Electrostatic discharges and transient signals monitoring system and method

• US 6,563,319 B1
• Filed: 04/18/2000
• Issued: 05/13/2003
• Est. Priority Date: 04/19/1999
• Status: Active Grant

• Current Assignee: Desco Industries Incorporated
• Original Assignee: Credence Technologies, Inc. (3M Company)
• Inventors: Kraz, Vladimir
• Primary Examiner(s): Cuneo, Kamand
• Assistant Examiner(s): NGUYEN, TRUNG Q
• Application Number:
  US09/551,412
• Time in Patent Office: 1,120 Days
• Field of Search: 324/72, 324/72.5, 324/452, 324/765, 324/752, 324/454, 324/457, 324/455, 324/509, 324/510, 340/657, 340/670, 340/532, 340/649, 340/650, 340/652, 709/230, 361/212, 361/220, 356/417, 356/418
• US Class Current: 324/458
• CPC Class Codes: G01R 29/12 Measuring electrostatic fields or voltage-potential
• CPC Class Codes: G01R 31/1272 of cable, line or wire insulation, e.g. using partial discharge measurements locating faults in cables G01R31/083

Abstract

An ESD and transient signal monitoring system and method are provided wherein an ESD monitoring device may be used to continuously monitor ESD events and generate an indicating of the magnitude of the ESD events. A method for protecting an electronic device from ESD events is also described.

Claims

1. A device for detecting and measuring short pulse-type signals such as ESD Events and surges, comprising:

means for receiving a signal and converting the electromagnetic field into an electric signal;

resonance means that creates, from a short duration received electrical signal, a new secondary self-resonating signal with a longer duration having a magnitude that is a function of the magnitude of the received signal, wherein slower input signals will not create strong secondary resonance signals and will not be measured; and

signal measuring means for measuring the amplitude of the self-resonating signal in order to provide an analog or digital representation of the magnitude of the received filtered signal.

2. The device of claim 1 further comprising means for filtering the electric signal in order to reject signals with predetermined properties not associated with short transient-type signals and pass only signals with properties associated with short transient-type signals.

3. The device of claim 2, wherein the properties of said resonance means are tuned to the specific properties of measured events, i.e. machine-model (MM) discharge, human body discharge (HBM) or charged device model (CDM) that have different timing characteristics so that the maximum said secondary signal is generated when such selected type of event has occurred and on other type of events generates minimal said secondary signal.

4. The device of claim 2, wherein the output of said filtering means is connected to the input of a detecting means and the output of said detecting means is connected to the input of said signal measuring means so that said measuring means will measure direct current signal.

5. The device of claim 4, wherein the output of said detecting means is connected to the input of a threshold means and the output of said threshold means is connected to the input of a high-pass filter and the output of said high-pass filter is connected to the input of said signal measurement means so that said threshold means averages the level of background electromagnetic signal to establish the background threshold signal level and said high-pass filter rejects steady background signal levels and passes only rapidly-changing signals allowing measurements only of signals caused by short pulsed signals of interest that rise briefly above the background level.

6. The device of claim 5, wherein the threshold means is connected to second input of said measurement means where said measurement means thus ignores any received signal whose magnitude is below the one set by said threshold means.

7. The device of claim 6, wherein a control means of said threshold means is remotely located and provide threshold setting signal to said measurement means remotely.

8. The device of claim 6, wherein the output of said measurement means is connected to an event counter wherein each occurrence of event with the magnitude exceeding the level set by said threshold means is counted to provide a count of the number of relevant event occurrences.

9. The device of claim 1 further comprising a plurality of receiving means to provide information about the received signal from several locations.

10. The device of claim 1, wherein said signal measuring means comprises an analog-to-digital converter, a control means and a memory arrangement where every received signal is individually measured and recorded as it occurs and then the information of each event'"'"'s properties is communicated to the outside information recipient at a slower rate than incoming signals so that a slower-reacting recipient (i.e. data acquisition system) or a human eye can read this information.

11. The device of claims 10 further comprising an embedded web microserver connected to said control means and to information network thus providing information of each event via the internet.

12. The device of claim 11 wherein setting of threshold is available via Internet.

13. The device of claim 12 wherein said information network interface is established via wireless means.

14. The device of claim 1 further comprising a second receiving means coupled via a conductive means to said device and to a power source, the output of said second receiving means is connected to second detecting means and the output of second detecting means is connected to second input of said measurement means, wherein said measurement means contains comparison means for rejecting a signal from the first detecting means if it coincides with the input from the second detecting means in order to reject the signals that are most likely are carried on the wires and cables connected to said device rather than genuine signal of interest.

15. The device of claim 14, wherein said comparison means compares signals received from the first receiving means and the second receiving means by the properties of the signals in addition to the arrival time in order to reject the signals that coincide both in time of arrival and in their properties as most likely are carried on the wires and cables connected to said device rather than genuine signal of interest.

16. The device of claim 1 further comprising a processor for processing the received signal and outputting a calculated result.

