I'm changing a design from AD7799 to ADS1220 for the higher speed conversions.
The 7799 takes a longer time to convert if you switch input channels.. is this the case with the ADS1220?
The target is to sample 2 channels at 1 kHz.
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I'm changing a design from AD7799 to ADS1220 for the higher speed conversions.
The 7799 takes a longer time to convert if you switch input channels.. is this the case with the ADS1220?
The target is to sample 2 channels at 1 kHz.
Hi OXO,
The ADS1220 uses an FIR filter that is single-cycle settling. That means the first conversion following a configuration change has fully valid data. Running in turbo mode will allow a data rate that is approximately 2ksps. Any latency will be relative to the retrieval of data and writing the new configuration. So you can come very close to getting 2 channels of data every 1 ms using the internal oscillator.
Note that I said approximately 2ksps. The actual conversion times are listed in Table 11 on page 28 of the datasheet as number of clock cycles. Also note that the internal oscillator may vary some over temperature and from device to device. If precise timing is required, then I would suggest using an external oscillator to clock the ADS1220. If you need a slightly faster output rate, you can use a faster clock (up to 4.5MHz). The clock ratio relative to 4.096MHz is directly proportional to the change in data rate.
Best regards,
Bob B