Ladder tracking buffer amplifier
US5973540A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 23, 1998 |
| Grant date | Oct 26, 1999 |
| Priority date | — |
| Expiry date | Jan 23, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F1/301
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A structure and a method are provided to receive a high-impedance reference voltage signal and generate a desired output signal that is capable of sourcing enough current to meet the demands of a fixed-resistance load. In such a circuit, the signal from an accurate, wide output-swing voltage source circuit having low quiescent current is combined with the output of a current source circuit so that the voltage input to the load is maintained even as the necessary current is supplied. The current source circuit preferably includes a tracking resistance that sinks a control current which a current mirror multiplies by the same ratio as that between the tracking resistance and the load resistance. In addition, it is preferable for the tracking resistance to be large compared to the load resistance, in order to minimize quiescent current draw, and also for the tracking resistors to be created and located at the same time and place as the load resistance, to minimize the effects of sheet resistance variations and temperature changes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.