what is the difference between opamp & differential amplifier?

 

They are very similar, differential amplifier is a subset of op amps.

Basically a differential amplifier has two outputs, whose difference is the gain of the + and - inputs.

 

It's more in the application than the device itself. Most op-amps can be used as differential amps, but often aren't.

eric

 

http://en.wikipedia.org/wiki/Differential_amplifier

Differential amplification is one of the many applications of OpAmps like KL7AJ just pointed out. The use of OpAmps used in this way might be to reduce the noise in your application. You know, the input takes the difference between two signals and "rejects" the common mode gain which could be noise due to various sources.

Hope that helps.

 

A differential amplifier may have only one output, wherein the output is the amplified difference between the two inputs. A fully differential amplifier has two outputs.

 

Differential amplifier is referred as two input whereby the difference in input is amplified as opposed to a single ended amplifier where one input is signal the other is common. Differential amplifier can and will amplify the difference between two high common mode signal.

 

an op-amp can be configured as a diff-amp, however, today we have already diff-amp devices on the market, so no need to reconfigure your simple op-amps to be diff-amps.