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ADS131M08: ADS131M08

Part Number: ADS131M08
Other Parts Discussed in Thread: ADS1235, ADS1230, ADS1231, ADS124S06,


I'm going to use ads131m08 for reading 8 load cells in my application. I want to use this IC due to its ability to read 8 channels simultaneously.

Load cell specification:

Rated Output: 2mV/V

Bridge Resistance: 700 Ohm

There are a couple of questions:

1-Is Ads131m08 suitable for reading the Wheatstone bridge(load cell)?

2-I couldn't find the ads131m08 voltage reference max voltage. is it 1.2V or it could be 3.9V?

3-What is your recommendation for excitation voltage(max can be 5V) and the reference voltage. Can I have 5V for excitation and 1.2V for reference voltage?


  • Hello, 

    We've had other customers ask us for similar implementations. 

    1.) It was not necessarily meant for bridge applications, like the ADS1235, ADS1231, or ADS1230 type products are, or even devices like the ADS124S06 that still make interfacing with a bridge very convenient.  That said, it may work for your bridge application since simultaneous high channel counts are tougher to create with the other products. 

    2.) The reference voltage should be 1.2V and the range is from 1.1-1.3V.

    3.) Yes, but you'll need to divide down your excitation voltage and feed it into your VREF voltage to create a ratiometric system. You'll also want to operate the ADS131M0x in at least a gain of 8V/V for the higher input impedances and you'll still likely need a low-noise pre-amp to gain the signals up into the proper range for the ADS131M0x and overcome the noise front-end noise. See example below: 

  • Hi Collin,

    Thanks for your reply and information.

    What happens if I use a separate precision regulator for the excitation voltage and ADC reference?
    I mean use two precision regulators. 

    1- First: 5V to 1.2V

    2-second: 5Vto 3.3V(for excitation)

    Actually, I'm using ADS131M08EVM Board and I get a good result without using any amplifier.


  • If you choose to use two reference IC's instead of dividing down the main bridge reference, then your measurement will not be ratiometric since the bridge and reference are not derived from the same source.  Admittedly dividing down the reference introduces it's own gain errors and potential offset drift differences with the op-amp but it's a more common approach and is often done with +15V bridge excitations going down to +5V ADCs.