IIIH
US006927762B2
(12) United States Patent (io) Patent No.: US 6,927,762 B2
Lin (45) Date of Patent: Aug. 9,2005
(54) APPLICATION SPECIFIC INTEGRATED CIRCUIT (ASIC) OF THE ELECTROMAGNETIC-INDUCTION SYSTEM
(75) Inventor: Chung-Chen Lin, Hsin-Chu (TW)
(73) Assignee: Aiptek International Inc., Hsin-Chu (TW)
( * ) Notice: Subject to any disclaimer, the term ol this patent is extended or adjusted under 35 U.S.C. 154(b) by 492 days.
(21) Appl. No.: 10/109,699
(22) Filed: Apr. 1, 2002
(65) Prior Publication Data
US 2003/0184530 Al Oct. 2, 2003
(51) Int. CI.7 G09G 5/00; G08C 21/00
(52) U.S. CI 345/174; 178/18.07
(58) Field of Search 345/173-180;
178/18.07, 18.08, 19.04; 455/566
(56) References Cited
U.S. PATENT DOCUMENTS
5,693,914 A * 12/1997 Ogawa 178/18.07
The electromagnetic-induction system ol the present invention comprises: a central processing unit (CPU); an application specific integrated circuit coupled with the central processing unit; a plurality ol analogy switches that are coupled with the central processing unit and the application specific integrated circuit, individually; an antenna loop coupled with a plurality ol analogy switches. The application specific integrated circuit lurther comprises: a digital filter that can reduce bandwidth error; a programmable gain amplifier that has the gain range with over eight-level; a latch device that can access the data at steady state; a multiplier and a divider that consist ol hardware to increase the report rate; a programmable frequency generator can output the signal with the stable frequency.
28 Claims, 3 Drawing Sheets
