LM2904: OPAMP vs COMPARATOR

David Kim2

Genius 3635 points

Part Number: LM2904
Other Parts Discussed in Thread: LM2903

I want to know the difference between OPAMP and Comparator.

LM2904 is OPAMP. Is there a problem using both comparator and OPAMP with LM2904?

And is there a difference between using(OPAMP, comparator) both LM2904 and LM2903 as comparator and LM2904 as OPAMP?

Thanks

over 5 years ago

0 Ron Michallick over 5 years ago

TI__Guru**** 170936 points

David,

LM2904 can be used as a comparator. The propagation time, rise time, and fall time will be longer than using LM2903.

See Design Guidelines for Devices with LM324/LM358 Cores for more details

0 Paul Grohe over 5 years ago

TI__Guru 66696 points

Hello David,

Also see this post:

https://e2e.ti.com/support/amplifiers/f/14/t/513557

And Bruce Trumps Blog:

e2e.ti.com/.../op-amps-used-as-comparators-is-it-okay

In short...it's better to use a "real" comparator, but it's OK if you "borrow" an extra channel of an op-amp - as long as the op-amp input allows for large differential inputs.

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LM2904: OPAMP vs COMPARATOR