2.8v supervisor

Quick question for anyone with supervisor knowledge…?? I am looking at MCP100T-300I/TT as a supervisor to cut off at around 2.9v. I just want to make sure that there is no current limitation (within reason, of course) before I try to apply this to my project. I operate around 80-150mah. I have looked at the data sheet and don’t see any current limitation. Just looking for clarification.

Hello sllsrbrt, Welcome to the DigiKey TechForum.
I checked the datasheet, and I did not see a current limit for this part either.
Maybe one of the Engineers can add to this post, if they have experience using this part.

Thanks for the warm welcome! I appreciate the response. I do see the operating current in the uF range, but that says to me device operating, not in/out current… thoughts?

Check out Figure 2-6 VOL vs IOL

I believe this would advise to the output current as you’re chosen the Active Low component.

If you were using the Active High version I believe the below graph would apply.

Also figure 2-8: VDD - VOH vs. IOH



Thanks for the info. Any thoughts on a supervisor that could supply enough current.?

Supervisors are sensors that generate control signals to which other equipment responds, in the same sense that a thermostat controls the temperature in one’s home, but does not by itself produce a heating/cooling effect.

The current carrying capacity of your system will be determined by whatever power switching device you choose to control with your supervisory device.

Copy that. I’ll look into a spst NO relay. Thank you.

Having done a fair amount of searching for supervisors to serve as Low Battery Indicators that source(sink) current for an LED, you’re lucky if you find one that can handle 20mA. Most are around 10mA.

If you need more than that you can use the supervisor to trigger a transistor/MOSFET.

Instead of a transistor… would something like this work. Seems to fit the project…


Hello sllsrbrt,

It sounds like you have a low power circuit. I suspect this has a nominal 3.3 with a few mA load.

I suspect a relay will quickly overrun your energy budget.

While I don’t have an immediate answer to your needs, I would like to point you to this older EEV Blog video. Here Dave presents a MOSFET solution that provides a relative low-cost solution. Perhaps you could adopt the circuit to your needs. If your circuit has a microcontroller, you may be able to initiate a controller turn off. Perhaps the MCP100T-300I/TT supervisor circuit you mentioned would still be useful as an input to the microcontroller.

Best Wishes,


P.S. In your original note, was that mA or mAh?

Hi sllsrbrt,

The TLP240A(D4,LF1,F, along with the appropriate current limiting resistor, would function as a power switch to be controlled by the MCP100T-300I/TT. However, it requires an absolute minimum of 5mA on the input LED to guarantee proper turn-on. The MCP100T-300I/TT can probably handle that, but it is pushing its limits.

Something like the CPC1018N is a better choice because it is guaranteed to turn on with only 1mA. It can handle a load current of up to 600mA, so plenty of headroom for you.