Electronics devices manufactured today are often required to survive a discharge of 8kV contact discharge i. While this is the aim, not all devices will survive this and in many cases the discharge may be greater than this. It is therefore wise to add additional protection. This may be achieved using a circuit that clamps the maximum voltages to just outside the maximum operating extremes.
Typically this may be just above the rail voltage and just below the zero volt line. A typical circuit that can be used for clamping voltages employs reverse biased diodes from the input line to the voltage rail and to ground.
Snapback and the ideal ESD protection solution (Electrostatic Discharge)
This ESD protection circuit must ensure that the voltage excursions on the input line are limited. The operation of the circuit is very simple in that the diodes, D1 and D2 are reverse biased under normal operating conditions. However if a pulse occurs that raises the input voltage above the rail voltage the top diode, D1, will conduct. Similarly if the voltage falls below the ground voltage, the other diode, D2, will conduct.
Types of ESD
However this is not always the case as seen below. The typical response curve for an electrostatic discharge is defined by IEC and it simulates a typical electrostatic discharge curve. The waveform has a rise time of about 1 ns and the current level peaks at 30A. To suppress these voltages, very effective clamping circuits are required and ESD design guidelines need to specify acceptable components and performance limits. To provide an approximation to the clamping voltage of a diode the clamping voltage can be approximated as follows:. It can be seen that the clamping voltage is related to both the conduction or breakdown voltage dependent upon the type of diode used and also the dynamic resistance of the diode.
With the very high instantaneous currents exhibited by electrostatic discharges, even very low values of inductance will mean the dynamic resistance is high enough to mean that excessive voltages will appear on the interface lines.
Don’t Get Zapped! What to Know About ESD
Even with DC clamp voltages of around 5V and fast switching diodes, voltages appearing on the device terminals from an electrostatic discharge may exceed V. The clamp circuit will have limited the discharge but not to the extent anticipated. In many cases this will be sufficient because of the short duration of the pulses, and the circuits may survive.
- What is Electrostatic Discharge?.
- ggNMOS - Wikipedia?
- Weaving The Food Web Community Food Security in California;
- ESD protection requirement?
- I Think Im In Love With You.
- Philosophy of Language: The Central Topics!
It is therefore necessary to optimise the circuit to provide the required level of protection. Hardcover , pages.
- ESD Protection Device and Circuit Design for Advanced CMOS Technologies.
- ESD Design Guidelines: for electronic circuits.
- Product details.
More Details Original Title. Other Editions Friend Reviews.
See a Problem?
To see what your friends thought of this book, please sign up. To ask other readers questions about ESD , please sign up. Lists with This Book.
- Download Product Flyer.
- ESD: Circuits and Devices - PDF Free Download?
- Chase the Moon (Harper Romance).
- Low-C ESD Protection Design in CMOS Technology.
This book is not yet featured on Listopia. Community Reviews.
Showing Rating details. All Languages. More filters.
Sort order. Keivan rated it really liked it Jan 21, Steve B marked it as to-read Apr 29, WakamoSya marked it as to-read May 30, Yu Li added it Jun 18, There are no discussion topics on this book yet.