Constant temperature coefficient self-regulating CMOS current source
US6831504B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 2003 |
| Grant date | Dec 14, 2004 |
| Priority date | — |
| Expiry date | Mar 27, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/245
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A current source includes a first circuit branch of a pair of diode-connected transistors with a resistor connected at the drain terminal and a second circuit branch of an inverter pair of transistors. Both of the circuit branches are supplied by a first current source powered by a supply voltage. The transistors are biased in the subthreshold region and have non-nominal size ratios. A first voltage and a second voltage are established across the resistor and the voltage difference causes a current proportional to absolute temperature to flow in the resistor. The second circuit branch functions as an error amplifier providing an “error signal” to facilitate voltage regulation. The regulation is realized in a third circuit branch which receives the “error signal” and draws excess current from the first current source so that the first voltage and the second voltage remain at the ideal regulated operation point.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.