• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 31 subscribers
  • Views 395 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

Constant current source with INA 219

Juan Gomez6
Prodigy 10 points
Part Number: INA219


Hey there

I'm using iNA 219 to measure the current trough a led series, im using it to detect fails. I'm using a constant current source to drive these less but I hace a question. The ina 219 datasheet explain that the Voltage between V+ and V-  must to be <26V (V+ - V- < 26V). If I understand as well, I could use a constant current source who impose 100Vdc in V+ and the shunt voltage must be > 74Vdc and everything will be ok?. I have to know how many leds I could use in series with INA 219. The other option would be use the shunt resistor between the last led and ground.

Thanks 

\

  • 0
    TI__Mastermind 35030 points

    Hi Juan,

    You’re correct that the voltage between input pins must be <26V. Related however, is the common mode voltage requirement:

    Based on this requirement, each of the input pins must not exceed 26V relative to ground. Therefore both 100V and 74V are too high and will damage the device. The option of using “the shunt resistor between the last led and ground” is OK though.

    Regards, Guang