| 摘要 |
PURPOSE:To realize a high frequency circuit with high accuracy comprising a current mirror circuit by controlling a potential at an input terminal of the current mirror circuit to be kept constant thereby eliminating the effect due to the fluctuation of a voltage VBE of the current mirror circuit. CONSTITUTION:Signal voltages V1-V6 are applied to input terminals 110-114 of a current mirror arithmetic circuit 100 via resistors R1-R5. A negative feedback control circuit 200 is inserted between a common terminal 105 and the input terminal 110 of the current mirror arithmetic circuit 100. The negative feedback control circuit 200 consists of a transistor (TR) 220 as a variable impedance element and a differential amplifier 210. Since the TR 220 is controlled so that the voltage at the input terminal 110 is made equal to the voltage of the reference input 211 of the differential amplifier 210 by the negative feedback control circuit 200, the voltages of the input terminals 111-114 having the constitution of the forward voltage nearly equal to each other are controlled to be constant.
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