| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for applying a reference voltage more properly when a temperature is to be detected with the utilization of a temperature dependency of a threshold value of a MOSFET. SOLUTION: A longitudinal MOSFET 21 a temperature of which is to be detected, a temperature detection cell 22 and a reference voltage cell 23 are formed in the same semiconductor substrate, thereby to constitute a field effect transistor 101 with a built-in temperature detection part. Each of the temperature detection cell 22 and the reference voltage cell 23 is formed as a lateral MOSFET in the same well region. The temperature detection cell 22 is driven with a constant current of a drain current I2 showing a temperature dependency in a gate-source voltage VGS to a drain current ID characteristic. The reference voltage cell 23 is driven with a constant current of a drain current I3 not showing the temperature dependency. A temperature is detected by a comparator 103 in accordance with a difference of output voltages from the temperature detection cell 22 and reference voltage cell 23. |
