Current mirror for low supply voltage operation
AssigneeVTC Inc.
InventorsCraig M. Brannon, Tuan V. Ngo, John J. Price, Jr.
Life of this patent
Estimating the term…
Abstract
The present invention is an improved current mirror circuit. This improved current mirror circuit includes first and second transistors of the same conductivity type and have bases connected together. The first transistor is connected between a first supply terminal and an input terminal. The second transistor is connected between a first supply terminal and an output terminal. Included is a feedback circuit for providing a voltage feedback between the input terminal and the bases of the first and second transistors. Also included is a bias circuit for providing a bias current to the feedback circuit that is based on the input current.
Claims25
An improved current mirror circuit comprising:
- an input terminal having an input current and an input voltage associated therewith;
- an output terminal having an output current associated therewith;
- first and second supply terminals;
- first and second transistors of the same conductivity type having bases connected together with the first transistor being connected between the first supply terminal and the input terminals, and with the second transistor being connected between the first supply terminal and the output terminal;
- feedback means including third and fourth transistors of different conductivity types connected between the input terminals and the bases of the first and second transistors for providing feedback therebetween;
- and
- bias current means responsive to the input current for providing bias current to the feedback means based on the input current.
An improved current mirror circuit comprising:
- an input terminal having an input current and an input voltage associated therewith;
- an output terminal having an output current associated therewith;
- first and second supply terminals;
- first and second transistors of the same conductivity type having bases connected together with the first transistor being connected between the first supply terminal and the input terminal, and with the second transistor being connected between the first supply terminal and the output terminal;
- a feedback circuit including a third transistor having a control terminal and a pair of controlled terminals with the controlled terminals being connected between the first and second supply terminals and with the control terminal connected to the input terminal;
- and
- a current mirror bias circuit for providing bias current in the third transistor based on the input current.
An improved current mirror circuit comprising:
- an input terminal;
- an output terminal;
- first and second supply terminals;
- first and second transistors of the same conductivity type having bases connected together with the first transistor being connected between the first supply terminal and the input terminal, and with the second transistor being connected between the first supply terminal and the output terminal;
- a third transistor connected between the first and second supply terminals and having a base connected to the input terminal;
- a fourth transistor connected between the bases of the first and second transistors and the second supply terminal and having a base connected to an emitter of the third transistor;
- and
- current mirror means for providing a current in the third transistor based on current in the first transistor.
Dependencies are inferred from the claim text.