| 摘要 |
PURPOSE:To decrease the chip area by providing a 1st switch circuit connecting to a resistor connected to a DC power supply and to each division node of a 1st division resistance string and a 2nd switch circuit connecting a resistor connected to ground and each division node of a 3rd division resistance string. CONSTITUTION:A DC power supply VCC is connected to a resistor R0 whose resistance is R/2, the resistor R0 is connected to division points a1-a4 of a 1st resistor string comprising resistors R1-R3 whose resistance is R via changeover switches 2-1-2-4 of the switch circuit 2. On the other hand, the earth point is connected to a resistor R10 whose resistance is R/2 and the resistor R10 is connected to division points a7-a10 of a 3rd resistor string comprising resistors R7-R9 whose resistance is R. Thus, number of connections with a selector 1 corresponding to the reference division resistor is reduced remarkably and the chip area is decreased.
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