FREQUENCY AUTOMATIC REGULATION CIRCUIT OF GMC FILTER, GM AUTOMATIC REGULATION CIRCUIT OF MUTUAL CONDUCTANCE AMPLIFIER AND ITS MOS INTEGRATED CIRCUIT

摘要

PROBLEM TO BE SOLVED: To automatically regulate gm of a gmC filter to realize a filter with high frequency precision. SOLUTION: A frequency automatic regulation circuit 11 consists of MOS transistors Q31, Q32, MOS transistors Q33, Q34 connected between a power source Vdd and Q31, Q32, a switched capacitor circuit 13 connected with a source of Q31 and a transistor Q42 connected with the other end of the switched capacitor circuit 13 and a source of the MOS transistor Q32, etc. and control voltage VGM is provided to a gate of Q42. gm is automatically regulated to a fixed value by supplying the control voltage VGM to a current source of a mutual conductance amplifier. COPYRIGHT: (C)2006,JPO&NCIPI