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:
Nov. 02, 2004
Filed:
Oct. 14, 2003
Ethan A. Crain, Cambridge, MA (US);
Karl Rapp, Los Gatos, CA (US);
Etan Shacham, Cupertino, CA (US);
Fairchild Semiconductor Corporation, South Portland, ME (US);
Abstract
A low read current, low power consumption sense amplifier well suited for low frequency RFID systems is disclosed. An MOS transistor receives the read current from a memory cell, typically an EEPROM, and a current mirror is formed by a parallel MOS transistor. The mirror current is integrated on a capacitor after the charge on the capacitor is cleared via a reset pulse. A time period is defined during which the voltage on the capacitor is compared to a second voltage. The second voltage is formed from a reference voltage or from dummy cells, in either case the reference voltage is at about the logic boundary between a one and zero stored in a memory cell. A comparator, with or without input hysteresis, receives the voltage on the capacitor and a second voltage and within the time period, the output state of the comparator indicates the binary contents of the memory cell.