Monday, January 2, 2017

Electrostatic Discharge(ESD) Analysis

What is ESD?
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.An Electrostatic Discharge (ESD) strike is a constant threat to device reliability and functionality. Many low-voltage core chips or system ASICs only offer device-level Human-Body Model (HBM) ESD device protection, which doesn’t address the risks of system-level ESD strikes.ESD can occur when an electronic device comes near the human body or when it’s around another device (machine interface contact). A prime example involves connecting together two devices, such as plugging a mobile phone into a laptop. The person’s hand may touch the connecting pins, or if the device is charged up, ESD may occur when mating the connectors.
ESD Damage
•Burn Out
•Breakdown of insulator
•Decrease of lifetime
•Software Failure
ESD Protection of an Smart Phone Circuit
Electrostatic discharge (ESD) looms as one of the biggest threats to a mobile phone’s sensitive components. ESD is a sudden high voltage spike caused by charged objects touching, or in close proximity to, each other. Since these voltage spikes typically produce thousands of volts, they may damage sensitive components (e.g., ICs) in the system
  • The IEC61000-4-2standard defines standard test conditions that electronic equipment should withstand. It assumes that the user will take no precautions to prevent any ESD damage, and it defines a variety of levels that the equipment should withstand.
  • The typical curve for an electrostatic discharge defined by IEC61000-4-2has a rise time of about 1 ns and a peak current level of around 30A.
ESD Analysis

Static charge is an unbalanced electrical charge at rest. Typically, it is created by insulator surfaces rubbing together or pulling apart. One surface gains electrons, while the other surface loses electrons. This results in an unbalanced electrical condition known as static charge. When a static charge moves from one surface to another, it becomes ESD. ESD is a miniature lightning bolt of charge that moves between two surfaces that have different potentials. It can occur only when the voltage differential between the two surfaces is sufficiently high to break down the dielectric strength of the medium separating the two surfaces. When a static charge moves, it becomes a current that damages or destroys gate oxide, metallization, and junctions. ESD can occur in any one of four different ways: a charged body can touch an IC, a charged IC can touch a grounded surface, a charged machine can touch an IC, or an electrostatic field can induce a voltage across a dielectric sufficient to break it down.

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