Pull-up circuit
US7583105B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 29, 2004 |
| Grant date | Sep 1, 2009 |
| Priority date | — |
| Expiry date | Jul 1, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/01721
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A pull-up circuit comprises an operational amplifier which forms part of a feedback circuit, acting to bring a pull-up circuit output equal to a reference voltage input. The pull-up circuit may form part of a USB transceiver for incorporation in a USB Device. When the supply voltage of the USB Device is sufficiently high, it is used to provide the required pull-up voltage, with the feedback circuit including the operational amplifier the USB Device is not high enough to provide the required pull-up voltage. In that case, the USB bus voltage is used to generate the reference voltage which is used as an input to the feedback circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.