JPS6399485U - - Google Patents

Description

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration diagram showing an embodiment of the burst signal and chroma signal amplification circuit according to this invention;
FIG. 2 is a circuit diagram showing a conventional burst signal and chroma signal amplification circuit. 11...constant current source, 12...differential amplifier circuit, 13...
Signal source, 14...Power terminal, 15, 16...Terminal, 1
7... Control terminal, 18... Output terminal, 19, 20... Terminal, 21-23... Constant current source.

Claims (1)

[Claims for Utility Model Registration] First and second transistors whose emitter electrodes are commonly connected are provided, and a color television signal including a burst signal and a chroma signal is supplied to the base electrode of one of the transistors. a differential amplifier circuit, and a third transistor whose emitter electrodes are both connected to the collector electrode of one of the first and second transistors, and a first gain control voltage is supplied between each base electrode. a fourth transistor; and a fifth transistor, the collector electrode of which is connected to a reference potential point via a plurality of current limiting elements in series, and the emitter electrode of which is commonly connected to the emitter electrodes of the third and fourth transistors. Each emitter electrode is connected to the collector electrode of one of the transistors, and each collector electrode is connected to a different connection point between the plurality of current limiting elements, and each base electrode is connected to the collector electrode of one of the third and fourth transistors. sixth and seventh transistors to which a second gain control voltage is supplied; and the third and fourth transistors whose emitter electrodes are commonly connected to the first constant current source and whose base electrodes are connected to the third and fourth transistors. an eighth transistor whose collector electrodes are respectively connected to the base electrodes of the fourth and third transistors;
and a ninth transistor, each emitter electrode is commonly connected to the second constant current source, each base electrode is connected to the base electrode of the sixth and seventh transistor, and each collector electrode is connected to the second constant current source. the first transistor connected to the collector electrodes of the seventh and sixth transistors, respectively;
a twelfth transistor whose collector electrode is connected to the connection point between the plurality of current limiting elements and whose emitter electrode is connected to a third constant current source, and whose collector electrodes are common to each other; Each emitter electrode is connected to the reference potential point and is connected to a common connection point between the emitter electrodes of the eighth and ninth transistors and the first
A gate signal corresponding to a burst signal period is applied to the base electrodes of the 13th and 14th transistors connected to the common connection point of the emitter electrodes of the 0 and 11th transistors, respectively, and the 5th, 12th to 14th transistors. and during the burst signal period, the fifth
, the 12th to 14th transistors are turned on, and the third, fourth, sixth, seventh,
and a means for making the eighth to eleventh transistors conductive, and configured to obtain amplified outputs of the burst signal and the chroma signal from the collector electrode of the fifth transistor; Chroma signal amplification circuit.