A CMOS Current-Mode Band-Pass Filter Using Q-Enhancement Technique

Yuhki MARUYAMA  Akira HYOGO  Keitaro SEKINE  

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E86-A   No.2   pp.414-418
Publication Date: 2003/02/01
Online ISSN: 
Print ISSN: 0916-8508
Type of Manuscript: Special Section LETTER (Special Section on Analog Circuit Techniques and Related Topics)
filter,  CMOS,  current-mode,  Q-enhancement,  area efficiency,  

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A CMOS current-mode continuous-time band-pass filter using the positive feedback Q (quality factor) - enhancement technique is presented in this paper. Q of the proposed filter can be mainly determined by the ratio of the two MOSFETs' transconductances in a Q-setting part, not by the ratio of two capacitance values similar to most of conventional band-pass filters. This filter can realize high Q value in spite of small chip area. Therefore, when higher value of Q is needed, the proposed filter does not need large capacitor which occupies large area on an IC chip. The proposed filter spends smaller chip area than the conventional one under the condition of Q>2. The proposed circuit is simulated by Spectre to confirm its characteristics.