Output buffer drive circuit with initial drive for semiconductor devices
US6411120B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 1, 2000 |
| Grant date | Jun 25, 2002 |
| Priority date | — |
| Expiry date | May 1, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/163
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Output drivers do not generate current when the pull up and pull down circuits are producing control signals which are below the turn on thresholds. Accordingly, no noise is translated to the output of the device in this period of time. Accordingly, an initial drive interval is provided in which the pull up and pull down control signals are driven with higher current so that the corresponding signal changes at a higher rate of speed before it reaches the turn on thresholds. Near the turn on thresholds, the rate of change of the pull up and pull down control signals is controlled to minimize noise during the transition and thereafter. A tristate output driver with a pull up signal and pull down signal pre-driver circuit uses a method for producing a pull up signal which includes causing a transition of the pull up signal from a starting level of the pull up signal to near the pull up threshold at a first rate of change, and a driving the pull up signal to an ending level beyond the pull up threshold at a second rate of change which is slower than the first-rate change. In a similar fashion, the method includes causing a transition of the pull down signal from a starting level of the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.