Constant-current generator, differential amplifier, and semiconductor integrated circuit
US6452453B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 1, 2000 |
| Grant date | Sep 17, 2002 |
| Priority date | — |
| Expiry date | May 1, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45508
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The constant-current generator comprises a bias transistor whose drain and gate are connected to each other, and an outputting transistor. The threshold voltage of the outputting transistor is smaller than that of the bias transistor. The outputting transistor has the same source voltage and the same gate voltage as those of the bias transistor. Therefore, the gate-to-source voltages of the outputting transistor and the bias transistor are always kept equal. On the other hand, the drain-to-source current of the outputting transistor becomes larger than that of the bias transistor in accordance with the difference between the threshold voltages of the outputting transistor and the bias transistor. Accordingly, the outputting transistor can output a stable drain-to-source current even when the drain voltage of the bias transistor has shifted to lower the gate-to-source voltage thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.