Patent · US Expired

Integrated circuit having a variable-gain amplifier

US5323123A · kind A · utility

11Cited by
1References
5Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 21, 1992
Grant dateJun 21, 1994
Priority date
Expiry dateDec 21, 2012

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03D7/125
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

An integrated circuit includes a variable-gain amplifier having a first transistor with a load arranged as an inverted and controlled by a first signal of a first frequency, and also having a branch comprising a capacitance in series with a transistor which is arranged as a variable resistance and whose impedance is modulated by a second signal of a second frequency. In this circuit the variable-gain amplifier comprises a second transistor with a load arranged as an inverter and disposed in series with the first transistor and its load between this load and a d.c. supply, in such a manner that the two inverter transistors share the same current, the second inverter being controlled by the output of the first inverter, and the impedance modulated by the second signal is coupled to a node between the load of the first inverter transistor and the second inverter transistor in order to modulate the gain of the latter.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.