JPH03278708A - Gain variable type amplifier circuit - Google Patents
Gain variable type amplifier circuitInfo
- Publication number
- JPH03278708A JPH03278708A JP7961490A JP7961490A JPH03278708A JP H03278708 A JPH03278708 A JP H03278708A JP 7961490 A JP7961490 A JP 7961490A JP 7961490 A JP7961490 A JP 7961490A JP H03278708 A JPH03278708 A JP H03278708A
- Authority
- JP
- Japan
- Prior art keywords
- amplifier circuit
- resistor
- circuit
- resistors
- collector
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000004020 conductor Substances 0.000 abstract 3
- 239000003990 capacitor Substances 0.000 abstract 2
- 230000001808 coupling Effects 0.000 abstract 1
- 238000010168 coupling process Methods 0.000 abstract 1
- 238000005859 coupling reaction Methods 0.000 abstract 1
Abstract
PURPOSE: To reduce number of circuit components by providing a control terminal receiving an input signal, a transistor(TR) having 1st and 2nd conductor terminals and a control element varying a current flowing between the 2nd conductor terminal and a 2nd voltage source and extracting an output signal from the 1st conductor terminal.
CONSTITUTION: An amplifier circuit 1 is provided with an NPN TR Q1 whose emitter connects to ground via a resistor R1, a resistor R3 provided between a collector of the TR Q1 and a power supply Vcc, series connection of resistors R1, R2 provided between the power supply Vcc and ground to provide a bias voltage to a base of the TR Q1 and a coupling capacitor C1. The connecting point between the resistors R1 and R2 connects to a base of the TR Q1 and the capacitor C1. An output signal of the amplifier circuit 1 is extracted from the collector of the TR Q1. Thus, the circuit is formed by having only to connect one TR to a common emitter amplifier circuit via a resistor and the number of circuit components is reduced.
COPYRIGHT: (C)1991,JPO&Japio
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2079614A JP2691632B2 (en) | 1990-03-28 | 1990-03-28 | Variable gain type amplifier circuit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2079614A JP2691632B2 (en) | 1990-03-28 | 1990-03-28 | Variable gain type amplifier circuit |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH03278708A true JPH03278708A (en) | 1991-12-10 |
JP2691632B2 JP2691632B2 (en) | 1997-12-17 |
Family
ID=13694928
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2079614A Expired - Lifetime JP2691632B2 (en) | 1990-03-28 | 1990-03-28 | Variable gain type amplifier circuit |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP2691632B2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2008126282A1 (en) * | 2007-03-30 | 2008-10-23 | Fujitsu Limited | Amplifier circuit |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS4721542U (en) * | 1971-03-19 | 1972-11-10 | ||
JPS52148029U (en) * | 1976-05-06 | 1977-11-09 | ||
JPS61230506A (en) * | 1985-04-05 | 1986-10-14 | Fujitsu Ltd | Variable gain amplifier circuit |
-
1990
- 1990-03-28 JP JP2079614A patent/JP2691632B2/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS4721542U (en) * | 1971-03-19 | 1972-11-10 | ||
JPS52148029U (en) * | 1976-05-06 | 1977-11-09 | ||
JPS61230506A (en) * | 1985-04-05 | 1986-10-14 | Fujitsu Ltd | Variable gain amplifier circuit |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2008126282A1 (en) * | 2007-03-30 | 2008-10-23 | Fujitsu Limited | Amplifier circuit |
US8283980B2 (en) | 2007-03-30 | 2012-10-09 | Fujitsu Limited | Amplifier circuit |
Also Published As
Publication number | Publication date |
---|---|
JP2691632B2 (en) | 1997-12-17 |
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