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ADS1256: Max sample rate when using all channels

Matthew Bavier
Prodigy 320 points
Part Number: ADS1256


I have a customer that is interested in the ADS1256 however they were unable to determine the maximum sample rate for each channel if all 8 are being used. They were also wondering if this sample rate or resolution would be limited by the part only having a single converter. 

What is the max sample rate that can be achieved with all 8 channels in use and how does the single converter affect this?

  • 0
    TI__Guru 54426 points

    Hi Matthew,

    Figure 19 in the ADS1256 datasheet shows the conversion sequence for cycling the input multiplexer, and time t19 is shown as the time it takes to convert a single channel using this sequence.

    Table 14 gives t19 for each data rate. As you can see, at 30 kSPS (the max data rate using CLK = 7.68 MHz), t19 is 4374 Hz or 0.22mus. So to cycle through all channels would take 0.22*8 = 1.76 ms.

    You can increase the CLK rate up to 10 MHz and the data rates and conversion times will scale accordingly. This will enable the customer to get the fastest overall channel scan time.

    -Bryan