TABLE OF CONTENTS Robert Pease
Although transistors both bipolars and MOSFETs are immune to many problems, you can still have transistor troubles. Robust design methods and proper assumptions regarding their performance characteristics will steer you past the shoals of transistor vexation and the rocks of transistor disasters.
Transistors are wonderful they're so powerful and versatile. With a handful of transistors, you can build almost any kind of high-performance circuit: a fast op-amp, a video buffer, or a unique logic circuit.
On the other hand, transistors are uniquely adept at causing trouble. For example, a simple amplifier probably won't survive if you short the input to the power supplies or the output to ground. Fortunately, most op-amps include forgiving features, so that they can survive these conditions. When the mA741 and the LM101 op-amps were designed, they included extra transistors to ensure that their inputs and outputs would survive such abuse. But an individual transistor is vulnerable to damage by excessive forward or reverse current at its input, and almost every transistor is capable of melting. So it's up to us, the engineers, to design transistor circuits so that the transistors do not blow up, and we must troubleshoot these circuits when and if they do.
A simple and sometimes not-so-obvious problem is installing a transistor incorrectly. Because transistors have three terminals, the possibility of a wrong connection is considerably greater than with a mere diode. Small-signal transistors are often installed so close to a printed-circuit board that you can't see if the leads are crossed...
