Threshold Realization of Arithmetic Circuits

uout t What is the effect if R is not made and maintained exactly equal to Ri? If R is larger a in L-COMPARATOR U out ItCES TO than Ri then the circuit exhibits customary LL| UH UI H\ e+9x>C_~ \ 4°/ > transition occurs for uip>uo, and alternately au s iY~08 w . the UH->UL transition for ui,,uo [Fig. 6(c)]. Since the ideal Fig. 1-Ideal comparator characteristic. condition [Fig. 6(b)] is embraced by these Fig. 5-Composite characteristic (simplified) of a tunneltwo cases, it can be attained exactly in princidiode pair whose diodes have electrical characteristics ple. In practice, a minute amount of hysteresis similar to those shown in Fig. 3. is, of course, inevitable. ;R For high-speed operation, freedom from hysteresis will depend on diode junction ca-