CURRENT MIRROR CIRCUIT

PURPOSE:To realize the current mirror circuit having an optional input/output current ratio with high precision in which an error in a current ratio by a base current is compensated. CONSTITUTION:The current mirror circuit is provided with a mirror circuit 1 comprising transistors(TRs) Q1-Q3, a current conversion circuit 2 and a bias power supply 3. An emitter area ratio of the TR Q2 of the mirror circuit 1 is selected to be a multiple of N of that of the TR Q1 and an emitter current of the TR Q2 is selected to be a multiple of N of the emitter current of the TR Q1. Then a collector of the TR Q2 is connected to the emitter of the TR Q3 and the collector of the TR Q3 is connected to a current output terminal B. An input terminal D of the current conversion circuit 2 is connected to the base of the TR Q3 and an output terminal E is connected to the collector of the TR Q1. Then a ratio of an output current to the output terminal E to the input current from the input terminal D of the current conversion circuit 2 is set to N:(N+2).