| 摘要 |
PURPOSE:To improve the response and to save power, by providing a switching element with a signal system directly and switching the power supply, in switching the power supply of an output transistor (TR) in response to an input signal level. CONSTITUTION:An input signal Si in phase-inversion is inputted to a terminal 7 and it is applied to the base of a TR6 connected to a power supply terminal 1 via a resistor 5. The emitter of the TR6 is connected to a power supply terminal 2 via a varistor 8 and a constant current source 9. The TR6 is conductive at a positive half cycle of the signal Si, the TRs11,12 are operated and the TR6 is nonconductive at a negative half cycle, the TRs15,16 are operated and output is given to a load resistor 20. With this constitution, before the TRs11,12 supplied from the low potential power supply of the terminal 2 are saturated through the increased level of the signal Si, a power supply switching TR22 is conductive and switching is made to the high potential power supply of the terminal 1. Similar switching is made even at a negative half cycle. Thus, the response can be improved and the power can be saved. |
