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.

INA169: Asking for current sensing INA169 solution

Part Number: INA169

Hi Team,
cusotmer would like to seek the similiar function as INA169 with EVM. (sense current and transfer to voltage). could you please recommend the proper or new on for this application?


Another question for INA169 max output voltage.
If cusotmer would like to monitor 12V/5A(max), the pin5 Vdd is 5V, the Vout max is limit to 5-0.7-(Vin+-Vin-).
If the Vout reach the limit, the Vout will keep at the Vout max level and won't trigger any protection by IN169 itself, right?

BR,
SHH

  • Hello SHH,

    Thanks for reaching out on the forum.  As for an EVM, we actually do not have one available.  However, we do have a TI design with altium files that your customer may be able to leverage.  Those files can be found here.  Yes the Vout should be limited according to the formula you have above.  Other than ESD cells,there are no internal protective mechanisms that will trigger from operating conditions outside of the intended operating range.

  • Hi Patrick,
    Do we have similar solution to this device with EVM?


    BR,
    SHH
  • Hello SHH,

    Currently we do not.
  • Hi Patrick,
    Customer has the following questions.
    Customer would like to to monitor PVDD 20V 5Acurrent.
    V+ :5V.
    rs= 10mohm
    Vin+=20V
    Vin-=20V-0.01*5= 19.95V.

    What is the Voutmax?

    if we follow equation 1 on d/s page 9, the Voutmax is 5-0.7-(20-19.95)=4.25V.
    if we follow equation 2 on d/s page 9, the Voutmax is 19.95-0.5=19.45V.

    Which one is correct? customer expect the Vo is under 5V due to ADC limitation.

    for the figure 9 Voltage Gain, could you please give me more expression on the voltage gain?







    BR,
    SHH
  • Hello SHH,

    According to the datasheet (posted below), the voutmax for your customer's condition should be 4.25V.

    Based off of equation 3 (posted below), this is a transconductance amplifer, which means the output current is proportional to the vsense voltage across the input pins.

  • Hi Patrick,
    Yes.
    Customer has the following two questions.
    1. Can INA169 work without V+? or V+ is must if need this INA169 to be functional.
    2. Customer is curious what the situation to use equation 2. Because equation 1 always get the lower value, then why and when need the equation 2?


    BR,
    SHH
  • Hello SHH,

    1. The customer needs V+.

    2. We can derive the situation as such:
    (V+)-0.7V-((Vin+)-(Vin-))<(Vin-)-0.5V
    (V+)-0.2-IsRs<(Vin+)-IsRs
    (V+)-0.2>(Vin+)

    With this lets assume Vsense was designed for a max drop of 1V, had a common mode of 2.7V, and a supply of 5V. Equation one would yield 4.3V as the max output while equation 2 would yield 1.2V for the max output.