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Load Cell 0-10V Transmitter

user4864313
Prodigy 100 points
Other Parts Discussed in Thread: OPA2277, XTR111, PGA300, OPA177, OPA277, DAC8871

Hi everyone, I want to design 0-10V transmitter for load cell but ı can't choice any op-amp. Please helping me for this. Thanks in advance

  • 0
    TI__Guru* 93105 points

    Hi user4864313,

    That really isn't enough information for us to be able to assist you. Does the transmitter drive the load cell, or does it drive a line following the load cell? Take a look at the questions above in the " When posting, please include the following:" section and provide as much information as you can.

    Regards, Thomas

    Precision Amplifiers Applications Engineering

  • 0 in reply to Thomas Kuehl
    Prodigy 100 points
    Hi Thomas, Thanks for reply. First, " When posting, please include the following:" section is ask to me which component use but my problem is already this and ı answer the another question.
    I will use this transmitter wtih load cell,rather ı will connect to load cell and this transmitter. It must be while there is no weight on my load cell output voltage is 0 V and while there is full weight on my load cell output voltage is 10V. Also this design must be working be a lineer.
    My load cells have a 3 type, 100 ohm,350 ohm and 700 ohm. I'm feeding this load cells 5V or 8V , it is not important to me. For example ı amsearching xtr11X series and maybe this series help me but ı can't be sure.
    All the details about design. If ı need to give any other information, ı am ready for this. Sorry for my English and again thank for your reply.
  • 0 in reply to user4864313
    TI__Guru* 93105 points

    Hello user4864313,

    I am not sure of your load cell configuration, but they are often a resistive bridge where one or more of the resistors in the bridge change value in response to the application of the external weight. Most often the bridge has a differential output voltage that is zero when no weight is applied, and it increases as the weight increases. The differential output voltage is ideally followed by a differential amplifier made up of a pair of op amps, or an integrated instrumentation amplifier. An example of a bridge amplifier is seen below that uses OPA2277 dual op amp. Some instrumentation amplifiers that may be used for this task are listed within the schematic.

    If you need a 4 to 20 mA current output the load cell amplifier can be followed by a Precision Voltage-to-Current Converter/Transmitter such as the XTR111. Additionally, there is the PGA300 which is a complete pressure sensor solution offering 4 to 20 mA output current capability. You can view the datasheet here:

    Regards, Thomas

    Precision Amplifiers Applications Engineering

  • 0 in reply to Thomas Kuehl
    Prodigy 100 points

    Thanks for reply, Thomas Kuehl. My Loadcell is some like your schematic and resistance is 100 ohm. I use OPA177 but when no weigh on load cell ı can't see 0 V to output. Maybe OPA2277 help to me. I will try and tell you.

  • 0 in reply to user4864313
    TI__Guru* 93105 points

    Hello user4864313,

    The input offset voltage of any op amp will be amplified by the gain used in the circuit. Since the offset voltage is seldom 0 V, but some real amount possibly as high as the maximum value, the output will not be 0 V with zero weight. The OPA2777 input offset voltage is rated to be a little lower than that of the OPA177, but you still will likely see a non-zero output with no load on the cell.

    Both the OPA177 and OPA277 single op amps have offset control pins which can be used to zero the output offset when the cell is unloaded. The feature is not available on the OPA2277 dual op amp. 

    Regards, Thomas

    Precision Amplifiers Applications Engineering

  • 0 in reply to Thomas Kuehl
    Prodigy 100 points

    Thanks for reply,

    I try to use OP177, but ı have not see 0 V output when ı use a trim trimpot. Also ı search internet and ı see trimpots break down during use. Now ı want to design a digital 0-10 V transmitter and when ı search an internet ı see ad5721 and ad5761 DAC but ı could not found  like this DAC in TI. Do you have a DAC that I can recommend

  • 0 in reply to user4864313
    TI__Guru* 93105 points

    user4864313,

    TI does not have exact replacements for the two DACs you mention, but there are others that TI offers that should work. 

    I am not involved with the DAC products, but looking over you requirements the DAC8871 may be provide good solution. It offers 16-bit resolution and an output voltage up to +/-18 V, which is set by the applied reference levels. It has an SPI interface. You can view the datasheet here:

    If you have questions about applying a DAC in this kind of application the Data Converter E2E forum may be able to best assist you.

    Regards, Thomas

    Precision Amplifiers Applications Engineering