simplified word comparator

a delayed trigger pulse or an .external trigger input. None the less, the com- parator remains an almost indispens- able aid in the testing of digital circuits. The unit is based on two four-bit com- parators, ICi and IC2. The reference level for them can be set separately with switches S1...S 4 and S 5. . . S8 respectively. With these switches set as drawn, inputs A and B are intercon- nected: this is the don"t care position. With a switch set to its centre pos- ition, a high reference level is ob- tained, while when it is set tq the extreme right position, a low reference level is obtained. When all A and B inputs agree, the A=B output of IC2goes logic high. Gates N1... N14 suppress short spurious pulses that arise during the stabilization of the comparator inputs. The size of the binary word can be increased by cascading two or more comparators. Account must then be R3 R4 47k R5 R6 47k At 47k simplified word comparator Primarily intended as a trigger source for an oscilloscope ...