1 V compact class-AB CMOS log filters

The paper proposes new circuit design techniques to implement very low-power and compact CMOS log-domain filters. The new approach is based on low-voltage topologies and low-current class-AB operation, combined with strong circuit reductions. The paper includes all the required basic building blocks for the synthesis of arbitrary log filters, such as signal input splitting and compression, differential integration with common-mode feedback (CMFB) and output expansion. Also, a comparative filter design example at 1 V is given for a standard 0.35 /spl mu/m CMOS technology.

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