PCM2906CEVM-U: Purpose of the OP amp circuit

The op-amp circuit serves as a LPF for analog input and output (CH1/2) 

Hi Team

I have other questions as follows：

1. What is the function of D001?  To prevent current reflow from Vcc1 or other reasons?

2. Can we remove the D001? 

3. Can we change capacitor form electrolytic capacitor to MLCC for the design?

     Does this change cause design concerns?

Thank you.

Darren

Hi,

I am out of office today for US holiday so please be patient as responses may be delayed.

Thank you for your patience.

Regards,

Hi,

1. When power supplies turn off, the diode discharges the capacitor, so it's empty when power supplies turn on again the next time.

2. I recommend following circuit connection shown if using LDO or EVM for better performace. However, a diode isn't needed for circuit design, note typical configuration 1&2 in datasheet

3. The capacitor shown in the diagram is by default a 10uF electrolytic cap, not shown on EVM user guide but shown in figure 36/37 of d/s.

Hi,

Here are some more questions :

1. For the typical configuration 1&2 in datasheet, I note the difference is using external or internal voltage regulator, will this affect performance?

2. Why should C003 be discharged at the next power-on if using LDO or EVM for better performace?

3.Why use electrolytic cap for input & output of amplifier?   Does this mean that the electrolytic capacitor has a better filtering function than MLCC?