US4646299A
Expired / Lapsed
US
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Method and apparatus for applying and monitoring programmed test signals during automated testing of electronic circuits
Assignee: Fairchild Semiconductor Corp
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Filing: 1984-05-17
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Granted: 1987-02-24
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Expires: 2004-05-17
Abstract
Abstract A plurality of test signal applying and monitoring circuits are coupled to pins of an electronic device being tested to force test stimuli signals onto input pins of the device under test. The response signals are monitored while the device is being tested. Each test signal applying and monitoring circuit includes a node to be coupled to a pin of the device under test, a digitally programmed source for supplying a test signal connectable to the node by a first switch, and a comparison circuit connected to the node by a second switch for indicating the relative amplitude of the response signal with respect to a programmed reference level. The digitally programmed source is included for providing gated voltage-current crossover forcing functions during functional testing to minimize the disturbance when the device being tested is connected and to protect out of tolerance devices. Programmable voltage and current values define a pass window to assure a non-ambiguous go/no-go result during testing. Other features are also disclosed.
Inventors
- 👤 John Schinabeck
- 👤 James R. Murdock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:24
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/28; G01R31/317; G01R31/3181; G01R31/319; G01R31/3193; G01R31/31937; G01R31/31712; G01R31/31713; G01R31/31903; G01R31/31908; G01R31/3191; G01R31/31917; G01R31/31922; G01R31/31928; G01R31/31935; H; H03; H03K; H03K5/00; H03K5/13; H03K5/131; H03K5/14; G01R31/31926; H03K2005/00013; H03K2005/0015; H03K2005/00234; H03K2005/00247; H03K2005/00254; H03K2005/0026
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
135 words
A method for applying and monitoring a test signal at a node of a device under test including digitally programmed source means having a preselected programmed voltage-current characteristic defined by not-to-exceed voltage rail and current rail levels switchably connected by a first switch means to the node for supplying a test signal to the node and comparison means switchably connected by a second switch means to the node, the method comprising the steps of: connecting the test signal to the node; comparing the test signal with a preselected programmed reference level; providing an indication of the relative magnitude of the test signal with respect to the preselected programmed reference level; and providing a preselected programmed constant signal in the event that the test signal has a predetermined relationship with respect to the programmed reference level.
Claim 2
Independent Claim
135 words
A method for applying and monitoring a test signal at a node of a device under test including digitally programmed source means having a preselected programmed voltage-current characteristic defined by not-to-exceed voltage rail and current rail levels switchably connected by a first switch means to the node for supplying a test signal to the node and comparison means switchably connected by a second switch means to the node, the method comprising the steps of: connecting the test signal to the node; comparing the test signal with a preselected programmed reference level; providing an indication of the relative magnitude of the test signal with respect to the preselected programmed reference level; and providing a preselected programmed constant signal in the event that the test signal has a predetermined relationship with respect to the programmed reference level.
Claim 3
Dependent Claim
30 words
The method of claim 1 wherein the test signal is a forcing function which starts at zero volts and one percent of the maximum current of a preselected voltage-current range.
Claim 4
Dependent Claim
127 words
The method of claim 1 wherein the step of comparing the test signal with a preselected programmed reference level comprises comparing the voltage applied to the node with the preselected programmed voltage rail level, the step of providing an indication of the relative magnitude of the test signal with respect to the preselected programmed reference level comprises providing an indication of the relative magnitude of the voltage applied to the node with respect to the voltage rail level, and the step of providing a preselected programmed constant signal in the event that the test signal has a predetermined relationship with respect to the preselected programmed reference level comprises applying the preselected programmed current rail level when the voltage applied to the node reaches the voltage rail level.
Claim 5
Dependent Claim
30 words
The method of claim 3 wherein the test signal is a forcing function which starts at zero volts and one percent of the maximum current of a preselected voltage-current range.
Claim 6
Dependent Claim
124 words
The method of claim 1 wherein the step of comparing the test signal with a preselected programmed reference level comprises comparing the current at the node with the preselected programmed current rail level, the step of providing an indication of the relative magnitude of the test signal with respect to the preselected programmed reference level comprises providing an indication of the relative magnitude of the current at the node with respect to the current rail level, and the step of providing a preselected programmed constant signal in the event that the test signal has a predetermined relationship with respect to the preselected programmed reference level comprises applying the preselected programmed voltage rail level when the current at the node reaches the current rail level.
Claim 7
Dependent Claim
30 words
The method of claim 5 wherein the test signal is a forcing function which starts at zero volts and one percent of the maximum current of a preselected voltage-current range.
