Question regarding ADC's and SPI

Hi, I recently ran across the TI adc122s625 ADC, which seems to be quite ideal for my power measurement application. What I like about it is that it offers 12 bits of resolution, 2 concurrent differential inputs, and very high clock rates on demand (that is, every time you select the chip, it does another conversion, up to about 120ksps at a 4MHz SPI bus speed). The sampling rate can also be controlled by simply turning the CS pin on and off on demand. The ADC is set up for 5VDC operation, so no voltage translators are needed.

The use of a chip with two converters that work concurrently also seems advantageous since it virtually eliminates phase lag on account of the voltage and current being measured consecutively. There likely is still some lag (the coils of the transformer and the current sensor are not the same) but said lag is now minimized from a measurement point of view.

Besides the 12-bit resolution and fast speed, I also really like that I can sample the output from the voltage transformer directly. The current transformer produces a biased signal, but this ADC also has a suggestion re: removing said bias from the input signal in its datasheet. Does anyone have experience with units like this on an Arduino? Are there libraries for similar chips? A search here for the ADC showed no hits...

Looks like a pretty nifty chip. And a low power shutdown mode... Perhaps you get to write the library for it ;)

Nice chip, but it looks like your on your own with the code.


No worries. I thought I'd try it out with some previous work that Crossroads did. To me, only the timing looks critical, i.e. waiting exactly 32 SLCK cycles before listening for the four bytes of data and pulling the CS pin high again. But I really like this chip so I'll give it a whirl.