Novatek Microelectronics Corp.

Dean Jau

Edward Tsai

Chiao-Yen Tai

Roger Chen

Jeff Hsin

A universal serial bus (USB) transmission system for transmitting a monitor control signal and a data signal from a monitor system to a main frame is provided. The universal serial bus transmission system separately includes a universal serial bus interface IC and a monitor controller IC between which the monitor control signal and the data signal are transmitted through a low-speed transmission interface, thereby reducing costs for handling electromagnetic interference (EMI). Furthermore, the universal serial bus interface can be modularized to allow the monitor system to serve as a general monitor system or a USB monitor system, thereby increasing the utility of the monitor system.

Method for reducing electromagnetic interference (EMI) in a universal serial bus transmission system

An electromagnetic safety (EMS) enhancement circuit is provided for a USB (Universal Serial Bus) system, which can simulate an unplugging and replugging action so as to ensure continuous operation of the USB device after being disconnected from the USB interface due to electromagnetic interferences. The EMS enhancement circuit utilizes an EMS detection unit to detect the EMS condition of the data communication between the USB device and the USB interface; if abnormal, the EMS detection unit will output an overflow signal to a resume-control unit. The resume-control unit can output a pull-up control signal to a voltage pull-up circuit so as to control the voltage pull-up circuit in such a manner that, when the USB device is disconnected from the USB interface, the voltage pull-up circuit is first inhibited from outputting a voltage signal to one data line of the USB interface to thereby simulate an unplugging action and, after a preset time, be enabled again to output the voltage signal to thereby simulate a replugging action. The simulated unplugging and replugging action can then automatically reconnect the USB device to the USB interface for continuous operation of the USB device.

Growing community of inventors

Miao-Li Hsien, Taiwan

Dean Jau