TEMPERATURE COMPENSATED CRYSTAL OSCILLATOR

摘要

PURPOSE: A temperature compensated crystal oscillator is provided to make a frequency of high-temperature stable by connecting a variable resistor to a fixed resistor to construct the temperature compensated crystal oscillator. CONSTITUTION: A high-temperature compensating circuit(110) and a low-temperature compensating circuit(120) compensate a capacitance changed by the temperature. A crystal resonator(130) resonates a predetermined frequency by the capacitances of the high-temperature compensating circuit and the low-temperature compensating circuit and a capacitance and an inductance thereof. An oscillating circuit(140) oscillates the resonated frequency by the crystal resonator. The high-temperature compensating circuit(110) is constructed by connecting the first thermistor(111) which represents a resistance value according to the temperature and the first variable resistor(113) serially and connecting the first capacitor to it parallel. The low-temperature compensating circuit(120) is constructed by connecting the second thermistor(121) which represents the resistance value according to the temperature, the second variable resistor(123) and the second capacitor parallel.