Leadless devices for EMI suppression

Electromagnetic interference by unwanted signals/noise, electrostatic disch arge, electromagnetic induction, thunder lightening etc. has come in to foc us in recent years due to malfunctioning of sophisticated control, test, me asurement and host of other systems resulting in serious consequences. The drive;towards miniaturization and lower power consumption in portable elect ronic equipment is driving towards lower driving voltage. Interference from sources such as static electricity discharge from human body and other sou rces therefore has become a serious problem to modern equipment. Electronic equipment is therefore enclosed in specially conducting enclosures. Specia l components are used to protect the equipment from unwanted electro-magnet ic noise etc. Traditionally these surge and EMI suppression components were leaded type as they were easily accommodated in large size equipment's. Cu rrently leadless EMI and surge suppression components are essential to mini aturization of modern portable electronic equipment and for ensuring their reliability and efficient working in such hostile electromagnetic environme nt. The present paper gives a very brief of the essential devices, which ha ve been developed in recent years in the leadless format suitable for incor poration in portable electronic products. The components include surge supp ression devices (Gas discharge tubes, metal oxide varistor, zener diodes), and noise suppressing/filtering components based on soft ferrite, capacitor s (Plastic film, Multi-layer ceramic and Tantalum electrolytic) and other c omposite devices.