17. A method for detecting and measuring short pulse-type signals such as ESD Events and surges, comprising:

receiving a signal and converting the electromagnetic field into an electric signal;

filtering the electric signal in order to reject signals with predetermined properties not associated with short transient-type signals and pass only signals with properties associated with short transient-type signals; and

measuring the signal to provide an analog or digital representation of the magnitude of the received filtered signal.

18. The method of claim 17, wherein said filtering comprises creating, from a short duration received signal, a new secondary self-resonating signal with a longer duration having a magnitude that is a function of the magnitude of the received signal, wherein slower input signals will not create strong secondary resonance signals and will not be measured.

19. The method of claim 17 further comprising detecting the output of the filtering wherein the output of said detecting is connected to the input of said signal measuring means so that said measuring means will measure direct current signal.

20. The method of claim 19 further comprising generating a threshold based on the detecting, high pass filtering the threshold, outputting the threshold to the signal measuring so that said threshold averages the level of background electromagnetic signal to establish the background threshold signal level and said high-pass filter rejects steady background signal levels and passes only rapidly-changing signals allowing measurements only of signals caused by short pulsed signals of interest that rise briefly above the background level.

21. The method of claim 20 further comprising counting the number of ESD events so that each occurrence of event with the magnitude exceeding the level set by said threshold means is counted to provide a count of the number of relevant event occurrences.

22. The method of claim 21 further comprising buffering the receiving signal so that the information about the received signal is passed to a recipient at a slower rate than incoming signals so that a slower-reacting recipient (i.e. data acquisition system) or a human eye can read this information.

23. The method of claim 17 further comprising processing the received signal and outputting a calculated result.

24. A device for detecting and measuring short pulse-type signals such as ESD Events and surges, comprising:

means for receiving a signal and converting the electromagnetic field into an electric signal;

means for filtering the electric signal in order to reject signals with predetermined properties not associated with short transient-type signals and pass only signals with properties associated with short transient-type signals

resonator for creating, from a short duration received signal, a new secondary self-resonating signal with a longer duration having a magnitude that is a function of the magnitude of the received signal, wherein slower input signals will not create strong secondary resonance signals and will not be measured; and

signal measuring means that provides an analog or digital representation of the magnitude of the received filtered signal.

25. A device for detecting and measuring short pulse-type signals, the device comprising:

an antenna;

a resonant circuit coupled with the antenna;

a detector having an input that is coupled with an output of the resonant circuit; and

a device for determining a property of a signal from the detector, the device being coupled with the detector.

26. The device of claim 25 wherein the detector is an integrated detector.

27. The device of claim 25, wherein the detector is a logarithmic detector.

28. The device of claim 25 wherein the detector is a primary detector circuit, further comprising a secondary detector circuit coupled with the output of said primary detector circuit and separating background emission from short transient signals, the secondary detector circuit including a subcircuit and a high-pass filter, the subcircuit making a signal at the output of the secondary detector circuit reflect the background electromagnetic emission level and the high-pass filter passing only sharp transient signals while rejecting a signal representing the background emission level.

29. The device of claim 28 further comprising:

an analog-to-digital converter, a first input of the analog-to-digital converter being coupled with an output of the operational amplifier and a second input to the analog-to-digital converter being coupled with a threshold voltage source;

a microprocessor coupled with the analog-to-digital converter;

an event-counter coupled with the microprocessor;

a reset switch coupled with the microprocessor;

an event notification circuit coupled with the microprocessor, the event notification circuit including at least one of a visual indication means and an audio indication means; and

a digital-to-analog converter coupled with the microprocessor.

30. The device of claim 28 wherein the subcircuit includes a diode, a capacitor and a resistor.

31. The device of claim 28 further comprising:

a comparator having a first input coupled with the output of the operational amplifier, a second input coupled with a threshold voltage control means, and a comparator output;

an event-counter coupled with the comparator output;

a reset switch coupled with the comparator output; and

an event notification circuit coupled with the microprocessor, the event notification circuit including at least one of a visual indication means and an audio indication means.

32. The device of claim 25 further comprising a peak-hold detector circuit for holding the detected peak voltage of a pulse for a sufficiently long duration to allow the measurement device to measure the pulse magnitude.

33. The device of claim 32 further comprising a memory coupled with the microprocessor.

34. The device of claim 25, wherein the antenna is a built-in antenna.

35. The device of claim 25, wherein the antenna is a remote antenna.

36. The device of claim 25, wherein the antenna includes a plurality of antennas connected to one base unit.

37. A device for detecting and measuring short pulse-type signals comprising:

an antenna; and

a resonant circuit coupled with the antenna, the resonant circuit receiving a first pulse-type signal from the antenna and producing a second signal having a property representative of a property of the first pulse-type signal such that the property of the first pulse-type signal is determinable based on the property of the second signal.

38. A device for detecting and measuring short pulse-type signals such as ESD Events and surges, comprising:

an antenna;

a resonant circuit coupled with the antenna;

a detector having an input that is coupled with an output of the resonant circuit; and

a measurement device coupled with the detector.