| 摘要 |
PURPOSE:To suit a power amplifying circuit for integration while improving reliability by eliminating the simultaneous conduction of upper-and lower-stage output transistors by increasing a minimum operation output voltage above the collector- emitter saturation voltage of a post-stage transistor among lower-stage output transistors. CONSTITUTION:When collector-emitter saturation voltage VCE(sat) of single-ended push-pull SEPP output lower-stage output transistor Q6 is nearly twice its base- emitter voltage VBE, collector-emitter voltage VCE of transistor Q6 never drops below 2VBE+VCE(sat) and transistor Q6 will not get saturated. On the other hand, when VCE(sat) of transistor Q6 is approximate three times its base-emitter voltage, VCE of transistor Q6 never drops below 3VBE+VCE(sat), so that transistor Q6 can be left unsaturated. Then, transistor Q6 can be used in the unsaturated state, so that transistors Q3 and Q6 can be prevented from turning on simultaneously. |
