Patent · US Expired

Universal serial bus transmitter

US7500033B2 · kind B2 · utility

4Cited by
4References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 6, 2005
Grant dateMar 3, 2009
Priority date
Expiry dateDec 11, 2025

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F13/4072
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A Universal Serial Bus transmitter comprising a USBTXP input and a USBTXM input for receiving respective data signals, and a USBP driver and a USBM driver for applying the respective data signals to USBP and USBM wires respectively. The transmitter comprises a transmit signal generator responsive to an asserting edge of a signal at one of the USBP and USBM inputs to define a leading edge of a transmit signal (USBTXIP) and to a corresponding de-asserting edge of a signal at the other of the USBP and USBM inputs to define the subsequent trailing edge of said transmit signal (USBTXIP). Even if the duty cycles of the input signals USBTXP and USBTXM are substantially different from 50%, this does not cause unacceptable jitter of successive crossover points nor cause the crossover point voltage level to be outside the USB tolerance, centred on 50% of the voltage swings of the USBP and USBM signals.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.