Operational transconductance amplifier
Operational transconductance amplifier
The operational transconductance amplifier (OTA) is an amplifier that outputs a current proportional to its input voltage. Thus, it is a voltage controlled current source. Three types of OTAs are single-input single-output, differential-input single-output, and differential-input differential-output (a.k.a. fully differential), however this article focuses on differential-input single-output. There may be an additional input for a current to control the amplifier's transconductance.
The first commercially available integrated circuit units were produced by RCA in 1969 (before being acquired by General Electric) in the form of the CA3080. Although most units are constructed with bipolar transistors, field effect transistor units are also produced.
Like a standard operational amplifier, the OTA also has a high impedance differential input stage and may be used with negative feedback. But the OTA differs in that:
The OTA outputs a current while a standard operational amplifier outputs a voltage.
The OTA is usually used "open-loop"; without negative feedback in linear applications.
The public source identifies “Operational transconductance amplifier” as operational transconductance amplifier. This brief keeps that definition visible, then builds a research path around Operational, transconductance and amplifier.
Why this record matters
A short description can identify a subject without explaining its stakes. For “Operational transconductance amplifier”, the useful work is to connect “operational transconductance amplifier” to the records capable of establishing context and consequence.
The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated Jul 29, 2026. The linked authority identifier is Q1239595. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1969.
A concise general-reference account can conceal disagreements about scope, terminology or the weight assigned to individual sources. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Operational transconductance amplifier”, its source revision and the description used here.
- Expand the search: follow Operational transconductance amplifier primary sources, Operational transconductance amplifier archive and Operational research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Operational transconductance amplifier”?
- What terminology or title could unlock a more precise catalogue search?
- Which institution is responsible for the underlying evidence?
Search terms from this dossier
This entry incorporates text from “Operational transconductance amplifier” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.