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[on:]

I took a brief interest in this ADC due to its low cost and high performance. For example, it could be really nifty for power measurements since it offers oodles of sampling speed, a built-in PGA, 6 channel MUX for each of the two built-in 24-bit ADCs, etc.) All in a package that has a reasonable cost and which which can be interfaced with easily via I²C.

But the documentation could be better and one aspect in particular has me stumped: Although this is a unipolar ADC design, it does not allow DC inputs. All external pins require a de-coupling pin but there is no differential input as I would have expected. How is this supposed to work?

[Reply #1 on:]

Its an I2S bus audio ADC, needs 3 accurate clocks, don't even think about interfacing an Arduino to it!

The lowest rate it can handle is 16kHz sample rate 64 bit clocks per sample,  ie 1024kb/second (and you have to feed it an 4.096MHz clock).  I've interfaced to I2S devices on the Propellor microcontroller but that has 16 clock units each with a phase-locked-loop and capable of 40MHz...

Don't confuse I2C and I2S.

All these I2S devices are for audio, they all do high-pass filtering to remove the DC component.

[Reply #2 on:]

Silly me. I saw the reference to I²S as well but when the datasheet mentioned that the device could be configured using I²C, I thought it might work. I have since realized that while one might be able to configure the unit via I²C (PCM1851A) or SPI (PCM1850A) that the output is still  I²S since there are no registers to query.

Thanks for the help!