(19)

(11)

EP 1 800 397 A1

(12)

(43) Date of publication: 27.06.2007 Bulletin 2007/26 (21) Application number: 05783097.8 (22) Date of filing: 12.09.2005

(51) International Patent Classification (IPC):  H03F 1/56(2006.01) H03F 3/45(2006.01) H03F 3/19(2006.01) H03D 7/14(2006.01) (86) International application number: PCT/GB2005/050149 (87) International publication number: WO 2006/032932 (30.03.2006 Gazette 2006/13)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR (30) Priority: 20.09.2004 GB 0420841 03.12.2004 US 633104 P (71) Applicant: Frontier Silicon Limited Cambridge Cambridgeshire CB2 4LJ (GB)	(72) Inventor: Troop, Nicholas Mark, c/o Frontier Silicon Limited Cambridge, Cambridgeshire CB2 4LJ (GB) (74) Representative: Martin, Philip John  Marks & Clerk 66-68 Hills Road Cambridge, Cambridgeshire, CB2 1LA Cambridge, Cambridgeshire, CB2 1LA (GB)