Attenuator control circuit
US6600372B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 3, 2001 |
| Grant date | Jul 29, 2003 |
| Priority date | — |
| Expiry date | Dec 3, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45701
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An attenuator control circuit for controlling operation of a differential pair attenuator to provide linear in decibels (dB) operation and temperature and process-independent operation. The attenuator control circuit is coupled in parallel with corresponding control input terminals of the attenuator differential pair. The attenuator control circuit also includes a current control circuit that sources a supply current to the control differential pair. The attenuator control circuit also includes an amplifier that controls current through the first current path of the control differential pair to maintain constant total current, so that the first current path exhibits the desired exponential attenuation function. Since the control differential pair is coupled in parallel with the differential pair attenuator, the output current of the differential pair attenuator also exhibits the desired exponential attenuation function. Furthermore, the attenuator control circuit includes a temperature compensation circuit that applies a temperature proportional voltage to compensate for temperature variations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.