| 摘要 |
PURPOSE:To obtain a circuit where the accuracy of coincidence between an input current and an output current is excellent even when transistors (TRs) with a small current amplification factor are employed by adding a current mirror circuit comprising TRs Q4, Q5 and resistors R1, R2 to a conventional current mirror circuit so as to apply current feedback to common bases of the TRs Q1, Q2 from a collector of a TR Q3. CONSTITUTION:The current mirror circuit 10 comprising the TRs Q4, Q5 and the resistors R1, R2 is added, a current I3 is fed back to the common bases of the Trs Q1, Q2, a current input terminal of the current mirror circuit 10 is connected to the collector of the TR Q3 and a current output terminal is connected to the common bases of the TRs Q1, Q2 respectively. Suppose that the Trs Q1-Q3 have all equal characteristics. The current Ii inputted from the input terminal is divided into currents IC1, I2, and the current IC1 is the collector current of the TR Q1. Since the bases of the TR Q1, Q2 are connected in common and each emitter is connected to an equal potential point, the collector current LC1 of the TR Q1 and the collector current IO of the TR Q2 are equal. The current IO is used as the output current.
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