Kawasaki Microelectronics, Inc.

Takahito Fukushima

Isamu Kuno

Ryuji Ariyoshi

Junji Aoike

A clock generating circuit includes a delay circuit which has input terminals and which delays a signal input from each of the input terminals by a different delay time, and outputs the delayed signal from at least one output terminal, a selective circuit which receives an input clock signal and selectively outputs the clock signal to one of the input terminals of the delay circuit, and a control circuit which switches selective operations of the selective circuit. A modulated clock signal in which the period of the clock signal is increased or decreased is output from the at least one output terminal of the delay circuit such that the control circuit sequentially switches the selective operations of the selective circuit.

Spread spectrum clock generating circuit

A semiconductor integrated contains a first MOS transistor of a first conductivity type formed on a surface of a semiconductor substrate, and a second MOS transistor of the first conductivity type having a drain-source breakdown voltage lower than that of the first MOS transistor. The second MOS transistor is used as an anti-fuse, which can be changed to a conductive state with a low writing voltage that does not damage the first MOS transistor. The second MOS transistor is fabricated such that a concentration of a second conductivity type impurity in at least a portion of the channel region adjacent to the drain region is higher than that in a corresponding portion of the first MOS transistor.

Growing community of inventors

Chiba, Japan

Takahito Fukushima