| 摘要 |
PURPOSE:To establish the filter of simple constitution and low cost, by providing the CCd filter having a plurality bits and the input section providing the high specific resistivity film resistor having a given resistance value depending on the coefficient. CONSTITUTION:When an input signal is fed between the terminals SG1 and SG2, the taps Ai, Bi and Ai' and Bi' of the polycrystal silicon resistors R1 to Rn and R1' to Rn' are fed with the voltages ei and ei' proportional to the resistance value for between the gates G1 and G2 and G1' and G2'. Depletion layer is formed between the gate electrodes and charge is flowed to the depletion layer with the voltage fed to the source S. When the high level voltage is fed to the transfer electrode T10 of MCCD integrators 10 and 11, the charge is flowed to the MCCD integrators and is transferred to the output side while being meandered toward arrow with the transfer mode voltage fed to the electrode T1o. The differential amplifier AMP amplifies the difference of the output of MCCD 10 and 10'. This is the input coefficient type filter weighted with the resistors R1 and R1' for the input signal. Since highly accurate polycrystal silicon resistors can easily obtained, the filter can be made with low cost. |
