| 摘要 |
PURPOSE:To attain level detection with excellent temperature characteristic by applying an output of the 1st current source of band gap type and the 2nd constant current source with compensation to an emitter of a limit amplifier circuit and a differential amplifier of a level detection circuit respectively. CONSTITUTION:A constant current IA having a positive temperature coefficient (+3,000ppm/ deg.C) by a VT is applied from a band gap type constant current source circuit 5 to a limit amplifier circuit 1 and a constant current IC obtained by cancelling a constant current IA of the band gap type constant current source circuit 5 by a constant current IB having a negative temperature coefficient (n=3,000ppm/ deg.C) by a base-emitter voltage VBE of a transistor Q of a constant current source 7 with compensation is applied to a rectifier circuit 2 of the level detection circuit so as to zero both the voltage gain of the limit amplifier circuit and the temperature coefficient of the rectified output thereby obtaining the level detection signal Vdet with excellent temperature characteristic.
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