Comparator with 150 mv reference?

Thread Starter

MBG

Joined Jan 30, 2022
23
I have no experience with a voltage this low so need to ask. Is there a comparator (single +5v supply) where I can set the reference voltage to 150 - 200mv ? I need to try and get a logic hi/lo when a voltage drops below this range. -- Thanks
Do have some LM311 on the way but not sure if I can use them for this.
 

ericgibbs

Joined Jan 29, 2010
15,713
hi MBG,
This is a Draft simulation of a LM311 with your parameters.

E


Updated image for LOW when less than 0.2V

EG 1383.gif
 
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crutschow

Joined Mar 14, 2008
30,113
You can use a voltage reference IC, such as the 2.5V, TL431, and use a resistor divider to reduce that to 200mV, for example, 1kΩ to ground in series with 11.5kΩ to the 2.5v. The junction of the two resistors will be at 200mV.

Edit: Below is Eric's basic circuit with the added reference voltage.

1644101396145.png
 
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