PHYSICAL QUANTITY DETECTION DEVICE

To provide a physical quantity detection device capable of diagnosing disconnection or short-circuiting of wiring between a temperature detection element and an integrated circuit, and diagnosing that gas temperature to be detected is out of a guaranteed temperature range.SOLUTION: When an input voltage from a temperature detection element ranges from a first temperature TLL that is lower than a lower limit temperature TL of a guaranteed temperature range GTR, to a second temperature THH that is higher than an upper limit temperature TH of the guaranteed temperature range GTR, a temperature detection signal Tout that is proportional to gas temperature is output. When the input voltage is lower than the first temperature TLL, a constant first voltage VLL lower than a voltage VDL corresponding to the first temperature TLL is output. When the input voltage is higher than the second temperature THH, a constant second voltage VHH higher than a voltage VDH corresponding to the second temperature THH is output. When the input voltage is equal to or higher than the first temperature TLL and lower than the lower limit temperature TL, or exceeds the upper limit temperature TH and is equal to or lower than the second temperature THH, it is diagnosed as being out of the guaranteed temperature range GTR.SELECTED DRAWING: Figure 7 【課題】温度検出素子と集積回路との間の配線の断線または短絡を診断可能であり、検出対象の気体温度が保証温度範囲の範囲外であることを診断可能な物理量検出装置を提供する。【解決手段】温度検出素子からの入力電圧が保証温度範囲ＧＴＲの下限温度ＴＬよりも低い第１温度ＴＬＬから保証温度範囲ＧＴＲの上限温度ＴＨよりも高い第２温度ＴＨＨの場合に、気体の温度に比例した温度検出信号Ｔｏｕｔを出力する。入力電圧が第１温度ＴＬＬよりも低い場合に、第１温度ＴＬＬに対応する電圧ＶＤＬよりも低い一定の第１電圧ＶＬＬを出力する。入力電圧が第２温度ＴＨＨよりも高い場合に、第２温度ＴＨＨに対応する電圧ＶＤＨよりも高い一定の第２電圧ＶＨＨを出力する。入力電圧が第１温度ＴＬＬ以上かつ下限温度ＴＬ未満または上限温度ＴＨを超えかつ第２温度ＴＨＨ以下の場合に、保証温度範囲ＧＴＲの範囲外であることを診断する。【選択図】図７