Temperature-compensated crystal oscillator

A temperature-compensated crystal oscillator of a surface mount type comprising:

• an integrated circuit which has at least a power supply terminal, an output terminal, and an automatic frequency control voltage input termial;
• and
• a crystal blank as a crystal unit, wherein said integrated circuit and said crystal blank are accommodated into a container and hermetically sealed in the container, said container provided with respective mounting terminals corresponding to said power supply terminal, said output terminal, and said automatic frequency control voltage input terminal,
• said integrated circuit comprising:
• an oscillation circuit which is integrated in the integrated circuit and connected to said crystal unit to form an oscillation closed loop;
• and
• a damping resistor which is provided outside the oscillation closed loop and connected to at least one terminal of said power supply terminal, said output terminal, or said automatic frequency control voltage input terminal for reducing resonance acuteness of a parasitic resonance circuit which is produced by inductance which occurs when mounting said temperature-compensated crystal oscillator on a wiring board via the mounting terminals and stray capacitance which exists in a vicinity of said at least one terminal,
• wherein said temperature-compensated crystal oscillator compensates a frequency-temperature characteristic of the crystal unit to output a frequency signal,
• wherein said integrated circuit is further provided with a protection circuit for preventing electrostatic breakdown having a parasitic capacitance;
• and
• wherein said damping resistor is inserted between said at least one terminal and said protection circuit, said damping resistor being independent of said protection circuit.