Current mirror circuit
AssigneeMotorola, Inc.
InventorWilliam Eric Main
Life of this patent
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AssigneeMotorola, Inc.
InventorWilliam Eric Main
Estimating the term…
A current mirror circuit (31) that includes an active loop which operates transistors of different conductivity type at equal base-emitter junction voltages to minimize error. A first resistor (38) couples to a base of a first transistor (32) of a first conductivity type in a voltage follower configuration. A reference current is coupled to the first resistor (38). The voltage across the first resistor (38) and base-emitter junction of the first transistor (32) is mirrored across the base-emitter junction of a second transistor (34) of a second conductivity type and a second resistor (39). A third transistor (35) of the second conductivity type in a diode configuration is coupled to receive current from the second transistor (34). The voltage across the third transistor (35) biases a fourth transistor (33) of a first conductivity type. The current from the fourth transistor (33) is provided to the first transistor such that the first and second transistors (32,34) operate at equal base-emitter voltages.
A current mirror having an input for receiving a reference current and an output for providing an output current, the current mirror comprising:
A method of increasing accuracy of a current mirror wherein the current mirror comprises transistors of different conductivity type, the method including a step of operating the transistors of different conductivity type having identical base-emitter junction voltages to minimize current mirror error.
A current mirror having an input for receiving a reference current and an output for providing an output current, the current mirror comprising:
A current mirror having an input for receiving a reference current and an output for providing an output current, the current mirror comprising:
Dependencies are inferred from the claim text.