors and 1μF capacitors for a 4 load, to set the output-filter bandwidth at 30kHz. Such a filter attenuates the switching frequency sufficiently while allowing most of the audio signal to pass unattenuated to the load. For the MAX4295, a 250kHz oscillator frequency and 4 load yields a THD of 0.3% and an efficiency of
85%"

Gruß,
Lev