US 4,785,231 AGranted

Reference current source

AssigneeTelefunken electronic GmbH

InventorsRolf Bohme, Jurgen Sieber

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Abstract

At a reference current source with two transistors and a controlled double current source, the base of the second transistor is connected to the collector of the first transistor, the emitter of the first transistor is connected to a reference point, the first terminal of the controlled double current source is connected to the first transistor, and the second terminal of the controlled double current source is connected to the collector of the second transistor. Either a first resistor is inserted between the base and the collector of the first transistor, and the emitter of the second transistor is connected to the reference point or the first resistor is inserted between the emitter of the second transistor and the reference point, and the base and the collector of the first transistor are connected to one another. A resistor is connected between the base of the first transistor and the reference point and/or a resistor is connected between the collector of the second transistor and the reference point.

Claims15

Dependent claims

A reference current source, comprising:

a controlled double current source, including a first terminal and a second terminal and means for producing a first current at said first terminal and a second current at said second terminal, the first and second currents being proportional to each other and proportional to a voltage across said first and second terminals;
a first transistor having its emitter connected to a reference point and its base connected to said first terminal;
a second transistor having its collector connected to said second terminal and its base connected to the collector of said first transistor;
first coupling means connecting the base of said first transistor to the collector of said first transistor, and second coupling means connecting the emitter of said second transistor to said reference point, one of said first coupling means and said second coupling means including a series connected resistor, and the other of said first coupling means and said second coupling means comprising a direct connection;
and
a second resistor connected between said reference point and one of the collector of said second transistor and the base of said first transistor.

3 more elements

Dependencies are inferred from the claim text.