| 摘要 |
PURPOSE:To accurately detect a deviation from a current value corresponding to the reference voltage of a load current at all times by providing a main MOSFET, a subordinate MOSFET, a detection resistance, etc. CONSTITUTION:When both MOSFETs 30 and 40 conduct by receiving a signal from a driving means 10, the majority of the load current to a load flows to the input terminal 35 of the main MOSFET 30 through many cells and an output terminal. The remaining part of the load current, on the other hand, flows through the input terminal of the subordinate MOSFET 40, a cell output terminal, and the detection resistance 50, which detects the inflow current and generate a detection voltage. This detection voltage and a voltage from a reference voltage generator 60 are supplied to a comparator 70 and compared with each other. Further, the resistance 50 is formed of a material which has negative resistance temperature characteristics. Consequently, the resistance value of the resistance 50 varies according to the negative temperature characteristics so that even if the MOSFETs 30 and 40 and resistance 50 vary in temperature, variation in the internal resistance value of the MOSFET 40 with temperature is canceled, so the detection voltage from the resistance 50 is held at the same value.
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