Patent ID: 7417415
Filing Date: 2008-08-26
Classification: G05F

Abstract:
1. A voltage-controlled current source for receiving a control voltage and using the control voltage to control an output current, the voltage-controlled current source comprising: an operational amplifier having a first input terminal for receiving the control voltage; a first transistor, wherein a gate terminal of the first transistor is coupled to an output terminal of the operational amplifier and a first source/drain terminal of the first transistor is coupled to a second input terminal of the operational amplifier; a second transistor, wherein a gate terminal of the second transistor is coupled to the output terminal of the operational amplifier and a first source/drain terminal of the second transistor outputs the output current; a resistor, wherein one terminal of the resistor is coupled to a first voltage line and the other terminal of the resistor is coupled to the first source/drain terminal of the first transistor; and a current mirror having a reference side input terminal and an output side output terminal, wherein the reference side output terminal is coupled to a second source/drain terminal of the first transistor and the output side output terminal is coupled to a second source/drain terminal of the second transistor.