Patent ID: 7808307
Filing Date: 2010-10-05
Classification: G05F

Abstract:
1. A reference current circuit, comprising: a current mirror circuit connected to a first power supply and generating first and second mirror currents at a predetermined current ratio, the first mirror current being distributed to first and second distributed currents while the second mirror current being distributed to third and fourth distributed currents; a first diode provided in a current path through which the first distributed current flows to a second power supply; a second diode provided in a current path through which the third distributed current flows to the second power supply; a first resistor provided in at least one of the current paths in which the first and third distributed currents flow; a second resistor provided in a current path in which an added current of the second and fourth distributed currents flows added and having one end connected to the second power supply; first to fourth transistors including drain electrodes on the first power supply side and source electrodes on the second power supply side of current paths in which the first to fourth distributed currents flow, respectively, wherein the first and third transistors control the first and third distributed currents to equalize a difference of potential differences between respective ends of the first and second diodes to a potential difference of ends of the first resistor, and the second and fourth transistors control a current ratio between the second and fourth distributed currents to be the predetermined current ratio.