Patent ID: 6693415
Filing Date: 2004-02-17
Classification: G05F

Abstract:
A current source, comprising:a sensing transistor having a control electrode and a main current path; a bandgap circuit having first and second control transistors and a first current mirror, each of the first and second control transistors having respective control electrodes, respective emitters and respective collectors, the first current mirror having a diode-connected transistor and a controlled transistor, the diode-connected transistor connecting the collector of the first control transistor to a power rail and the controlled transistor connecting the collector of the second control transistor to the power rail; a feedback resistance having a first end connected to the main current path at a first node, and a second end at a reference potential, the first node being connected to the control electrodes of the first and second control transistors; a first resistance coupling the emitter of the first control transistor to the reference potential; a second resistance coupling the emitter of the second control transistor to the emitter of the first control transistor, the bandgap circuit being dimensioned to provide a first potential across said feedback resistance; and a current amplifier having an input and an output, the input being connected to the collector of the second control transistor and the output being connected to the control electrode of the sensing transistor.