USB interface controller chip

• US 20030135673A1
• Filed: 01/03/2003
• Published: 07/17/2003
• Est. Priority Date: 01/16/2002
• Status: Active Grant

• Current Assignee: Elan Microelectronics Corporation
• Original Assignee: Elan Microelectronics Corporation
• Inventors: Chiu, Yen-Chang, Yeh, Ting-Hao, Lo, Ming-Chuan, Wu, Kao-Pin
• Granted Patent: US 6,915,419 B2
• Time in Patent Office: Days
• US Class Current: 710/72
• CPC Class Codes: G06F 13/4081 Live connection to bus, e.g. hot-plugging current or voltage limitation during live insertion H02H9/004

Abstract

A USB interface controller chip comprises a pair of signal ports for being connecting with a pair of USB signals and a power node for being connecting with a supply voltage characterized in that the controller chip is built-in with a pull-up resistor connected between the power node and one of the pair of signal ports, and the pull-up resistor has a resistance consistent to USB standard but has a tolerance larger than that defined by USB specification.

Claims

1. A USB interface controller chip comprising:

a pair of signal ports for being connected with a pair of USB signals from external to the controller chip;

a power node for being connecting with a supply voltage; and

a built-in pull-up resistor connected between the power node and one of the pair of signal ports.

2. The chip of claim 1, wherein the pull-up resistor has a resistance of about 1.5 KΩ

with a tolerance larger than 5%.

3. The chip of claim 1, wherein the pull-up resistor has a resistance not larger than 4.6 KΩ

.

4. The chip of claim 1, wherein the one of the pair of signal ports is D+ port of a USB interface.

5. The chip of claim 1, wherein the one of the pair of signal ports is D−

port of a USB interface.