1. Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
    Dismiss Notice

One Signal, Multiple ADCs

Discussion in 'Electronic Projects Design/Ideas/Reviews' started by Quercus, Sep 24, 2017.

  1. Quercus

    Quercus New Member

    Joined:
    Dec 3, 2015
    Messages:
    22
    Likes:
    0
    My project must use multiple ADCs to sample many input signals, but each ADC also needs to sample one common signal. So the common signal will be connected to approximately 8 different ADCs. Most are the MCP3208, and one is the AD7856 (a high precision, high speed chip). Will this present any problems or can all the ADCs happily sample the same signal without interfering with each other?

    Thanks.
     
  2. ronsimpson

    ronsimpson Well-Known Member Most Helpful Member

    Joined:
    Apr 17, 2007
    Messages:
    7,253
    Likes:
    961
    Location:
    Loveland, CO USA
    I think you have 8 MCP3208 and all "input-0"s are connected together.
    Microchip talks about using a low impedance source to drive the inputs. When the ADC reads there a small amount of current going in/out of the input. Also each ADC will be sitting on a different ground. (PCB layout problems)
    I think you should put a RC on each "input-0" very close to each ADC. 1K and a small cap.
     

Share This Page