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:
Mar. 02, 1999
Filed:
Mar. 24, 1997
Hajime Andoh, Shiga, JP;
Tadashi Ohmori, Tasu-gun, JP;
Timothy Joseph Schmerbeck, Kasson, MI (US);
Pantas Sutardja, San Jose, CA (US);
Denny Duan-Lee Tang, Saratoga, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
An analog-to-digital (A/D) converter capable of receiving a differential input for improved noise rejection and having two static resistive ladders for reducing power consumption. The resistive ladders are anti-parallel and have a high impedance, each dividing fixed voltages into a group of reference voltages. A first stage of comparators compares the positive signal of the differential input with each of the reference voltages from one of the resistive ladder, and the negative input signal with each of the reference voltages from the other resistive ladder. The outputs of the first stage of comparators are compared by a second stage of comparators to generate a group of binary outputs in parallel. An encoder converts the outputs of the second-stage comparators into a digital value. Decoupling capacitors are also provided to reduce the AC impedance of the resistive ladders.