Reference buffer with multiple gain stages for large, controlled effective transconductance
US5854574A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 26, 1996 |
| Grant date | Dec 29, 1998 |
| Priority date | — |
| Expiry date | Apr 26, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45658
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A reference buffer suitable for driving switched-capacitor or resistive load circuits provides a very low output impedance. The reference buffer utilizes an amplifier with a very large and controlled transconductance configured in feedback and compensated by a load capacitance. Cascaded gain stages are used to provide a large, controlled transconductance. In one embodiment, a reference buffer amplifier includes a plurality of voltage gain amplifiers connected in cascade and at least one transconductance amplifier connected to a last-connected of the plurality of voltage gain amplifiers. The amplifier may further include at least one current mirror amplifier connected to the at least one transconductance amplifier. In another embodiment, the reference buffer amplifier includes at least one transconductance amplifier and at least one current mirror amplifier cascade-connected to the at least one transconductance amplifier. The amplifiers can be differential or single-ended.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.