| 摘要 |
A temperature characteristic compensating circuit is capable of carrying out temperature compensation of a signal that varies in proportion to absolute temperature by analog processing and without using a thermistor, to thereby enable use of a smaller IC. A first current source supplies a first current that is proportional to the absolute temperature and inversely proportional to the resistance value of a first resistor. A second current source supplies a second current that is inversely proportional to the resistance value of a second resistor. A first circuit carries out logarithmic compression of an input voltage using the first current as a bias current, and a second circuit carries out logarithmic expansion of the logarithmically compressed voltage using the second current as a bias current. The gain of the logarithmically expanded voltage relative to the input voltage is proportional to the ratio of the second current to the first current. As a result, a temperature characteristic compensating circuit that does not use an external thermistor but nevertheless gives a gain inversely proportional to absolute temperature can be formed.
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