trying to understand a comparator

from what i remember in school, a comparator basically has 2 inputs, 1 which is the reference voltage, and the other comes from somewhere else and whichever is higher, is the voltage used for the next part in the circuit. is it that easy though? where would a comparator be used? i guess i'm wondering if i've ever dealt with a comparator and not realized it.

Yes, simply if the voltage on the + input is higher than the - input the output is HI, otherwise it is LO. ONe does not have to be a fixed reference- both voltages can be changing or whatever.

THey are 1-bit ADCs and they are used to build every type of ADC. Sometimes just one or sometimes a bunch. Like a flash ADC is really just a bunch of comparators each with a different voltage reference to account for each "step" in voltage.

Comparators are also used to detect when an analog voltage crosses zero like in an AC line when things might need to happen like switching. THey are also used to detect overvoltage or overcurrent for motor electronics.

They're used everywhere.

Snaz said:

from what i remember in school, a comparator basically has 2 inputs, 1 which is the reference voltage, and the other comes from somewhere else and whichever is higher, is the voltage used for the next part in the circuit. is it that easy though? where would a comparator be used? i guess i'm wondering if i've ever dealt with a comparator and not realized it.

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thats a very good concept of a one bit adc dk..

Hi Snaz,Welcome to the forum.Comparators can be defined as devices that change their o/p according to the voltage difference b/w their i/ps as said by dknu..

there is a very good info(theoritical) about comparators and here is one of the application notes of maxim which were pointed out by Eric.It shows how to design a comparator.

**broken link removed**

Snaz said:

from what i remember in school, a comparator basically has 2 inputs, 1 which is the reference voltage, and the other comes from somewhere else and whichever is higher, is the voltage used for the next part in the circuit. is it that easy though? where would a comparator be used? i guess i'm wondering if i've ever dealt with a comparator and not realized it.

Click to expand...

Have you Googled "comparator"? The first page of the search results has several good sites with basic information.