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:
Apr. 26, 1983
Filed:
Nov. 03, 1980
Ernest A Carter, Austin, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A successive-approximation charge-redistribution analog-to-digital converter includes a binary weighted capacitive ladder for converting the least significant bits of the binary output representation and a resistive ladder for converting the higher order bits of the output representation. To achieve a half least significant bit shift, the capacitor of lowest capacitance in the ladder having a capacitance C is replaced by first and second capacitors each having a capacitance C/2. Each of these capacitors has a first terminal connected to the input of a comparator. Another input of the first capacitor is coupled to the low reference voltage. The second input of the second capacitor is coupled to one-eighth the high reference voltage during the sample phase and to the low reference voltage when the sample phase is completed. The resulting redistribution of charge which occurs at the input to the comparator is equivalent to minus one-half times the charge corresponding to one least significant bit. Thus, the stored sample to be converted is reduced in voltage by one-half least significant bit.