
Migrating Industrial DfM into IC Manufacturing 63
whether the IC contains operational ampliers, high-resistance input cir-
cuits, or interface devices etc. Implementation of protection devices depend
also on the limiting properties of diodes. Excessive interfering voltage at
the I/Os of the circuit (e.g., a double operational amplier) can prevent it
from functioning correctly. Because silicon or Schottky diodes have too
high forward voltage (V
f
= 0.7 V or 0.4 V, respectively) and germanium
diodes, while more suitable (V
f
= 0.3 V), have a low operating tempera-
ture (T
max
= 90°C), the current limiting should be ...