PCM5310 input / output levels

Hi, Mark,

Thank you for your interest in our products!

The answer to your question is kind of buried in the data sheet:

You'll notice the second line for VCCH... The device requires a 9V supply for the analog circuitry.

-d2

Don,

I was under impression that ADC (Vccad) 3.3V is determining factor for the input range and the Vcch (2^nd line) is analog voltage just for headphone amplifier.

Thanks,

Mark

Hi, Mark,

Good point!

There is mention of an internal LPF on the inputs, those must also contain a resistor divider to divide down the 2 Vrms input signal to a range compatible with the internal circuitry.

Although, I can't quite understand Fig 54, that seems to contradict the statement about an internal LPF... I would put it as the first thing before going to any active circuitry.

-d2

Don,

I was trying to find what is the VCCH?

Looks like this is just a voltage for the line output driver (page 6 line 5, page 95 “Line Output Pins”).

Mark

Hi, Mark,

Yes, I agree with you. I bet VCCH is just used to power the output op amps to get the 2Vrms swing.

-d2