Current source with low supply voltage and weak sensitivity to voltage, for use in electronic integrated circuits and parts of circuits, e.g. in operational amplifiers

摘要

The current source comprises a driver branch (114) with a resistor (118) for the current setting, at least one slave branch (116), and a mirror-current (120) with transistors (121, 122) coupling the two branches. The current source also comprises a transistor (151) as the means for injecting a current proportional to that in the driver branch into the resistor (118), and a transistor (152) as the means for injecting a current proportional to that in the slave branch into a resistor (142) of degeneration of the mirror-current transistor (122). The transistor (151) has the emitter surface greater than that of the transistor (121) of the driver branch of the mirror-current. The transistor (152) connected to the degeneration resistor (142) of the slave branch forms a mirror-current with a source transistor (112) connected in the slave branch. The transistor (152) has the emitter surface greater than that of the source transistor (112) of the slave branch.