Signal Diodes

Contents

Overview

Signal diodes (a.k.a. small signal diodes) are designed for rectification of low power signals rather than the higher power electronics that general purpose diodes are designed to rectify. Although they can’t handle high currents or high reverse voltages, they benefit from being able switch faster and therefore more suitable for higher frequency operation. Signal diodes are built in two different ways:

• Point contact diode
• Glass passivated diode

SPICE model for the small signal 1N4148 diode:

.model 1N4148 D 
+ IS = 4.352E-9 
+ N = 1.906 
+ BV = 110 
+ IBV = 0.0001 
+ RS = 0.6458 
+ CJO = 7.048E-13 
+ VJ = 0.869 
+ M = 0.03 
+ FC = 0.5 
+ TT = 3.48E-9