公开(公告)号：EP2628241A1

公开(公告)日：2013-08-21

申请号：EP11754596.2

申请日：2011-08-31

Applicant: Xilinx, Inc.

Inventor： UPADHYAYA, Parag ,  KIREEV, Vassili

IPC: H03B5/12

CPC classification number: H03B5/1228 ,  H03B5/1212 ,  H03B5/124 ,  H03B5/1262 ,  H03B5/1265 ,  H03B2201/02 ,  H03B2201/0208 ,  H03B2201/0266

Abstract: A tunable resonant circuit (102) includes first capacitors (104, 108, 216, 228, 232) and second capacitors (106, 1 10, 218, 230, 234) that provide a matched capacitance between first and second electrodes of the first and second capacitors. A deep-well arrangement includes a first well (320, 326) disposed within a second well (322, 328) in a substrate (324). The first and second capacitors are each disposed on the first well. Two channel electrodes of a first transistor (120, 130) are respectively coupled to the second electrode (1 14, 304) of the first capacitor and the second electrode (1 18, 308) of the second capacitor. Two channel electrodes of a second transistor (122, 132) are respectively coupled to the second electrode of the first capacitor and to ground. Two channel electrodes of the third transistor (124, 134) are respectively coupled to the second electrode of the second capacitor and to ground. The gate electrodes (226, 314) of the first, second, and third transistors are responsive to a tuning signal (126, 136), and an inductor (144, 202) is coupled between the first electrodes (1 12, 1 16, 302, 306) of the first and second capacitors.