Patent ID: 6239652
Filing Date: 2001-05-29
Classification: G05F

Abstract:
An internal voltage fall-down circuit comprising:a reference voltage generating means for variably generating an optimum reference voltage level which is compensated for depending on chances in the present reference voltage before fuse blowing;a reference voltage transforming means for receiving said reference voltage from said reference voltage generating means and then transforming said reference voltage into voltage for a normal mode or a stress mode which are presently set; anda driver means for providing the signal from said reference voltage transforming means to an internal circuit as an internal supply voltage;wherein said reference voltage generating means includes:a reference voltage generator for generating a first constant reference voltage,a comparator for comparing a final preset reference voltage feedbackedly received with said first reference voltage from said reference voltage generator,a current driver for providing a given final reference voltage to said reference voltage transforming means in response to an output of said comparator,a voltage regulator for variably regulating the final reference voltage and outputting a regulated voltage to said comparator, anda variable controller comprising a fuse detecting section for detecting fuse signals; a pad signal detecting section for detecting pad signals; a selecting section for selecting any one of said fuse signal detecting section and said pad signal detecting section by detecting said pad signal; and a control signal output section for combining the signals from said fuse signal detecting section and said pad signal detecting section to output control signals for said voltage regulator.