Page 177 - Op Amps Design, Applications, and Troubleshooting

160 VOLTAGE COMPARATORS

Appendix 6 shows the characteristics for a 1N914A diode. Almost any diode will
satisfy our modest requirements. The 1N914A is a standard, low-cost diode that
we can use for this application.
This completes the design of the window detector circuit. The final schematic
is shown in Figure 3.15. Figure 3.16 shows the actual waveforms produced by the
circuit. Table 3.3 compares the original design goals with the measured circuit per-
formance.

FIGURE 3.15 A window detector
designed for a lower limit of +7.5 volts
and an upper limit of +10 volts

FIGURE 3.16 Oscilloscope displays showing the performance of the circuit in Figure 3.15. (Test
equipment courtesy of Hewlett-Packard Company.)