Mechanism for minimizing current mirror transistor base current error for low overhead voltage applications

摘要

To mitigate against base current errors in a current mirror circuit that has limited overhead voltage, a compensated current mirror circuit includes a complementary polarity base current error reduction and auxiliary turn-on circuit, that provides an overhead voltage that enjoys a base-emitter diode drop improvement over the overhead voltage of a conventional circuit. Due to the base current error-reduction transistor in the circuit path from the power supply rail to the input port, the overhead voltage is improved by a base-emitter diode drop larger than the overhead voltage of the conventional circuit. In addition, it further reduces base current error.