Claim 8
Dependent Claim
160 words
Apparatus for applying and monitoring a test signal at a node of a device under test, comprising: digitally programmed source means switchably connected by a first switch means to the node, the digitally programmed source means having a preselected programmed voltage-current characteristic defined by not-to-exceed voltage rail and current rail levels for supplying test signals and alternatively a preselected programmed constant signal to the node; and comparison means connected to the digitally programmed source means and switchably connected by a second switch means to the node for indicating the relative magnitude of the test signal with respect to a preselected programmed reference level; the digitally programmed source means supplying the test signals unless the test signal applied has a predetermined relationship with respect to the preselected programmed reference level; the digitally programmed source means supplying the preselected programmed constant signal in the event that the applied test signal has a predetermined relationship with respect to the preselected programmed reference level.
Claim 9
Dependent Claim
160 words
Apparatus for applying and monitoring a test signal at a node of a device under test, comprising: digitally programmed source means switchably connected by a first switch means to the node, the digitally programmed source means having a preselected programmed voltage-current characteristic defined by not-to-exceed voltage rail and current rail levels for supplying test signals and alternatively a preselected programmed constant signal to the node; and comparison means connected to the digitally programmed source means and switchably connected by a second switch means to the node for indicating the relative magnitude of the test signal with respect to a preselected programmed reference level; the digitally programmed source means supplying the test signals unless the test signal applied has a predetermined relationship with respect to the preselected programmed reference level; the digitally programmed source means supplying the preselected programmed constant signal in the event that the applied test signal has a predetermined relationship with respect to the preselected programmed reference level.
Claim 10
Dependent Claim
44 words
Apparatus as in claim 7 wherein the digitally programmed source means is a crossover source which supplies a test signal in the form of a forcing function that starts at zero volts and one percent of the maximum current of a preselected voltage-current range.
Claim 11
Dependent Claim
90 words
Apparatus as in claim 7 wherein the comparison means compares the voltage applied to the node with the preselected programmed voltage rail level for providing an indication of the relative magnitude of the voltage applied to the node with respect to the voltage rail level; the digitally programmed source means supplying the test signals unless the voltage applied to the node reaches the voltage rail level; the digitally programmed source means supplying the preselected programmed current rail level when the voltage applied to the node reaches the voltage rail level.
Claim 12
Dependent Claim
44 words
Apparatus as in claim 9 wherein the digitally programmed source means is a crossover source which supplies a test signal in the form of a forcing function that starts at zero volts and one percent of the maximum current of a preselected voltage-current range.
Claim 13
Dependent Claim
86 words
Apparatus as in claim 7 wherein the comparison means compares the current at the node with the preselected programmed current rail level for providing an indication of the relative magnitude of the current at the node with respect to the current rail level; the digitally programmed source means supplying the test signals unless the current at the node reaches the current rail level; the digitally programmed source means supplying the preselected programmed voltage rail level when the current at the node reaches the current rail level.
Claim 14
Dependent Claim
44 words
Apparatus as in claim 11 wherein the digitally programmed source means is a crossover source which supplies a test signal in the form of a forcing function that starts at zero volts and one percent of the maximum current of a preselected voltage-current range.
Claim 15
Dependent Claim
15 words
Apparatus as in claim 7 wherein the switch means are controlled by a computer means.
Claim 16
Dependent Claim
12 words
Apparatus as in claim 13 wherein the switch means comprise reed relays.
Claim 17
Dependent Claim
14 words
Apparatus as in claim 14 wherein the computer means comprises a test head controller.
Claim 18
Dependent Claim
15 words
Apparatus as in claim 7 wherein the digitally programmed source means is a crossover source.
Claim 19
Dependent Claim
37 words
Apparatus as in claim 16 wherein the digitally programmed source means supplies a test signal which is a forcing function that starts at zero volts and one percent of the maximum current of a preselected voltage-current range.
Claim 20
Independent Claim
253 words
A method for monitoring the response signal at a node of a device under test caused by a test signal applied to the node by digitally programmed source means having a preselected programmed voltage-current characteristic defined by not-to-exceed voltage rail and current rail levels switchably connected by a first switch means to the node and comparison means switchably connected by a second switch means to the node, the method comprising the steps of: connecting the test signal to the node; comparing the response signal voltage at the node with a first preselected programmed voltage level; comparing the response signal voltage at the node with a second preselected programmed voltage level; comparing the response signal current at the node with a first preselected programmed current level; comparing the response signal current at the node with a second preselected programmed current level; providing an indication of the relative amplitude of the response signal voltage and current with respect to the first and second preselected programmed voltage levels and first and second preselected programmed current levels, respectively; providing a pass signal when the response signal voltage and current have a first predetermined relationship with respect to the first and second preselected programmed voltage levels and first and second preselected programmed current levels, respectively; and providing a fail signal when the response signal voltage and current have a second predetermined relationship with respect to the first and second preselected programmed voltage levels and first and second preselected programmed current levels, respectively; thereby providing a non-ambiguous pass/fail result.
