Patent ID: 6268776
Filing Date: 2001-07-31
Classification: H03B

Abstract:
A tunable crystal oscillator comprising:an oscillator circuit including at least one tuning capacitance circuit that comprises:a switched capacitor array having K columns of switchable capacitors, numbered k=1, 2, . . . , K, where K is a selected positive integer at least equal to 2.sup.M, where each column has N switchable capacitors, numbered n=1, 2, . . . , N, with selected capacitance values, where M and N are selected positive integers satisfying M+N.gtoreq.9, where each capacitance value in column number k is a multiple of a selected base value C(k), the base values satisfy C(k)<C(k+1) (k=1, 2, . . . , K-1), and for at least one positive integer k=k0, the ratio C(k0+1)/C(k0) is not an integer; andan address circuit, connected to the K columns and to the switchable capacitors within each column, that specifies a column and specifies switching of selected capacitors within the specified column by specification of at least M+N bits, and thereby controls the capacitance of the tuning circuit.