ADS1230 Internal Clock drift

Hi Viktor,

If you take a look at Figure 17 on page 9 of the datasheet you will find a graph that shows Data Rate vs Temperature.  As the data rate is proportional to the internal oscillator you can see that the drift is about  0.1% over the range you are requesting.

Best regards,

Bob B

Hi Viktor,

You originally asked about oscillator drift performance and now you are asking about initial oscillator accuracy.  It is not clear to me as to how the drift data was taken as this was done some number of years ago.  It may have been based on an average of a small number of parts.  The actual frequency of the oscillator can vary quite a bit from part to part and the ADS1230 does not have a guaranteed specification as to oscillator performance. 

As far as the actual ADS1230 performance with the given electrical characteristics table conditions you will typically see 10sps at 25 degC.  The internal oscillator will vary by at least +/-3% over a range of parts from the nominal.  This range will vary the output by 9.7sps to 10.3sps and possibly more in some cases as this is not a guaranteed range of values.  If you add drift effects of the oscillator over the operating temperature range you may see the oscillator vary an additional 0.15%.  This is what the graph is showing. If you look at the graph for 25 degC and use that as a starting point you can see the typical drift characteristics above and below 25 degC. So the initial accuracy of the oscillator is much more dominant than the drift.  The drift data is within the initial +/-3% with the starting point at 25 degC.  If you need more oscillator precision you can use an external oscillator or the ADS1232 that has tighter oscillator specifications and lower oscillator drift.  The ADS1232 has a min/max specification of +/-3% for the oscillator.

Best regards,

Bob B