This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

ADC Recommendations for speed data adquisition.

Other Parts Discussed in Thread: ADS1018, ADS1118, ADC122S101, ADC122S051, ADC121S051

Hi,

I need help to choose the best option of one ADC. My application is in charge of the speed acquisition of 6 thrusters.

Requirements:

1. SPI bus.

2. Analog Signa to acquirel: 0 to 5 Volts.

3. Periodic Acquisition: 10 msec.

4. I would rather two ADCs for each IC due to the fact I'm going to need 6 ADCs, and so with three ICs will be enough.

Thank you so much. Best regards.

in the acquisition

  • Oscar,


    What resolution are you looking for?

    With a 10ms acquisition period, you might be looking for a delta-sigma type of ADC. You mention that you are measuring 6 thrusters. Can you describe what it is that you are measuring? Does it require any other circuitry? Do you need any gain, or buffering?


    Joseph Wu
  • Hi Josep,

    The resolution is 12 bits. I only need to measure an analog signal from 0 to 5 Volts.

    Thank you very much. Best Regards.

  • Oscar,


    If you only need 12 bits, I'd recommend something like the ADS1018. It uses SPI, has 12 bits of resolution and has a data rate that can achieve the 10ms data period. Note that there is some digital filtering that may limit the signal bandwidth, so it might be best to go to a higher data rate and use the single shot mode to time the conversions. It also has an on-board reference.

    Look through the datasheet, see if works for you, and you can respond with questions. If you need higher resolution, or if the input range doesn't match up with one of the gain ranges that is available, then the ADS1118 might work as well.


    Joseph Wu
  • Hi Josep,

    Thank you very much for your quick answer. I was thinking that I could use this ADC122S051 due to the fact there are compatible ICs with less resolution: 10-bits and 8-bits and I could raise the rate to 1MSPS with another IC [ADC122S101] with the same package.

    What do you think about this option? The only drawback I've found it's the speed of the bus SPI only 8MHz I would like at least 20 MHz.

    Do you know If there is another fast option?

    Thank you so much. Best Regads.

    the only drawback I've found

  • Oscar,


    I'm sure the ADC121S051 is a fine device, but I don't know it very well. If you've read through the datasheet and checked the specifications, it should work for you.

    Originally, you mentioned a data period of 10ms which works to be 100 samples per second. Do you really need 200k samples per second?


    Joseph Wu
  • Hi Josep,

    Thank you for you reply. It's possible the need of a fast adquisiton, but I don't know how much.