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 |
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 NERFINISHED ⓘ |
| 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 NERFINISHED ⓘ |
| 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 ⓘ |
Referenced by (3)
Full triples — surface form annotated when it differs from this entity's canonical label.