Browse Prior Art Database

ESD Monitor

IP.com Disclosure Number: IPCOM000089273D
Original Publication Date: 1977-Oct-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Dietrich, K: AUTHOR [+5]

Abstract

Computing systems may be sensitive to transient external electromagnetic phenomena whose magnitude is such that they lead to system errors. Such transients which are propagated on the power line may be generated by electrostatically charged operators touching the machine frame or by electrostatically charged furniture, such as a trolley, being brought into contact with the frame.

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ESD Monitor

Computing systems may be sensitive to transient external electromagnetic phenomena whose magnitude is such that they lead to system errors. Such transients which are propagated on the power line may be generated by electrostatically charged operators touching the machine frame or by electrostatically charged furniture, such as a trolley, being brought into contact with the frame.

This electrostatic discharge (ESD) monitor detects the transients and records their magnitude. A current probe feeds the transient signal to a special input circuit transforming the short-term high-amplitude current surge into a current- time integral signal having the form of an oscillating wave whose first positive peak amplitude is measured. Thus transient detection is independent of the polarity of the surge.

The positive peak amplitude is measured by a series of comparators fed by gradually downstepped voltage values from a reference voltage source. The comparison signals are stored in a series of latches and buffers which are periodically scanned and reset by the computing system. Thus an internal machine error can be correlated to an external discharge transient.

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