ADS1262: Clock Source and Data rate calculation

Silvano Ghilardi

Part Number: ADS1262

We need to get several data and also set several DAC at a synchronized clock of 50Hz. We would like to do it by generating a central clock (e.g. 7.34MHz) and clock the ADS1262 with it.
Now we need to know the exact resulting data rate of the ADS1262 based on this central generated clock.

How can we calculate it? Is it correct, that we can start with our input clock (e.g. 7.34MHz), this will be divided by 8 (always internally of the ADS1262) and than depending of the setting of the ADS1262?
(see page 45, 9.3.9 and 9.3.10)

What about the internal digital filters?

Thanks

Silvano

over 7 years ago

0 Christopher Hall over 7 years ago

TI__Mastermind 44790 points

Hi Silvano,

It shouldn't be any issue to clock the ADS1262 with a 7.34 MHz clock instead of a 7.3728 MHz clock. The ADS1262 is specified to work with clock frequencies between 1 and 8 MHz.

All of the datasheet listed data rates assume that you are providing the nominal 7.3728 MHz clock, so you'll find the output data rates will be a bit slower than specified with the slower clock. The scaling is linear, so the nominal 100 SPS data rate will actually be (7.34 / 7.3728) * 100 = 99.5 SPS.

You can double check the data rates for other ADS1262 clocks and modes as well by downloading the ADS126X-CALC-TOOL:

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ADS1262: Clock Source and Data rate calculation