JPS62133486U

JPS62133486U -

Info

Publication number: JPS62133486U
Application number: JP1888986U
Authority: JP
Priority date: 1986-02-14
Filing date: 1986-02-14
Publication date: 1987-08-22

Description

[Brief explanation of drawings]

第１図は本考案の帯域増幅回路の一実施例を示
す回路図、第２図は第１図の回路における入力振
幅（ＰＩＦ出力）に対する出力振幅（色信号出力
）の特性を示す図、第３図は従来の帯域増幅回路
を示す回路図、第４図は第３図の回路における入
力振幅に対する出力振幅の特性を示す図である。１１……ＩＣ、１２……入力端子、１３……３
．５８ＭＨｚテイクオフ回路、１４……出力端子
、１５……スイツチ、Ｑ１〜Ｑ１０……トランジ
スタ、Ｒ１〜Ｒ８……抵抗、Ｉ……定電流源、Ｃ
１，Ｃ２……コンデンサ。 FIG. 1 is a circuit diagram showing an embodiment of the band amplification circuit of the present invention, FIG. 2 is a diagram showing the characteristics of the output amplitude (color signal output) with respect to the input amplitude (PIF output) in the circuit of FIG. FIG. 3 is a circuit diagram showing a conventional band amplification circuit, and FIG. 4 is a diagram showing the characteristics of output amplitude with respect to input amplitude in the circuit of FIG. 11...IC, 12...input terminal, 13...3
．． 58MHz take-off circuit, 14...Output terminal, 15...Switch, Q1-Q10...Transistor, R1-R8...Resistor, I...Constant current source, C
1, C2... Capacitor.

Claims

[Claims for Utility Model Registration] An input terminal into which a video intermediate frequency signal is input; a switch connected to this input terminal via a resistor for switching between two types of DC voltage and applying the same to the input terminal; Connected to the input terminal via a capacitor,
a bandpass circuit for extracting a color signal from the video intermediate frequency signal; and a bandpass circuit for inputting the color signal from the bandpass circuit to the base of a first transistor of the first and second transistors forming a differential pair. , its collector is connected to a voltage source to give a bias voltage to the bases of both transistors, and a constant current source is connected to the common emitter.
A differential amplification means for performing an amplification operation; a collector of a third transistor of the third and fourth transistors forming the differential pair is connected to a voltage source via a first load resistor; a first differential amplifier, the collector of which is connected to a voltage source and whose common emitter is connected to the collector of the second transistor of the differential amplification means via a collector-emitter path of a fifth transistor; The collector of the sixth transistor of the pair of sixth and seventh transistors is connected to the voltage source via the second load resistor, the collector of the seventh transistor is connected to the voltage source, and the common emitter of the eighth transistor is connected to the voltage source. a second differential amplifier connected to the collector of the second transistor of the differential amplification means via the collector-emitter path of the transistor, and the bases of the third and sixth transistors are common. The bases of the fourth and seventh transistors are connected in common, and an AC voltage is connected between the bases of the third and fourth transistors.
C control voltage is applied to the base of the fifth transistor, a DC voltage from the input terminal is applied to the base of the fifth transistor, and a bias voltage is applied to the base of the eighth transistor. A band amplifier circuit comprising: a circuit for operating one of the first and second differential amplifiers and extracting color signal outputs having different gains from the collectors of the third and sixth transistors. .