Widlar current source

E1026750

The Widlar current source is an analog integrated circuit design that produces a precise, low-magnitude reference current using a resistor and transistor pair with emitter degeneration, widely used in early linear ICs.

All labels observed (1)

Label Occurrences
Widlar current source canonical 3

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Statements (41)

Predicate Object
instanceOf analog integrated circuit building block ⓘ
current source circuit ⓘ
achieves small reference currents with moderate resistor values ⓘ
category analog circuit design ⓘ
reference current generator ⓘ
comparedTo simple current mirror ⓘ
designedFor monolithic integrated circuits ⓘ
developedBy Bob Widlar ⓘ
developedFor early monolithic linear ICs ⓘ
enables on-chip biasing currents of a few microamperes ⓘ
field analog electronics ⓘ
integrated circuit design ⓘ
hasAdvantage better control of small bias currents ⓘ
smaller chip area than using very large resistors for low currents ⓘ
hasLimitation limited output voltage compliance compared to ideal source ⓘ
sensitivity to transistor parameter variations ⓘ
hasProperty improved matching over simple current mirror at low currents ⓘ
integrated-circuit-friendly implementation ⓘ
low-magnitude reference current ⓘ
reduced output current without large resistors ⓘ
temperature-compensated current ⓘ
hasTopology two-transistor current mirror with emitter resistor in one leg ⓘ
historicalUse widely used in early linear IC families such as μA709 and μA741 era designs ⓘ
improvesOn simple current mirror at low currents ⓘ
isPartOf classic analog IC design techniques ⓘ
namedAfter Bob Widlar ⓘ
operatesWith bipolar technology ⓘ
relatedTo Wilson current mirror ⓘ
bandgap reference ⓘ
beta-helper current mirror ⓘ
reliesOn base-emitter voltage difference between transistors ⓘ
exponential I–V characteristic of BJTs ⓘ
tradeOff increased design complexity for better low-current performance ⓘ
usedIn analog reference circuits ⓘ
linear integrated circuits ⓘ
operational amplifiers ⓘ
voltage regulators ⓘ
usesComponent bipolar junction transistor ⓘ
resistor ⓘ
usesEffect logarithmic relationship between current ratio and Vbe difference ⓘ
usesTechnique emitter degeneration ⓘ

How these facts were elicited

Referenced by (3)

Full triples — surface form annotated when it differs from this entity's canonical label.

Bob Widlar → knownFor → Widlar current source ⓘ
Bob Widlar → invented → Widlar current source ⓘ
Bob Widlar → hasConceptNamedAfter → Widlar current source ⓘ