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. 14, 1995
Filed:
May. 03, 1993
Yunn-Hwa Wang, Taipei, TW;
Industrial Technology Research Institute, Hsinchu, TW;
Abstract
In an autozero type MOSFET comparator, the spurious current induced by the high frequency input voltage can flow through the resistance of the reset switch to introduce an offset voltage error during the autozero mode. A canceler is used to prevent the spurious current from flowing through the reset switch. A T-network with two series capacitors and a shunt switch is used as the canceler. The spurious current is by-passed by the shunt switch and prevented from flowing through the reset switch placed at the output of the T-network. The spurious current canceler is particularly useful for a sub-ranging ADC, where the comparator is used also as a sample-and-hold circuit to hold the input voltage across the series capacitors by opening all the sampling switches, the reset switch and the shunt switch.