BB5 EMI / ESD FILTER IC’S CONFIGURATION AND MODIFICATION WITH TROUBLESHOOTING PROCEDURES….
What is EMI/ESD Filter?
This Filter where designed by Mobile Phones Engineers to protect the following hazardous elements in Electronic circuits...
Electromagnetic interference (or
EMI, also called
radio frequency interference or
RFI) is a disturbance that affects an electrical circuit due to either electromagnetic conduction or
electromagnetic radiation emitted from an external source.
[1] The disturbance may interrupt, obstruct, or otherwise degrade or limit the effective performance of the circuit. The source may be any object, artificial or natural, that carries rapidly changing electrical currents, such as an
electrical circuit, the
Sun or the
Northern Lights.
EMI can be intentionally used for
radio jamming, as in some forms of
electronic warfare, or can occur unintentionally, as a result of
spurious emissions for example through
intermodulation products, and the like. It frequently affects the reception of
AM radio in urban areas. It can also affect
cell phone,
FM radio and
television reception, although to a lesser extent.
Electrostatic discharge (
ESD) is the sudden and momentary
electric current that flows between two objects at different
electrical potentials caused by direct contact or induced by an
electrostatic field.
[1] The term is usually used in the
electronics and other industries to describe momentary unwanted currents that may cause damage to electronic equipment.
ESD is a serious issue in solid state
electronics, such as
integrated circuits. Integrated circuits are made from
semiconductor materials such as
silicon and insulating materials such as silicon dioxide. Either of these materials can suffer permanent damage when subjected to high voltages, as a result there are now a number of
antistatic devices that help prevent static build up. (quote in wikipidia)
Here is a list of codes on EMI/ESD filter in every Nokia Circuits...
Linear Mode
