| 摘要 |
PURPOSE:To eliminate the limit of a load circuit connected to a collector by feeding back a base current of a transistor(TR) whose emitter connects to a constant current source to a base of a differential amplifier circuit via a current mirror circuit to compensate the base current in the differential amplifier circuit used for a voltage input - current output amplifier circuit or the like. CONSTITUTION:An input voltage vi fed to input terminals 24, 25 is fed to a differential amplifier circuit 27 comprising NPN TRsQ26, Q27 and a constant current source 26 and an output current i0 is obtained from the collector of the TRQ27. The same current as the sum of base currents of the TRsQ26, Q27 is produced on the base of the NPN TRQ28 by the action of the constant current source 28 supplying the same constant current as the constant current source 26 and the base current is fed back to the bases of the TRsQ26, Q27 via TRsQ29, Q30 being components of the current mirror circuit 29 and PNP TRsQ31, Q32 to reduce the current flowing to the TRsQ26, Q27, Q31, Q32 and the collector potential of the TRsQ26, Q27 being components of the differential amplifier circuit has no limit. |
