A Current Mode Implementation of Shunting

In this paper we present a current-mode VLSI implementation of shunting inhibition. Our approach uses translinear circuit design techniques using MOS transistors operating in the subthreshold region. Compared to previous implementations our design achieves a larger dynamic range and also clearly demonstrates the dependence of the spatio-temporal response of the network on the input light mean-intensity. A 64-cell one-dimensional array of the SI circuit has been implemented and fabricated in a 2 CMOS process. Hspice simulation results as well as test results obtained from the chip are presented and discussed.