A variable frequency oscillator comprising a first transistor (10) and a second transistor (20); wherein the first transistor (10) has a first terminalcollectorwhich is connected to a reference voltage, and a second terminalemitterwhich is connected to a first terminal of a first current source (13), which second terminal is connected to ground, and a third terminalbaseconnected to a first terminal of a first inductor (14) and to a top terminal of a first capacitor (11), wherein the first capacitor (11) has a bottom terminal which is connected to the second terminalemitterof the first transistor (10) but also to a top terminal of a second capacitor (12) having a bottom terminal being connected to ground; wherein the second transistor (20) has a first terminalcollectorwhich is connected to a reference voltage, and a second terminalemitterwhich is connected to a first terminal of a second current source (23), which second terminal is connected to ground, and a third terminalbaseconnected to a first terminal of a second inductor (14) and to a top terminal of a third capacitor (21), wherein the third capacitor (21) has a bottom terminal which is connected to the second terminalemitterof the second transistor (20) and also to a top terminal of a fourth capacitor (22) having a bottom terminal connected to ground; wherein the first and second inductors (14, 24) have a second terminal which are connected via a circuit (100) achieving variable capacitance, so as to form a circuit connecting in series all passive components composing the LC tank, so as to achieve a variable capacitance which can be used for performing a tuning of the oscillator, and wherein the second capacitor (12) and the fourth capacitor (22) are both connected to the physical ground thereby avoiding a 2nd harmonic common mode oscillation that might dominate over the differential fundamental one and might destroy the first and the second transistors (10, 20).

An oscillation circuits that provides stable oscillations even when the amount of phase rotation of a piezoelectric resonator is small or fluctuates. The oscillation circuit includes a first amplifier having an input and an output, and a piezoelectric resonator connected between the input and the output of the first amplifier. Moreover, the oscillation circuit feeds, back to the input, a current flowing from the output of the first amplifier to the piezoelectric resonator. The oscillation circuit further includes an alternating-voltage waveform shaping circuit that applies, to the piezoelectric resonator, an alternating-voltage waveform having rising portions sharper than those of a sine wave.

An integrated circuit device includes a substrate, a joining part provided on the substrate and joined to a vibrator, and a plurality of bonding pads provided on the substrate. The joining part includes an insulating protective film that covers a part of a surface of the substrate, and no insulating protective film is provided between the adjacent bonding pads.

The invention relates to an electric circuit of a generator of oscillations, comprising an enhancement-mode field transistor T1, inductance L1 and resistance R1 connected to the source or the drain of the transistor T1, characterized in that the inductance L1 is connected directly between the gate and the drain of the transistor T1 or to an electric circuit of a generator of oscillations, comprising an depletion-mode field transistor T1, inductance L1 and resistance R1 connected with its one end to the source of the transistor T1, characterized in that the inductance L1 is connected directly between the gate of the transistor T1 and the other end of the resistance R1.

An oscillator includes a front side voltage divider, a rear side voltage divider, and an oscillation unit. The front side voltage divider includes a first resistor connected between a first and second potential sources, and a first output terminal configured to changeably connect to a connection position in the first resistor so as to vary an obtained output voltage. The rear side voltage divider includes a second resistor connected between the first output terminal and a third potential source; and a second output terminal configured to changeably connect to a connection position in the second resistor so as to vary an obtained output voltage. The oscillation unit includes a variable capacitance element with a capacitance varied according to the output voltage from the second output terminal. The oscillation unit varies an output frequency based on a variation in a resonance point associated with a variation in the capacitance.

The oscillation circuit 1 comprises: an oscillator X1; a first capacitance CF having one end connected to the oscillator X1; a second capacitance CO having one end connected to the other end of the first capacitance CF; an output terminal Vo connected to a connection point N2 of the first capacitance CF and the second capacitance CO; an amplifier circuit A1 connected between a node between the oscillator X1 and the first capacitance CF and a connection point N2 of the first capacitance CF and the second capacitance CO to form an oscillation loop together with the first capacitance CF; a differential amplifier circuit A2 arranged on the oscillation loop; and a feedback path 3 configured to feed a part of an output on the output terminal Vo to the differential amplifier circuit A2.

An oscillation circuit which includes a Pierce circuit and a Colpitts circuit that share an oscillator and an input node to respective amplifiers and switches connected to output nodes of the respective amplifiers of the Pierce circuit and the Colpitts circuit. The switches are controlled to cause the oscillation circuit output oscillation signals of the Pierce circuit at the time of oscillation start-up and output oscillation signals of the Colpitts circuit at the time of steady-state oscillation.

The oscillation circuit 1 comprises: an oscillator X1; a first capacitance CF having one end connected to the oscillator X1; a second capacitance CO having one end connected to the other end of the first capacitance CF; an output terminal Vo connected to a connection point N2 of the first capacitance CF and the second capacitance CO; an amplifier circuit A1 connected between a node between the oscillator X1 and the first capacitance CF and a connection point N2 of the first capacitance CF and the second capacitance CO to form an oscillation loop together with the first capacitance CF; a differential amplifier circuit A2 arranged on the oscillation loop; and a feedback path 3 configured to feed a part of an output on the output terminal Vo to the differential amplifier circuit A2.

An oscillator is proposed that can produce much greater voltage than the input voltage. To accomplish this, the coil and the capacitor in the tank circuit are connected in series. This creates a high voltage point between the capacitor and the coil. However, in order to work it requires a special feedback method. Like the Hartley and Armstrong oscillators, it draws energy from the coil in the tank circuit, except it is accomplished by a separate coil placed a given distance away from the coil in the tank circuit. Ultimately this oscillator has advantages when high power is needed. It has a small component count and is easy to build. Currently if one wants to have high power oscillation, one uses a low voltage signal generator and then goes through several steps to amplify the signal. Here the oscillator already produces the high voltage. Another advantage in the design is that since the feedback has to provide the right amount of energy, this can be adjusted to the optimal feedback by manually adjusting the distance between the coils. Another advantage is that, when aligning the coils correctly, the oscillator produces a virtually perfect sine wave.