Equivalent variable resistor circuits
US5838184A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 21, 1997 |
| Grant date | Nov 17, 1998 |
| Priority date | — |
| Expiry date | May 21, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H11/24
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An equivalent variable resistor circuit for use in an integrated circuit includes a signal path extending from a signal input terminal through a first resistor to a signal output terminal, a first transistor having its collector connected with a signal output portion of the signal path between the first resistor and the signal output terminal, a second transistor having its collector connected with a DC voltage source and its emitter connected with an emitter of the first transistor for forming a differential pair with the first transistor, a third transistor having its collector connected with the emitters of the first and second transistors connected with each other and its emitter connected through a second resistor to a reference potential point to form a voltage to current converting portion with the second resistor, and a voltage controlling portion provided for varying a DC voltage supplied between bases of the first and second transistors, so as to vary equivalently a resistance of the signal path between the signal input terminal and the signal output terminal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.