• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 50 subscribers
  • Views 270 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

INA185: Ina185

Charles Weaver
Prodigy 30 points
Part Number: INA185
Other Parts Discussed in Thread: INA196

Can this device be used in a 4-20ma current loop instrumentation measurement application?  Has anyone done this? If so can you share your experience and any info?

  • 0
    Guru 140200 points

    Hi Charles,

    can you tell more about your application?

    Kai

  • 0 in reply to kai klaas69
    Prodigy 30 points

    Yes basically to convert current from a 24 volt 4-20ma current loop sensor to a 0-5 volt signal (or other range) for input to an A/D converter.  I can do this with a discrete resistor as a shunt now but looking at other  alternatives.

  • 0 in reply to Charles Weaver
    TI__Mastermind 21730 points

    Hello Charles,

    Thanks for considering to use Texas Instruments.  You could measure 4 to 20 mA at the high-side with the INA185.  However, there will be some sort degree of error in the measurement.  The error can be attributed to gain error, linearity, offset, CMRR, and PSRR, and shunt tolerance (For more information, check out these tutorial videos).  For your conditions, if I use the RSS of all error terms with the 20V/V gain and 12ohm1% shunt, I would expect the error to be about 2% or better.  If you do an initial calibration with your system, you can remove the offset error and get even less error in your measurement.  If this error is too great, you might need to consider another device.  Typically error gets worse as you approach 0A.  This would be attributed to the device offset and input bias currents.

  • 0 in reply to Charles Weaver
    Guru 140200 points

    Hi Charles,

    the Arduino guys are using the INA196, if I rememeber correctly. But also with the INA196 Patrick's thoughts should be considered.

    Kai