Circuit-board tester with backdrive-based burst timing
US6175230A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 1999 |
| Grant date | Jan 16, 2001 |
| Priority date | — |
| Expiry date | Jan 14, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/3193
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Pin-driver circuitry in each of an automatic circuit tester (10)'s digital driver/sensor circuits (36) includes a current sensor (R.sub.sense, QS1, QS2, D1, and D2) and comparison circuit (58) that indicate whether the load current supplied by the driver exceeds a level set by a threshold input (CURRENT_VALUE). The pin-driver circuitry also includes a timer (60) whose output indicates whether the comparison circuit's output has been asserted for a length of time that exceeds a limit set by a duration input (TIME_VALUE). When it has, the tester disables the driver and thereby prevents damage that could otherwise result from excessive backdrive durations that the test-generation process did not anticipate. When no backdriving is sensed during a given burst of test signals, the tester forgoes the normal cool-down delay, thereby speeding the test process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.