Chapter 4 - Noise Identification

Abstract

This chapter elaborates the noise identification and elimination methods. Noise identification and elimination methods are extremely valuable for design, product, or test engineers at any level. Discontinuity of electrical charges is the primary problem related to noise. These charges constitute the noise, or unwanted signal, when carried as discrete pulses in a conductor. They become more consequential as they are multiplied by the amplification stages. It has been found that grounding, if done properly, can be the primary answer to noise problems. Single-point grounding has the advantage of being the simplest method of grounding, but it is not very effective for controlling noise. The amount of noise in a resistor depends mainly on the shape of the component and the type of material in its structure. The resistor lead is the source of inductance and makes the element vulnerable to picking up surrounding magnetic fields, and the inherent capacitance of any resistor is about 0.5 pF. Most devices are capable of generating flicker noise, which is directly dependent on current flow. The main source of this noise is contamination at the emitter/base layer of the crystal in transistors and diodes. In this chapter the popcorn noise and contact noise have also been described.