Variable gain amplifier having a maximum attenuation-factor limiting resistor
US6198349A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 5, 1999 |
| Grant date | Mar 6, 2001 |
| Priority date | — |
| Expiry date | Mar 5, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G3/001
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A variable gain amplifier has a large variable range of a gain with respect to an analog signal having a level changing at a high-speed. The variable gain amplifier is provided with a digital-setting-type signal attenuator having a resistor string including a plurality of resistors connected in series. A maximum attenuation-factor limiting resistor is connected between the resistor string and a ground. Each of the analog switches is connected to respective points of the resistor string. A decoder generates a control signal for selecting at least one of the analog switches, the control signal being generated based on setting data provided from an external device. A voltage across the resistor string is divided by the resistors included in the resistor string, and the divided voltage is output to an amplifier from at least one of the analog switches selected by the control signal generated by the decoder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.