Design and applications of a family of optoelectronic photocurrent logical elements on the basis of current mirror and comparators

摘要

We consider design of hardware realizations of optoelectronic logical elements of two-valued logic with current inputs and current outputs on the basis of CMOS current mirrors and circuits which realize the limited difference functions. We show advantages of such elements consisting in encoding of Boolean variables by the photocurrent levels, that allows easily to provide optical inputs (by photodetectors) and optical outputs (by light-emitting devices). The conception of construction of the family of the offered optoelectronic photocurrent logical elements (OPLE) consists in the use of a few current mirrors realized on 1.5 μm technology CMOS transistors. Presence of four - ten transistors, one - two photodetectors makes the offered circuits quite compact and allows their integration in 1D and 2D arrays. In the presentation we consider the whole family of the offered circuits, show the simulation results and possible prospects of application of the circuits in particular for time-pulse coding for multivalued, continuous, neuro-fuzzy and matrix logics. The simulation results of the NOT, AND, OR, OR-NOT current logical elements on the 1.5 μm technology CMOS transistors showed that the level of logical unit can change from 1 uA to 10 uA for low-power consumption variants and from 10uA to 100uA for high-speed variants. Signals delays, values of fronts and cutoffs at operation with impulse logical signals with 1uA logical unit are not exceed 70-140ns and at operation with impulse logical signals with 100uA logical unit are no more than 4-6ns and the consumption power is 200-400uW.