An oscillator includes a first resonator element, a first circuit element configured to oscillate the first resonator element to generate a first oscillation signal, a first package which is configured to house the first resonator element and the first circuit element, and has a mounting surface and a mounting terminal disposed on the mounting surface, a second resonator element an oscillation frequency of which is controlled based on the first oscillation signal, and a second package which houses the second resonator element and is provided with the second package mounted on the mounting surface of the first package.

A crystal unit includes an AT-cut crystal element that has a planar shape in a rectangular shape and a part as a thick portion. The crystal element includes a first end portion, a depressed portion, the thick portion, and a second end portion in this order from a side of one short side in viewing a cross section taken along a longitudinal direction near a center of the short side. The depressed portion is a depressed portion disposed from the thick portion toward the first end portion side, depressed with a predetermined angle a and subsequently bulged, and connected to the first end portion.

An electronic part including an integrated circuit and a memory, the integrated circuit including a first clock terminal to which a clock signal is inputted, a first data terminal via which a first serial data signal is inputted and outputted, a second clock terminal via which the clock signal is outputted to the memory, a second data terminal via which a second serial data signal is inputted and outputted from and to the memory, and a first interface circuit including a control circuit that controls the communication state of the integrated circuit to be a first communication state in which the first serial data signal inputted to the first data terminal is outputted as the second serial data signal via the second data terminal or a second communication state in which the second serial data signal inputted to the second data terminal is outputted as the first serial data signal via the first data terminal.

A crystal unit includes an AT-cut crystal element that has a planar shape in a rectangular shape and a part as a thick portion. The crystal element includes a first end portion, a first depressed portion, the thick portion, a second depressed portion, and a second end portion in an order from a side of one short side in viewing a cross section taken along a longitudinal direction near a center of the short side. The first depressed portion is a depressed portion disposed from the thick portion toward the first end portion side, depressed with a predetermined angle a and subsequently bulged, and connected to the first end portion. The second depressed portion is a depressed portion disposed from the thick portion toward the second end portion side, depressed with a predetermined angle b and subsequently bulged, and connected to the second end portion.

An oscillator includes a resonation element, a first package that houses the resonation element and airtightly sealed, a circuit element that is positioned outside the first package and electrically connected to the resonation element, and a second package that houses the first package and the circuit element and sealed in a depressurized state. In addition, the first package includes a first base having a first recessed portion, and a first lid joined to the first base so as to close an opening of the first recessed portion, and the second package includes a second base having a second recessed portion and a second lid joined to the second base so as to close an opening of the second recessed portion. The circuit element is attached to the first base, and the first base is attached to the second base.

A crystal unit includes an AT-cut crystal element that has a planar shape in a rectangular shape and a part as a thick portion. The crystal element includes a first end portion, a first depressed portion, the thick portion, a second depressed portion, and a second end portion in this order from a side of one short side, in viewing a cross section taken along a longitudinal direction near a center of the short side. The first depressed portion is a depressed portion disposed from the thick portion toward the first end portion side, depressed with a predetermined angle a and subsequently bulged, and connected to the first end portion. The second depressed portion is a depressed portion disposed from the thick portion toward the second end portion side, depressed with a predetermined angle b and subsequently bulged, and connected to the second end portion.

An oscillator includes: a base substrate having a first electrode; a temperature control element mounted on the base substrate and having a first pad electrically coupled to the first electrode; a resonator element having a first major surface and a second major surface in front-back relation with the first major surface, and mounted on the temperature control element in such a way that the second major surface faces the temperature control element; and at least one first bonding wire coupling the first major surface and the first pad together.

An oscillator includes a first container that includes a first base substrate and a first lid bonded to the first base substrate and has a first internal space, a second container that is accommodated in the first internal space and fixed to the first base substrate, a resonator element that is accommodated in the second container, a temperature sensor that is accommodated in the second container, a first circuit element that is accommodated in the second container and includes an oscillation circuit oscillating the resonator element and generating an oscillation signal on which temperature compensation is performed based on a detected temperature of the temperature sensor, and a second circuit element that is fixed to the first base substrate and includes a frequency control circuit that controls a frequency of the oscillation signal, in which the second container and the second circuit element are arranged side by side in plan view.

An oscillator includes a first container, a second container accommodated in the first container, a resonator element accommodated in the second container, a temperature sensor accommodated in the second container, a first circuit element that is accommodated in the second container and includes an oscillation circuit that causes the resonator element to oscillate so as to generate an oscillation signal on which temperature compensation is performed based on a detected temperature of the temperature sensor, and a second circuit element which is accommodated in the first container and includes a frequency control circuit that controls a frequency of the oscillation signal. The second container and the second circuit element are spaced from each other and are disposed to overlap each other in plan view.

An oscillator includes a first container, a second container accommodated in the first container, a resonator element accommodated in the second container, a temperature sensor accommodated in the second container, a first circuit element that is accommodated in the second container and includes an oscillation circuit that causes the resonator element to oscillate so as to generate an oscillation signal on which temperature compensation is performed based on a detected temperature of the temperature sensor, and a second circuit element that is accommodated in the first container and includes a frequency control circuit that controls a frequency of the oscillation signal. The second container and the second circuit element are stacked.