| 摘要 |
PURPOSE:To obtain a circuit suitable for IC, by constituting the primary low-pass filter with the circuit which supplies a current to the capacity element by the input signal, the circuit which absorbs the current from the capacity element, and the circuit which supplies a voltage to the capacity element. CONSTITUTION:Current supply circuit H1 and current absorbing circuit H2 are connected to terminal a1 of capacity circuit 21. Circuit H1 is controlled by input signal S1 to supply current I1 to element 21. Circuit H2 absorbs current I2 from element 21 by the control of the second signal S2 having the polarity opposite to signal S1. Voltage generating circuit G is connected to the other terminal a2 of element 21. Circuit G generates voltage V1 by signal S1 and generates voltage V2 of the opposite polarity by signal S2 and supplies them to element 21 through terminal a2 and outputs output signal SO from terminal TO. Signals S1 and S2 are given at different times; and if absolute values of currents I1 and I2 and voltages V1 and V2 are made equal to each other respectively, the capacity of element 21 is small, and it is constituted with an integrated circuit. |
