Editing Differential amplifier (section)

{{Short description|Electrical circuit component which amplifies the difference of two analog signals}}
[[File:Op-amp symbol.svg|thumb|right|Operational amplifier symbol. The inverting and non-inverting inputs are distinguished by "−" and "+" placed in the amplifier triangle. V<sub>s+</sub> and V<sub>s−</sub> are the power-supply voltages; they are often omitted from the diagram for simplicity but must be present in the actual circuit.]]
{{also|Operational amplifier}}

A '''differential amplifier''' is a type of [[electronic amplifier]] that amplifies the difference between two input [[voltage]]s but suppresses any voltage common to the two inputs.<ref name="Laplante">{{cite book
 | last1  = Laplante
 | first1 = Philip A. 
 | title  = Comprehensive Dictionary of Electrical Engineering
 | edition = 2nd
 | publisher = CRC Press
 | date   = 2005
 | pages  = 190
 | url    = https://books.google.com/books?id=zoAqBgAAQBAJ&dq=%22differential+amplifier%22&pg=PA190
 | isbn   = 978-1420037807
 }}</ref> It is an [[analog circuit]] with two inputs <math>V_\text{in}^-</math> and <math>V_\text{in}^+</math> and one output <math>V_\text{out}</math>, in which the output is ideally [[Proportionality (mathematics)|proportional]] to the difference between the two voltages:
: <math>V_\text{out} = A(V_\text{in}^+ - V_\text{in}^-),</math> 
where <math>A</math> is the [[Gain (electronics)|gain]] of the amplifier.

Single amplifiers are usually implemented by either adding the appropriate feedback [[resistor]]s to a standard [[Operational amplifier|op-amp]], or with a dedicated [[integrated circuit]] containing internal feedback resistors. It is also a common sub-component of larger integrated circuits handling analog signals.