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:
Feb. 18, 1986
Filed:
May. 12, 1982
Jerry M Collings, Santa Clara, CA (US);
Hybrid Systems Corporation, Billerica, MA (US);
Abstract
A successive approximation analog-to-digital converter utilizes an improved high-gain current comparator having a zero input impedance characteristic in combination with an equal current digital-to-analog converter. The zero input impedance comparator permits the use of low power C-MOS switching circuitry by leading the output of the digital-to-analog converter to the zero impedance input of the comparator, thereby overcoming the problem of decreased switching speed associated with high capacitance C-MOS outputs. The zero impedance current comparator includes an improved current-to-voltage converter having an overdrive shunt circuit to reduce quiescent current and to permit higher value load resistors for better gain; and cascaded current cells to provide increased gain.