| 摘要 |
PURPOSE:To cancel the offset between input and output voltages of a buffer amplifier by detecting a halved drive current and driving an active load based on the detected current. CONSTITUTION:A constant current source 14 is provided in relation to a constant current source 4 and the constant current source 14 is constituted to flow a current I1 thereto being a half with respect to a current value 2I1 of the constant current source 4. The constant current source 14 is connected to a power terminal 6 through transistors (TRs) 15, 16 constituting the diode side of a current mirror. Then the TR side of the said current mirror is used as a TR 7 for the active load. Since the TR at the diode side of the current mirror is not connected to a collector of the TR 2 in this circuit, the possibility of the generation of an offset voltage due to the base current of the current mirror is precluded.
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