Abstract: A PLL frequency synthesizer 1 according to one embodiment of the present invention is provided with a frequency divider 30, a phase comparator 40, a charge pump 50, a loop filter 60, a voltage controlled oscillator 70, and a changeover switch (within the switching unit 80). The loop filter 60 has a reference potential on a semiconductor substrate as a ground potential, and the changeover switch is formed on the semiconductor substrate 2 and switches connection between an intermediate node of the loop filter 60 and the reference potential on the semiconductor substrate 2 to switch the time constant of the loop filter 60.

Abstract: The phase comparison circuit according to an embodiment of the present invention comprises a fractional frequency divider 31 which generates a fractional frequency-divided signal Svn obtained by performing fractional frequency division on a clock on the basis of a control signal from a control circuit 32, a first integer frequency divider 33 which generates a first integer frequency-divided signal obtained by performing integer frequency division on the fractional frequency-divided signal Svn, a second integer frequency divider 34 which generates a second integer frequency-divided signal obtained by performing integer frequency division on a reference clock, a first selection circuit 35 which selectively outputs either the fractional frequency-divided signal Svn or the first integer frequency-divided signal on the basis of a switching signal, a second selection circuit 36 which selectively outputs either the reference clock or the second integer frequency-divided signal on the basis of the switching signal fr

Abstract: In a SAW device comprising a piezoelectric single crystal substrate and electrodes on a surface thereof, the substrate is obtained by slicing a LiTaO3 or LiNbO3 material such that a plane containing axis X and perpendicular to a new axis Y obtained by rotating axis Y about axis X by an angle of 33°±9° becomes the substrate surface, and each electrode is a layered film including a titanium nitride layer and an aluminum layer thereon. The aluminum layer containing no grain boundaries ensures high efficiency, long life SAW devices experiencing no increase of electrical resistance.

Abstract: A surface acoustic wave element includes a thin film electrode composed of monocrystal aluminum disposed on a piezoelectric substrate. At least one metal of Cu, Ta, W, and Ti is segregated in the thin film electrode composed of monocrystal aluminum. In this surface acoustic wave element, segregation of Cu or the like occurs in the thin film electrode. Such segregation is effective to reduce the occurrence of cracks on the piezoelectric substrate during ultrasonic wave connection for flip chip mounting. That is, because the occurrence of cracks on the piezoelectric substrate is reduced, tolerance against the ultrasonic vibration is advantageously improved in the surface acoustic wave element.

Abstract: In a SAW device comprising a piezoelectric single crystal substrate and electrodes on a surface thereof, the substrate is obtained by slicing a LiTaO3 or LiNbO3 material such that a plane containing axis X and perpendicular to a new axis Y obtained by rotating axis Y about axis X by an angle of 33°±9° becomes the substrate surface, and each electrode is a layered film including a titanium nitride layer and an aluminum layer thereon. The aluminum layer containing no grain boundaries ensures high. efficiency, long life SAW devices experiencing no increase of electrical resistance.

Abstract: In a SAW device comprising a piezoelectric single crystal substrate and electrodes on a surface thereof, the substrate is obtained by slicing a LiTaO3 or LiNbO3 material such that a plane containing axis X and perpendicular to a new axis Y obtained by rotating axis Y about axis X by an angle of 33°±9° becomes the substrate surface, and each electrode is a layered film including a titanium nitride layer and an aluminum layer thereon. The aluminum layer containing no grain boundaries ensures high efficiency, long life SAW devices experiencing no increase of electrical resistance.

Abstract: A surface acoustic wave element includes a thin film electrode composed of monocrystal aluminum disposed on a piezoelectric substrate. At least one metal of Cu, Ta, W, and Ti is segregated in the thin film electrode composed of monocrystal aluminum. In this surface acoustic wave element, segregation of Cu or the like occurs in the thin film electrode. Such segregation is effective to reduce the occurrence of cracks on the piezoelectric substrate during ultrasonic wave connection for flip chip mounting. That is, because the occurrence of cracks on the piezoelectric substrate is reduced, tolerance against the ultrasonic vibration is advantageously improved in the surface acoustic wave element.

Abstract: In a SAW device comprising a piezoelectric single crystal substrate and electrodes on a surface thereof, the substrate is obtained by slicing a LiTaO3 or LiNbO3 material such that a plane containing axis X and perpendicular to a new axis Y obtained by rotating axis Y about axis X by an angle of 33°±9° becomes the substrate surface, and each electrode is a layered film including a titanium nitride layer and an aluminum layer thereon. The aluminum layer containing no grain boundaries ensures high efficiency, long life SAW devices experiencing no increase of electrical resistance.

Abstract: To provide a buffer circuit that is able to achieve a reduction of the input current and a high input impedance by compensating the base current of a transistor, and to avoid a lowering of the input dynamic range by means of a current compensation circuit. By means of transistor P2, the base voltage of transistor Q2 is established in response to the signal of input node ND1 of the differential circuit, and the emitter voltage of transistor Q2 is set at virtually the same level as the reference voltage Vref. The collector current IC2 of transistor P2 is the same as the base current of transistor Q2, and is established with the amplification ratio of transistor Q2 as well as the current I2 of current source IS2.