Explore LM393 pins, signal names, electrical functions and connection guidance for each package.
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Channel A sinks current when IN1− is above IN1+.
Add a 10 kΩ pull-up to +5 V; read this node with a high-impedance input.
The IC does not actively drive HIGH.
Channel A reference input in the illustrated circuit.
Connect the 2.00 V divider node.
Keep both example inputs within 0–3 V at a 5 V supply.
Channel A measured signal.
Connect VIN and a common ground.
Ground reference for both comparators.
Connect the supply return and bypass capacitor.
Channel B positive input.
Tie to GND when unused in this example.
Channel B negative input.
Connect to the same 2 V reference to give the unused channel a defined state.
Channel B current-sinking output.
Leave unconnected in the single-channel example.
Use a separate pull-up when using channel B.
Shared positive supply for both comparators.
Apply +5 V; place 100 nF between pins 8 and 4.
Classic LM393 recommended supply: 2–30 V.
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