| 摘要 |
PURPOSE:To employ even an inexpensive thermosensing element with inferior linearity by reading a data from a temperature compensation data group written in a nonvolatile memory in response to an output electric quantity generated at any time from the thermosensing element and supplying the data to a crystal oscillator. CONSTITUTION:The thermosensing element 12 such as a thermister whose output electric quantity varies along with a specific temperature coefficient curve in response to external ambient temperature, an A/D converter 13 and a P-ROM 14 are connected in series. Then a crystal oscillator 11 is connected to the ROM 14 via a D/A converter 15, a setting value is written in the ROM 14 and a desired oscillation output is outputted from the oscillator. In the circuit above, an optimum temperature compensation data group with respect to the oscillator 11 in pairs. with the element 12 is written in advance in the ROM 14 in response to the output electric quantity generated from the element 12. Then the corresponding temperature compensation data is read from the ROM 14 in response to the electric quantity generated from the element 12 under the actual operation and it is supplied to the oscillator 11 to compensate the temperature of the oscillator 11.
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