Can I use the FILTA pin as the reference voltage for the input amplifier?
Hello!
I 'd like to connect an inverting amplifier on the operational amplifier to the ADAU1701 ADC input without a capacitor. Is it allowed to use the FILTA pin as the reference voltage for the amplifier? I did not find any mention of such a possibility in the documentation.
Serg.
Audio Signal Processors
SigmaDSP Audio Processors
adau1701
Hello,
You can use pin 40 (CM) for a 1.5v reference, provided it goes only to your op amp noninverting input (as you likely wish to do). This option is described on page 13 of the data sheet.
Best regards,
Bob
Thank you so much!
Serg.
Hello, SergAvdjushin,
I usually like to buffer this CM voltage with an op-amp in the voltage follower configuration. This way you prevent crosstalk between channels and you do not load down the internal CM voltage. But if the application is cost sensitive then you can use it as a reference for a couple of op-amps as described in the datasheet.
Dave T
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