Circuits and methods for providing a current reference with a controlled temperature coefficient using a series composite resistor
US6351111B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 13, 2001 |
| Grant date | Feb 26, 2002 |
| Priority date | — |
| Expiry date | Apr 13, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S323/907
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A current reference circuit provides a reference current that has a controlled temperature coefficient and is relatively stable with supply voltage fluctuations. The reference leg includes a series of MOS transistors including at least one PMOS transistor that is electrically closer in the series to a high voltage source, at least one NMOS transistor that is electrically closer in the series to the low voltage source. The series composite resistor comprises at least two resistors coupled in series within the current path. The size of the resistors may be designed so as to lower the temperature dependency of the circuit. A bipolar transistor is also coupled in the reference leg. The mirror leg is similar to the reference leg except that no series resistor is provided, and the emitter area of the bipolar resistor in the reference leg is larger than the emitter area of the bipolar transistor in the mirror leg.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.