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.

INA301 /ALERT pin for driving opto coupler

Other Parts Discussed in Thread: INA301

Hi Team,

We have an application question regards to INA301's /ALERT pin sink capability. Hope you can help to advice, thanks.

Can the ALERT pin can be used to drive an opto-coupler ?

What is the maximum current sinking capability of /ALERT pin ? Seem I could not find information from the datasheet, can you help to advice ?

Estimation from data sheet figure 33 reveal the output impedance is ~23ohm (100mV/4.3mA) when active, is it right ?

Let's say if the biasing of the opto is 10mA, and its voltage drop at 10mA is Vdrop, and using 5V pull up rail. Can I calculate the R-pullup using 5V - Vdrop - (23ohm*10mA) = R-pullup * 10mA ?

Look forward to your comments, thanks.

  • Hi Don,

    We will review your questions Monday and get back to you.

    Regards

  • Hi Don,

    The maximum sinking capability tested in our labs for the datasheet was 5mA, we can not guarantee that it will work for 10mA as your application need.

    You can definitely use Figure 33 to calculate output impedance, and your calculation seems correct.

    Your equation for R-pullup looks good, except that you should use the Maximum (worst case) Impedance of the Alert Pin (with 10mA) and we dont have that data, I would guess it should be something close to 100 ohms.

    I would not recommend to use this device for this application as you can run into liability problems. Again, I dont have data (at 10mA) to determine if it will work or not.