Circuitry and method for duty measurement
US6549571B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | May 11, 1999 |
| Grant date | Apr 15, 2003 |
| Priority date | — |
| Expiry date | May 11, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/0337
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Duty measuring circuitry of the present invention includes a pulse detecting circuit for detecting at least one of a convex pulse width and a concave pulse width included in an input data signal. A duty decision circuit determines whether or not the convex pulse width or the concave pulse width detected is smaller than a preselected value. If the detected pulse width is smaller than the preselected, the duty decision circuit determines that the pulse width is valid, and feeds it to an averaging circuit. The circuitry obviates the need for an exclusive fixed pattern, e.g., ONEs and ZEROs alternating with each other customarily used for the measurement of a duty. In addition, the circuitry is capable of accurately measuring a duty even with a random pattern based on RZ (Return-to-Zero) code or NRZ (Non-Return-to-Zero) code.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.