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INA199: Asking for the current sense design on INA199

SHH
Mastermind 31446 points
Part Number: INA199

Hi Team,

Customer is designing the current sense solution INA199

Here are the requirement.

  1. Monitoring voltage range is 4.5V~5V
  2. Monitoring current is less than 200mA.
  3. Current shunt resistor is not decided

Would you please provide suggestions on this design and what need to take care at the beginning design?

 

BR,

SHH

  • 0
    TI__Mastermind 32395 points

    Hello SHH,

    My suggestions are to determine as many of the following requirements below:

    1. Is this a bidirectional current application?
    2. Are there any bandwidth or step response requirements or is this purely a DC current application?
    3. What is the smallest current level customer wants to sense and with what allowable error budget?
    4. What is the maximum shunt resistor power dissipation or voltage drop allowable?
    5. What is the maximum current level engineer wants to sense and with what allowable error budget?
    6. What is the INA199 going to drive? What’s the signal chain after INA199? So what is the desired full-scale output voltage range given the input sense current range?
    7. What is the temperature range of this application?

    These questions help determine the shunt resistor value and device gain. Error will always dominate at the lower current level measurement so you want the shunt resistor to be large enough so that the shunt voltage is sufficiently large compared to the device’s input offset. However, the shunt resistor cannot be too big or else there will be increased power dissipation.

    Hope this helps.

    Best,

    Peter