20120068871 | AD CONVERTER-EQUIPPED TEMPERATURE SENSOR CIRCUIT AND SEMICONDUCTOR INTEGRATED CIRCUIT - In an AD converter-equipped temperature sensor circuit, at start of operation, a successive approximation type AD converter converts an analog voltage having temperature dependence received from a voltage generation circuit, to determine all bits of the converted digital signal. Thereafter, a power control circuit detects only a change in the outputs of comparators into which reference voltages upwardly and downwardly adjacent to the potential of the analog voltage are input, and shuts off power supply to any comparator other than the above comparators. Thus, in sensing of a steady, slow-changing signal like the analog voltage having temperature dependence using the AD converter, power consumption is reduced and the signal processing time is shortened without degrading the resolution of the AD converter. | 03-22-2012 |