The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 07, 2000
Filed:
Sep. 10, 1998
Uday Dasgupta, Singapore, SG;
Tritech Microelectronics, Ltd., Singapore, SG;
Abstract
A circuit and a method are disclosed which offer a solution for integrating a power-on-reset circuit that is realizable in a small space, consumes very little power, and works for practically any rate of rise of the power supply. These goals have been achieved by detecting, in a first section of the circuit, when the supply voltage reaches the threshold voltage V.sub.TP of a p-channel transistor, and activates power-on-reset by forcing that signal to logical zero (active). This first section detects next when the supply voltage reaches 2V.sub.TP and signals to a second section of the circuit to start charging a capacitor. The charging rate of the capacitor is controlled in such a way that its voltage lags behind the supply voltage, so that if the rise of the supply voltage is very fast, the duration T.sub.D of power-on-reset is long enough to insure complete resetting of the circuits it serves, such as digital memory elements, digital registers etc. A third section of the circuit monitors the voltage of the capacitor and when this capacitor voltage has reached a certain predetermined percentage of the supply voltage, this third section terminates power-on-reset by switching that signal to logical one (inactive).