A CURRENT SOURCE CIRCUIT

摘要

A current source for voltage regulators used in integrated emitter coupled logic (ECL) circuits to avoid variations in output current due to fluctuations in the voltage source. Transistors of one polarity type are employed. A current source (11) is connected to an output node (15). A transistor (Q2) generates a current proportional to the output voltage (15) to develop a voltage across a resistor (12) in turn controlling a transistor (Q3) in series with a resistor (14) and a diode connected transistor (Q4). By current mirror action the current flowing in transistor (Q4) is mirrored (IQ1) by transistor (Q1). The output current (I0) is the current flowing through resistor (11) less the current (IQ1).