PURPOSE: To improve the resolution of coefficient setting by using both a capacitor ratio and a switched capacitor type voltage divider in a switched capacitor type coefficient setting circuit.
CONSTITUTION: A coefficient setting part III having 1%-step is connected to an operational amplifier OP through a switched capacitor circuit I , a factor setting part II having 10%-step and 1/10 voltage divider A. An output voltage V0 can be set up by turning on coefficient setting switches SA1WSA9 and SB1WSB10 properly. The output voltage is determined on the basis of the total capacity of the switched capacitor circuits I WIII. Since a proper capacity ratio to be easily applied to IC and a simple voltage divider are used, a switched capacitor type coefficient setting circuit proper to a semiconductor integrated circuit having high resolution can be obtained.
KIDO MITSUYASU
KUDOU HIROYUKI
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