An MTL-Based Configurable Block for Current-Mode Nonlinear Analog Computation

A configurable analog block (CAB) architecture based upon the MOS translinear (MTL) principle is proposed. It is programmed to implement some current-mode nonlinear analog computational functions. The proposed CAB architecture consists of one cascoded MTL cell, a local switch network, and a pMOS array. The cascoded MTL cell implements one MTL loop that is reconfigurable and programmable using the switch network and the pMOS array. This CAB architecture is capable of implementing various frequently used nonlinear functions, such as squaring/inverse function, rectifying (absolute value), and square-rooting/geometric mean functions. The CAB has been fabricated in a 0.5- μm CMOS technology and verifies the concept. High capability and flexibility of the proposed CAB makes it suitable for current-mode analog computational and signal processing applications.