PURPOSE: To make a switched capacitor circuit into an LSI by providing a capacity having a switching means in parallel between a signal input terminal and the inverted input terminal of an operational amplifier to set the capacity of a desired transfer function to a negative value.
CONSTITUTION: The capacitor circuit consists of first and second operational amplifiers OP1 and OP2, integral capacities C21 and C22, first∼seventh capacities K22∼K27, and first eighth switching means SW1∼SW8. In this constitution, the seventh switching means SW7 connects a signal input terminal Vin or a common potential point to one end of the seventh capacity K27 by switching, and the eighth switching means SW8 connects the inverted input terminal of the operational amplifier OP2 or the common potential point to the other end of the seventh capacity K27 by switching. Means SW1∼SW8 are driven by two-phase clocks, and a set of means SW1, SW3 and SW7 and a set of means SW2, SW4, SW5, SW6 and SW8 are switched and alternately driven in opposite phase relations. An input signal is inputted from the terminal Vin, and an output signal is outputted from a terminal Vout of the amplifier OP2.
| JPS5896414 | HIGH ORDER GENERAL-PURPOSE SWITCHED CAPACITOR FILTER |
| JPS6459533 | SWITCHED CAPACITOR ADDER |
| JPS6028319 | FILTER CIRCUIT |
KOMAZAKI TOMOKAZU
GUNJI KATSUHIKO
