Patent · US Expired

Clock generator, particularly for USB devices

US6762635B2 · kind B2 · utility

8Cited by

3References

21Claims

0Family size

Assignee

Infineon Technologies AG · DE

Inventors

Michael Bruhnke · Munich, DE
Viktor Preis · Taufkirchen, DE
Uwe Weder · Freiburg im Breisgau, DE

Key dates

Filing date	Feb 25, 2003
Grant date	Jul 13, 2004
Priority date	—
Expiry date	Feb 25, 2023

Classification

Technology area (CPC G)Physics
CPC primaryG06F1/04
WIPO fieldBasic communication processes
WIPO sectorElectrical engineering

Abstract

In accordance with the USB specifications, an accuracy of 0.25% is required for the data transmission rate. To generate a clock signal that allows this accuracy, the invention uses a clock generator unit that does not require a crystal. The clock generator unit includes an internal clock generator, a pulse counter that is connected to the internal clock generator, a pulse number memory, and a pulse filter. The pulse counter counts the number of internally generated clock pulses between two pulses of the synchronization signal, which are transmitted in accordance with the USB specification. The difference between the ascertained pulse number and a nominal pulse number is evaluated and is used for controlling the pulse-suppressing pulse filter. This results in a stabilized clock signal.

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