ADS1232: performance data required

Hi Mahendra,

Most of what the customer is asking for relates to AC specifications and performance of an ADC. The ADS1232 measures signals at or very near DC (temperature, bridge sensors, etc). The ADS1232 is an oversampling Delta-Sigma converter that includes a Sinc4 digital filter with a filter cutoff frequency less than Nyquist. On page 16 of the ADS1232 datasheet you can see the frequency response of the oversampling frequency (modulator rate) in Figure 30. In Figure 31 you can effect of the Sinc4 digital filter. Passing an AC signal to measure the requested performance attributes wouldn't be all that useful as the outcome would change considerably depending on frequency.

What matters most is repeatability not affected by noise. The noise performance is given in Tables 1 through 4 on page 5 of the ADS1232 datasheet. Also on page 5 are the calculations for ENOB and Noise-Free bits. These calculations are from direct DC measurement as opposed to a specific AC signal relative to noise and distortion (SINAD). In the typical characteristics plots starting on page 8 you can see some time domain plots and histograms. ENOB relates to 1 standard deviation and Noise-Free relates to peak-to-peak noise.

If the customer requires the requested information it may be that they do not understand this type of ADC (low data rate oversampling ADC compared to a SAR ADC) or perhaps the ADS1232 is not the correct choice for the application. If you have further information regarding the application I may be of more help.

Best regards,
Bob B