Editing Comparator (section)

=== Open collector output ===
{{Main article|Open collector}}
Some comparators (e.g. LM339) use [[open collector]] output to help interface to different logic families. When the inverting input is at a higher voltage than the non inverting input, the output of the comparator connects to the negative power supply. When the non inverting input is higher than the inverting input, the output is [[high impedance]], so the output voltage in this state can be set by an external [[pull-up resistor]] to a different voltage supply.