If possible please, I have some questions regarding voltage regulators for digital and analog supply on dual WM8741.
I have used 2 x LM1086 for 3.3v and 5volt supply. I used the original PCB the LM1086s were mounted on to preserve the stability that a ground plane design would have.
With no Wave IO input I2s to DAC,(which I assume is in a standby state) both output rails are relatively quiet and stable on a Tektronix oscilloscope with about 2mV peak to peak noise.
A very different story once the the Wave IO is connected, with noise levels with many high frequency components taking the noise to at least 30mV.
Both digital and analog are effected.
Am I expecting too much with 2 x WM8741 operating?
The rails are well decoupled, especially on the original regulator boards with very low esr ceramic thick film capacitors.
What would you consider acceptable noise levels in operation?
Thanks, Brian.
I have used 2 x LM1086 for 3.3v and 5volt supply. I used the original PCB the LM1086s were mounted on to preserve the stability that a ground plane design would have.
With no Wave IO input I2s to DAC,(which I assume is in a standby state) both output rails are relatively quiet and stable on a Tektronix oscilloscope with about 2mV peak to peak noise.
A very different story once the the Wave IO is connected, with noise levels with many high frequency components taking the noise to at least 30mV.
Both digital and analog are effected.
Am I expecting too much with 2 x WM8741 operating?
The rails are well decoupled, especially on the original regulator boards with very low esr ceramic thick film capacitors.
What would you consider acceptable noise levels in operation?
Thanks, Brian.