• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 47 subscribers
  • Views 522 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.

INA217 phase shift

Norman Pellet
Prodigy 110 points

Other Parts Discussed in Thread: INA217

Hello !

I'm trying to use the INA217 or current sense amplification. I was happy to find this part because of it's high bandwidth at 40dB gain, which is what I am looking for.

However, I noticed that feeding 70kHz sine wave to the amplifier (5Ohm sense) already outputs a significant phase shift (a few percent). As it is meant for phase analysis of electrochemical systems, I cannot allow the amplifier to have such a phase shift. Weirdly, the same shift also appears for another INA on the board with 6dB gain only.

I checked the input of the INA (by referencing the other input to GND) and the signal is in phase with the input, and I checked at the output, and the signal is slightly out of phase with the input

Is this something I should have expected from this part ?

  • 0
    TI__Mastermind 25875 points

    Hello Norman,

    I expect some phase shift and it should depend on the frequency of the input signal. Unfortunately there is no SPICE model (or information in the datasheet) for the INA217 to help us predict the phase shift due to the device.

    Therefore I recommend a couple things. First, please verify that there is a relationship between the input frequency and the phase shift. Second, try to ensure that there is minimal parasitic capacitance on the input pins and that the impedance of the inputs are as matched as possible. I'd be happy to take a look at your PCB layout and schematic if available.