Title:
AMPLIFIER
Document Type and Number:
Japanese Patent JP3039613
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To obtain amplifier capable of preventing the instantaneous disconnection of a signal in case of switching gain and having high application efficiency of power supply voltage and a large gain variable range.
SOLUTION: In the amplifier, each of variable gain units 311 to 31n including variable gain amplifier circuits generates one of gain control outputs Sc1 to Scn from one of input signals Si1 to Sin, based on one of control power supply voltage Vc1 to Vcn and one of gain control signals Cg1 to Cgn. In case of inputting a control signal C and outputting each of gain control signals Cg1 to Cgn, a gain controller 11 controls at least two of respective variable gain units 311 to 31n mutually in reverse directions. In case of generating each of the control power supply voltage Vc1 to Vcn based upon one of the gain control signals Cg1 to Cgn and power supply voltage Vcc, each of power supply controllers 211 to 21n interrupts the impression of corresponding control power supply voltage out of the voltage Vc1 to Vcn to a corresponding variable gain amplifier circuit when the gain of the corresponding gain control signal out of the signals Cg1 to Cgn is minimized.
Inventors:
Souichi Tsumura
Application Number:
JP21923295A
Publication Date:
May 08, 2000
Filing Date:
August 28, 1995
Export Citation:
Assignee:
NEC
International Classes:
H03F1/02; H03F3/68; H03G3/00; H03G3/20; (IPC1-7): H03G3/20; H03F1/02; H03F3/68
Domestic Patent References:
| JP5883437A | ||||
| JP60212013A |
Attorney, Agent or Firm:
Naoki Kyomoto (2 outside)
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