Subject :- VLSI Design

Topic :- MOSFET Inverters

Difficulty :- High

ESD protection concepts have to guarantee the required ESD hardness considering possible stress paths between every two pins of a circuit. It was found that all commonly used protection circuit concepts cause a circuit stress for a part of the relevant stress combinations. In these cases, the discharge is not shunted effectively by the protection circuits.

Over voltages appear at output and input transistors, parasitic elements or internal circuit parts. The last effect was found to be caused by forward biased diode structures which divert the discharge current to the supply lines. To avoid stress or damage of the circuit, each path between inputs/outputs and supply lines has to be protected effectively. A new type of protection concept is presented which prevents circuit stress.

It is important to observe some basic steps to protect your computer hardware from potential damage caused by Electro Static Discharge or ESD.

ESD is created when the electrical field surrounding different objects varies and becomes balanced. The spark that is created when contact balances the fields can cause damage to electronic components. Protecting electronic components, like the hardware in your computer, is an easy task if components are properly handled and basic precautions are used.

There are a number of items available on the market to reduce the likelihood of ESD, among those items are: ESD wrist strap, shoe sole grounder, and conductive shoes. It is recommended you properly ground yourself before contacting any computer components.

Here are some basic steps you can take to reduce the chance of causing ESD.

1. Check the humidity. Relative humidity above 40% actually reduces the resistance of items that could generate a charge making it more difficult to generate an ESD. Note that very high humidity (80% or more) could cause other types of issues like corrosion.

2. Provide a common ground for your electronic components. Any charge that might build up would be discharged safely through that common ground. ESD grounding straps that connect to the computer chassis make great common grounds.

3. Wear protective devices like wrist straps, sole grounders, and/or conductive shoes. These items help to prevent electrostatic charge from building.

4. Keep your components in the anti-static bag until you are ready to install them. These bags are designed to prevent a charge from building.

5. Be sure to ground yourself to the computer case by contact ensuring your personal static charge has been discharged before you work on the inside of your computer.

These basic steps can help you avoid damage to your sensitive electronic components by preventing ESD.