Dynamic transconductance boosting technique for current mirrors
US7119605B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 23, 2004 |
| Grant date | Oct 10, 2006 |
| Priority date | — |
| Expiry date | Jan 28, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/262
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
Circuits and methods to increase the transconductance of a current mirror in case of small input currents of the current mirror without affecting the transconductance of said current mirror in case of large input currents have been achieved. Key of the invention is a “bypass” formed by a transistor in series with a resistor, wherein the bypass is in parallel to the input transistor of the current mirror. This bypass is only relevant for very small input currents wherein the resistor can be neglected compared to the impedance of the bypass-transistor and therefore the total transconductance of the current mirror is increased in case of very small input currents. For large input currents the resistor of the bypass effectively blocks the “bypass” path. The invention solves e.g. a problem of amplifiers having any kind of dynamic biasing namely that the input impedance of current mirrors becomes too large for very small input currents.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.