| 摘要 |
PURPOSE:To reduce a signal current which flows to a power line and to reduce a decrease in high-band amplification factor by using a common collector circuit as an input stage and a common base circuit as an output stage, and cascading them. CONSTITUTION:The current of an emitter resistance 18 varies with a video input signal supplied to the base of a transistor (TR)17. The base voltage of a TR19 is fixed, so the current of a resistance 20 is constant, and the current variation of the resistance 18 is variation in the emitter current 19 as it is and then variation in the collector current, which is supplied to a collector resistance 11 and a load connected to an output terminal 14. Thus, almost no current flows to the resistance 20, and almost no current flows to a power line 15 as well. Further, the TRs 17 and 19 are used on common collector and common base, so there is almost no decrease in high-band amplification factor due to mirror effect.
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