AduCM360 ADC conversion rate

Hi Ionut,

From the datasheet:

Also have a look at the ADuCM360/ADuCM361 Digital Filter Response Model from the product page.

It's an Excel file where you can modify the filter settings and see what conversion rates and settling times you're getting.

Regards,

Alex

Hi Ionut,

I just did a calculation in my head there and with 3.9kHz, the settling time is 3 conversions which works out at 0.768 ms, Also note at the bottom of table 16 there's a further delay of 0.256 ms every time you change channels because the ADC is restarted, so that gives you the 1.024ms.

Is the ~1ms good enough? You have 2 ADCs so that's effectively half of it as you can do 2 channels at once.

How many channels do you need to sample and in what time?

Can you do a few samples and then change channels so then you effectively gather more samples in less overall time?

Regards,

Alex

Hi Alex,

Thanks for the hint. I played a bit with the excel and with filter register values. The best I got is between 1 and 2 ms (i didn't put an exact timer for less than 1 ms interval). It seems that the fAdc is not the problem (3096Hz), but the settling time is (the excel shows 1.02 ms delay). I know next measurement would take less, but my application requires me to change adc config (input channels), so the settling time is delaying the whole thing every time.

Thanks,

Ionut

I am working on a safety related project, so both channels measure the same input- I need redundancy. Also, due to safety reason, I need to make some self-test during normal execution, so I would measure internal channels (Uadc, ChipTemp...etc), so I would change input channel on each run. So I guess I have to play around this 1 ms value.  It's tight for me as my app loop time is 20 ms, and I have to do 5 measurements (normal execution- no self test), compensation calculation. Also, the uc frequency is lowered to 1 Mhz (safety reason).

Ionut