Oven-controlled crystal oscillator
AssigneeNihon Dempa Kogyo Co., Ltd.
InventorsJunichi Arai, Kenji Kasahara
Life of this patent
Estimating the term…
Abstract
An oven-controlled crystal oscillator includes a circuit board, a crystal unit surface-mounted on the circuit board, and a temperature control circuit that maintains operating temperature of the crystal unit constant. The temperature control circuit includes a heating resistor, a power transistor that supplies power to a heating resistor, and a temperature sensitive resistor that detects temperature of the crystal unit. The heating resistor is formed, as a film resistor, on a surface of the circuit board in an area thereof in which the crystal unit is located. The temperature sensitive resistor is provided on the circuit board as a film resistor.
Claims8
An oven-controlled crystal oscillator comprising:
- a crystal unit in which a crystal blank is hermetically encapsulated and which includes a pair of connection terminals provided on a bottom surface thereof and electrically connected to the crystal blank;
- an oscillating element forming an oscillation circuit together with the crystal unit;
- a temperature control circuit maintaining operating temperature of the crystal unit constant;
- and
- a circuit board on which the crystal unit is surface-mounted,
- wherein the temperature control circuit includes at least a heating resistor, a power transistor supplying power to the heating resistor, and a temperature sensitive resistor detecting temperature of the crystal unit, and
- the heating resistor is formed, as a film resistor, on the circuit board in an area of the circuit board in which the crystal unit is located, and
- the temperature sensitive resistor is formed on the circuit board as a film resistor.
Dependencies are inferred from the claim text.