Constant current circuit operating independent of temperature
US7411442B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 18, 2006 |
| Grant date | Aug 12, 2008 |
| Priority date | — |
| Expiry date | Sep 30, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/262
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
In CMOS processing, there may be a case in which a resistance element, such as a poly-silicon resistance, or the like, may be formed which has negative temperature characteristics. In a constant current circuit using this resistance element, a constant current output less affected by the influence of varying temperature is obtained. To a load-side path of a current mirror circuit, a serial connection circuit and a temperature compensation circuit are arranged in parallel each other. The serial connection circuit includes a transistor Q1, a resistance element R1 and a bipolar transistor Q6 and flows a current I1 having positive temperature characteristics. The temperature compensation circuit includes a transistor Q8 and a resistance element R2 and flows a current I2 having negative temperature characteristics. A constant current output based on the sum current I of the currents I1 and I2 is obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.