Patent ID: 6420859
Filing Date: 2002-07-16
Classification: G05F

Abstract:
A voltage supply controller, suitable for use for a low operation voltage device comprising a voltage source receiving terminal, the low operation voltage device outputting an operation enable signal during operation, the voltage supply controller comprising:a first transistor, comprising a gate and a first source/drain region coupled to a high voltage, and a second source/drain region coupled to the voltage source receiving terminal, the first transistor having a first threshold voltage; and a second transistor, comprising a first source/drain region coupled to the high voltage, a gate to receive the operation enable signal, and a second source/drain region coupled to the voltage source receiving terminal, the second transistor having a second threshold voltage lower than the first threshold voltage; wherein when the low operation voltage device is not operated, the second transistor is cut off, and the voltage drop of the high voltage received at the voltage source receiving terminal is controlled by the first transistor, and when the low operation voltage device is operated, the operation enable signal conducts the second transistor to control the voltage drop of the high voltage.