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Original question:

ADS131E08: Can we multiplex each channel?

ADS1258: Why the device can achieve 23.7kSPS/channel with 125kSPS speed for fixed channel?

Howard Zou
Genius 12365 points
Part Number: ADS1258

Hi,

since this device has 16 channel.

Why the sample speed for auto scan is higher than 125kSPS/16?

And why doesn't this device need to discard the first several data when signal switches from channel 1 to channel 2(step change).

In other delta-sigma ADC, we have to discard the first several data when there is step change in the input signal.

  • 0
    Prodigy 100 points

    Hi Howard,

     It’s not higher, it’s much lower since you have to settle the digital filters among other things.

    So the data rate in auto scan is “23.7kSPS/Channel” where channel is the number of active channels in the auto-scan. For 16 active channels the data rate would be 23.7/16 = 1.48125 ksps.

     PG.20:   “(3) In Auto-Scan mode, the data rate listed is for a single channel; the effective data rate for multiple channels (on a per-channel basis) is the value shown in Figure 42 and Figure 43 divided by the number of active channels in a scan loop”

     Mauricio Vier