Built-in AC self test using pulse generators
US6466520B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 5, 1999 |
| Grant date | Oct 15, 2002 |
| Priority date | — |
| Expiry date | Feb 5, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/318516
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A circuit measures the signal propagation delay through a selected test circuit. The test circuit is provided with a feedback path so that the test circuit and feedback path together form a free-running oscillator. The oscillator then automatically provides its own test signal that includes alternating rising and falling signal transitions on the test-circuit input node. A phase discriminator samples the output of the oscillator and accumulates data representing the signal propagation delay of either rising or falling signal transitions propagating through the test circuit. The worst-case delay associated with the test circuit can then be expressed as the longer of the two. Knowing the precise worst-case delay allows IC designers to minimize the guard band and consequently guarantee higher speed performance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.