Patent ID: 6690241
Filing Date: 2004-02-10
Classification: G11C

Abstract:
A semiconductor device for performing a prescribed operation in synchronization with a clock signal, comprising:an oscillator for producing said clock signal in which the oscillation frequency can be changed, said oscillator comprising: a plurality of inverters connected in a ring shape; and a variable capacitance circuit for each inverter in which the capacitance of each variable capacitance circuit can be changed, each variable capacitance circuit is connected to an output node of the corresponding inverter, and each variable capacitance circuit comprises a plurality of sets of transfer gates and capacitors connected in series between the output node of the corresponding inverter and a prescribed potential line; and setting means for changing and setting the oscillation frequency of said oscillator and for changing and setting the capacitance value of each variable capacitance circuit, said setting means comprising a fuse for each transfer gate for fixing the corresponding transfer gate at a conductive or non-conductive state by being disconnected.