A ADP2303 provides the power of an AD1974 @ 16kHz in my circuit. But when I listen to the audio a weird tone is hearable. This tone seems to be introduced by the ADP2303 (the tone changes when I change inductor value).
The current setup is: Vin = 12V, Vout = 3.3V, Vd = 0.3V, L=3.3uH, Cout = 4x47uF X5R + 1x 100uF tantalum. I also tried without the tantalum capacitor but this seems to increase the ripple.
According the datasheet a 30% Iripple with a Iload of 0.15A will require a 270uH inductor but the inductor value should not be higher than 15uH.
Does anybody have any suggestions/ideas?