Patent ID: 6218819
Filing Date: 2001-04-17
Classification: G05F

Abstract:
A voltage regulation device of the type that receives a voltage transmitted by radio-frequency at an input node and supplies a regulated voltage to electronic circuitry at an output node, said device comprising:a switching transistor coupled between the input node and the output node;a differential amplifier coupled to the switching transistor; andmeans for providing a stable predetermined voltage to the supply voltage input of the differential amplifier, the predetermined voltage being less than the voltage level at the input node and at least equal to the desired level of the regulated voltage plus the threshold voltage of the switching transistor,wherein when the voltage level at the output node is below a threshold voltage, the differential amplifier controls the switching transistor so as to substantially short-circuit the input node and the output node, andwhen the voltage level at the output node is not below the threshold voltage, the differential amplifier controls the switching transistor so as to substantially isolate the input node from the output node.