| 摘要 |
PROBLEM TO BE SOLVED: To provide a circuit configuration which can reduce an area of a chip which constitutes a constant current circuit. SOLUTION: A starting element for feeding a base current of a transistor 6 is constituted with a Zener diode 7, and diffusion layers 20-22, which constitute the Zener diode 7, are each set to an impurity concentration which generates a leak current. Consequently, the Zener diode 7 feeds a current equivalent to a leak current and generates a potential difference (Vz×the number of Zener diodes 7) between both ends of the Zener diode 7 so as to serve as a resistor. Thus, a necessary area can be decreased by constituting the starting element with the Zener diode 7 compared with the case of constituting the starting element with a resistor. Therefore, it is possible to achieve a circuit composition which can reduce an area of a chip constituting a constant current circuit. COPYRIGHT: (C)2007,JPO&INPIT
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