During the last decade commercial software packages for circuit design matured concurrent with PC operating systems. Although optimized for general-purpose design, when used imaginatively, they are useful for circuits that employ piezoelectric devices. This paper illustrates CAD for such circuits with simple examples as the vehicle. The GENESYS 7 suite from Eagleware Corporation is used but the techniques are applicable to other CAD tools. A 4-section bulk-quartz resonator 9 MHz ladder bandpass filter and a SAW resonator 900 MHz oscillator are used to illustrate a few selected CAD techniques for circuits with piezoelectric devices including: (1) Synthesis (2) Equation defined parameters (3) Component influences (4) Standard values (5) Component tolerances (6) Resonator cross coupling (7) Oscillator design methodology (8) Oscillator loaded Q (9) Device current (10) Optimization (11) Load pulling
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