Hybrid scanner for use in an improved MDA tester
US5861743A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 1995 |
| Grant date | Jan 19, 1999 |
| Priority date | — |
| Expiry date | Dec 21, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/3004
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A hybrid scanner for switching internal analog buses to system pin channels. Semiconductor switches switch most scanner buses to system pin channels, but mechanical relays perform switching for at least one bus used for high-current test signals. To perform low-impedance guarding and/or high-current backdriving, the low impedance, high current bus is typically connectable to one or more overdriver circuits and a guard voltage potential through mechanical relays. The scanner is capable of supporting in-circuit tests covering the most significant regions of the fault spectrum can be made more reliable and much smaller and less costly than the scanners conventionally used in traditional broad spectrum testers. It turns out that this test-supporting capability can be achieved by adding only a few mechanical relays to an otherwise semiconductor-switch-based scanner. Only those necessary to support low-impedance and high-current test operations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.