Editing Transconductance (section)

=== Transconductance amplifiers ===
A '''transconductance amplifier''' (''g''{{sub|m}} amplifier) puts out a current proportional to its input voltage. In '''[[Network analysis (electrical circuits)|network analysis]]''', the transconductance amplifier is defined as a ''{{dfn|voltage controlled current source}}'' ({{abbr|VCCS}}). These amplifiers are commonly seen installed in a [[cascode]] configuration, which improves the frequency response.

An ideal transconductance amplifier in a voltage follower configuration behaves at the output like a resistor of value {{math|1/''g''{{sub|m}}}}, between a buffered copy of the input voltage and the output. If the follower is loaded by a single capacitor {{math|''C''}}, the voltage follower transfer function has a single pole with time constant {{math|''C''/''g''{{sub|m}}}},<ref>{{cite web | url=https://hasler.ece.gatech.edu/Courses/ECE6414/Unit3/gmCFilter01.pdf | title=Basics of Transconductance - Capacitance Filters | website=hasler.ece.gatech.edu | first=Paul | last=Hasler}}</ref> or equivalently it behaves as a 1st-order low-pass filter with a [[half-power bandwidth|{{val|-3|u=dB}} bandwidth]] of {{math|''g''{{sub|m}}/2''πC''}}.

==== Operational transconductance amplifiers ====
{{Main article|Operational transconductance amplifier}}
An [[operational transconductance amplifier]] (OTA) is an integrated circuit which can function as a transconductance amplifier. These normally have an input to allow the transconductance to be controlled.<ref name="MAX3724">{{cite web |title=3.2&nbsp;Gbps SFP Transimpedance Amplifiers with RSSI |url=https://datasheets.maximintegrated.com/en/ds/MAX3724-MAX3725.pdf |website=datasheets.maximintegrated.com |publisher=Maxim |access-date=15 November 2018}}</ref>