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ADS7280: synchronized ADC two signals

dong andy
Prodigy 205 points
Part Number: ADS7280
Other Parts Discussed in Thread: ADS7142, , ADS8354, ADS8881

Our requirements:
1, ECG signal (0.01~150Hz);
2, Heart sound signal (20~2KHz);
3, These two signal need to be synchronized ADC;
4, Just ADC these two signals, No need DSP etc;

My thought, these two signal have ADC at the same sample rate (125KHz) and then
downsample to the different sample rate.

Two options ADC chips:
1, MSP432, It has 24 chs 14bit (1MSPS) ADC;
2, ADS7142;
3, ADS7280;

Can you give me better solution or suggestion?

Thanks,

Andy

  • 0
    TI__Intellectual 1205 points
    Hello, Andy.

    Options 1 and 3 above are not simultaneous sampling, and Option 2 is only 12 bits. Plus, Option 2 has an I2C interface, which is not fast enough to get data out at 125ksps. Would you like to use something like an ADS8354? That one is 2 channel, simultaneously sampled, 16 bits, differential input, at 700ksps max.

    Or maybe ADS8881? That one is 18-bit 1Msps with differential input.

    Is simultaneous sampling a key feature? With a 1Msps 2-channel mux’ed input ADC, each sample could be separated by only one microsecond.

    There are many options here.
  • 0 in reply to Bryan McKay
    Prodigy 205 points
    Thanks, Bryan.
    Yes, Simultaneous sampling is a key feature. External channel mux is second choice if there are NO better simultaneous ADC. I will try to use ADS8354 to do some test.
  • 0 in reply to dong andy
    TI__Intellectual 1205 points
    Andy:

    Thank you for your question. The ADS8354 has features that will be more along the lines of what you are looking for. Please let us know if you have any more questions as your project progresses. We will be happy to help or make further suggestions.