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:
May. 14, 1996
Filed:
Mar. 14, 1994
Michael L Bolan, Dallas, TX (US);
Clark R Williams, Plano, TX (US);
Dallas Semiconductor Corporation, Dallas, TX (US);
Abstract
An integrated circuit, in which some areas of the chip are powered from battery, but at least two other areas of the chip can draw power from independent on-chip power-storage capacitors (which are diode-isolated to accumulate charge from an external signal line). The signal line's input buffer draws power from one capacitor, and the decoder logic draws power from another. Thus, even if the first capacitor is depleted by the signal line's staying in the high-current regime, it will be powered up again when the signal line is again driven high; and the charge stored in the second capacitor will permit the decoding logic to operate. Preferably the second capacitor also powers circuitry which encodes a unique serial number for the chip. Thus, even after the battery has died, the chip can be interrogated to ascertain its unique serial number.