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:
Jul. 29, 2003
Filed:
Aug. 22, 2001
Joseph Weiyeh Ku, Palo Alto, CA (US);
Hewlett-Packard Development Company, L.P., Houston, TX (US);
Abstract
An analog performance monitoring method and circuit arrangement are adapted to count a plurality of digital event pulses. Each digital event pulse controls a switching circuit to pass a substantially fixed amount of charge from a power supply. The charge is accumulated in a capacitor. In one example embodiment, the switching circuit is a transistor biased by the capacitor voltage to operate in a constant current region. The capacitor has a capacity to accumulate charge added from at least 100,000 digital event pulses maintaining bias of transistor operation in the constant current region. A comparator circuit monitors capacitor charge and signals when a quantity of events adding charge to the capacitor reaches a selectable threshold. In another example embodiment, a programmable voltage divider provides a controllable threshold. A reset circuit discharges the capacitor to an approximate ground level. Sampling is used to estimate a population of digital event pulses.