# Why does my comparator not give an output?

I am new to doing electronical things, so I bought some components and I am just trying thing out. Now, I am using a LM 2901-comparator, whichs documents you can find here.

Using a power supply of 3V, I measured the following pins,

Pin 3 (V+): 3.0V
Pin 4 (Input 1-): 1.5V
Pin 5 (Input 1+): 2.2V
Pin 12 (GND): 0.0V


according to the documents you would expect pin 2 to be 3.0 V since Vout = 1 if Vin+ => Vin-, but it is not giving an output at all.

Anyone that can explain why this is not working?

simulate this circuit – Schematic created using CircuitLab

• What do you mean it's "not giving an output at all"? What is happening? What are you measuring? Is it powered on? Are you sources connected correctly? – sherrellbc Jun 29 '14 at 20:23
• It is giving 0V. I am pretty sure the rest of the pins are wired up correctly. All other pins not mentioned are not connected to anything, could that be a problem? – Merijn Den Houting Jun 29 '14 at 20:25
• Take a 3K - 5K resistor and connect the output to Vcc – user34920 Jun 29 '14 at 20:26