Data Sheet

AD633

Rev. K | Page 13 of 20

MODEL RESULTS

Circuit simulation using SPICE models embedded in various

application formats such as PSPICE, Multisim, and SIMetrix is a

popular and efficient method of assessing the integrity of a

circuit before creating the printed circuit board in which the

circuits are ultimately used. Although impossible to

demonstrate all of the multiplier functions in every available

program, Figure 24 through Figure 41 demonstrate how the

schematic and graph for simple dc, sin(x), and pulse

applications appear in three popular SPICE programs. If a

simulator is not shown here, a good way to progress is to start

with a basic dc circuit to verify that the circuit converges and

then continue with waveforms that are more complex. When

analyzing nonlinear devices such as multipliers, the most

common simulation issue is convergence, the iterative process

by which SPICE seeks the initial dc bias condition before

completely solving the circuit and displaying a graph.

Figure 24 through Figure 41 are arranged schematic first,

followed by the graphic result. If the user has a problem with a

simulator, the most efficient fix is to contact applications

support for the program in use.

EXAMPLES OF DC, SIN, AND PULSE SOLUTIONS

USING MULTISIM

Figure 24. Circuit to Multiply Two Integers Schematic Created in Multisim

Figure 25. Circuit to Multiply Two Integers Response Graph Displayed in Multisim

(2 V × 4 V)/10 V = 0.8 V

Figure 26. Frequency Doubler Circuit Schematic Created in Multisim

Figure 27. Frequency Doubler Response Graph Displayed in Multisim

Figure 28. Pulse Circuit Schematic Created in Multisim

Figure 29. Pulse Circuit Response Graph Displayed in Multisim