Claim 21
Independent Claim
253 words
A method for monitoring the response signal at a node of a device under test caused by a test signal applied to the node by digitally programmed source means having a preselected programmed voltage-current characteristic defined by not-to-exceed voltage rail and current rail levels switchably connected by a first switch means to the node and comparison means switchably connected by a second switch means to the node, the method comprising the steps of: connecting the test signal to the node; comparing the response signal voltage at the node with a first preselected programmed voltage level; comparing the response signal voltage at the node with a second preselected programmed voltage level; comparing the response signal current at the node with a first preselected programmed current level; comparing the response signal current at the node with a second preselected programmed current level; providing an indication of the relative amplitude of the response signal voltage and current with respect to the first and second preselected programmed voltage levels and first and second preselected programmed current levels, respectively; providing a pass signal when the response signal voltage and current have a first predetermined relationship with respect to the first and second preselected programmed voltage levels and first and second preselected programmed current levels, respectively; and providing a fail signal when the response signal voltage and current have a second predetermined relationship with respect to the first and second preselected programmed voltage levels and first and second preselected programmed current levels, respectively; thereby providing a non-ambiguous pass/fail result.
Claim 22
Dependent Claim
30 words
The method of claim 18 wherein the test signal is a forcing function which starts at zero volts and one percent of the maximum current of a preselected voltage-current range.
Claim 23
Dependent Claim
299 words
Apparatus for monitoring the response signal at a node of a device under test caused by a test signal applied to the node, comprising: digitally programmed source means switchably connected by a first switch means to the node, the digitally programmed source means having a preselected programmed voltage-current characteristic defined by not-to-exceed voltage rail and current rail levels for supplying test signals to the node; first comparison means switchably connected by a second switch means to the node for indicating the relative amplitude of the response signal voltage at the node with respect to a first preselected programmed voltage level; second comparison means switchably connected by the second switch means to the node for indicating the relative amplitude of the response signal voltage at the node with respect to a second preselected programmed voltage level; third comparison means switchably connected by the second switch means to the node for indicating the relative amplitude of the response signal current at the node with respect to a first preselected programmed current level; fourth comparison means switchably connected by the second switch means to the node for indicating the relative amplitude of the response signal current at the node with respect to a second preselected programmed current level; means connected to the comparison means for providing a pass signal when the response signal voltage and current have a first predetermined relationship with respect to the first and second preselected programmed voltage levels and first and second preselected programmed current levels, respectively; and means connected to the comparison means for providing a fail signal when the response signal voltage and current have a second predetermined relationship with respect to the first and second preselected programmed voltage levels and first and second preselected programmed current levels, respectively; whereby a non-ambiguous pass/fail result is provided.
Claim 24
Dependent Claim
299 words
Apparatus for monitoring the response signal at a node of a device under test caused by a test signal applied to the node, comprising: digitally programmed source means switchably connected by a first switch means to the node, the digitally programmed source means having a preselected programmed voltage-current characteristic defined by not-to-exceed voltage rail and current rail levels for supplying test signals to the node; first comparison means switchably connected by a second switch means to the node for indicating the relative amplitude of the response signal voltage at the node with respect to a first preselected programmed voltage level; second comparison means switchably connected by the second switch means to the node for indicating the relative amplitude of the response signal voltage at the node with respect to a second preselected programmed voltage level; third comparison means switchably connected by the second switch means to the node for indicating the relative amplitude of the response signal current at the node with respect to a first preselected programmed current level; fourth comparison means switchably connected by the second switch means to the node for indicating the relative amplitude of the response signal current at the node with respect to a second preselected programmed current level; means connected to the comparison means for providing a pass signal when the response signal voltage and current have a first predetermined relationship with respect to the first and second preselected programmed voltage levels and first and second preselected programmed current levels, respectively; and means connected to the comparison means for providing a fail signal when the response signal voltage and current have a second predetermined relationship with respect to the first and second preselected programmed voltage levels and first and second preselected programmed current levels, respectively; whereby a non-ambiguous pass/fail result is provided.
Claim 25
Dependent Claim
44 words
Apparatus as in claim 20 wherein the digitally programmed source means is a crossover source which supplies a test signal in the form of a forcing function that starts at zero volts and one percent of the maximum current of a preselected voltage-current range.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-02-23 | 1990-08-25 | 1991-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-23 | 1994-08-25 | 1995-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-23 | 1998-08-25 | 1999-02-24 | $7700.00 | Window Closed / Lapsed |