Front Panel I/O Connectivity Design Guide

Front Panel High Speed I/O Bus

Figure 8. Front Panel Single Port USB Header (Top View)

Manufacturer's Part Number: Foxconn HF11050-UD5 (or equivalent) (leaded)

3.2.6 Single Port USB Header Pin Assignments

Table 9. Single Port USB Header Pin Assignments

Pin Signal Names Description

1 VREG_FP_USBPWR

Front panel USB power (Ports 0) [+5 V or +5 V Dual]

Note

2 USB_FP_P0- Front panel USB Port 0 negative signal

3 USB_FP_P0+ Front panel USB Port 0 positive signal

4 Ground

5 Key

Note: +5 V Dual switches between +5 V and +5V Standby depending on the current board state.

3.2.7 Dual USB Header Usage

Motherboard designs that require the ability to support multiple single port USB cable connections

or the ability to be re-configured to support a Dual USB Header configuration will benefit from the

header shown in the Dual Port Header drawing (Figure 7). This header can be used to support two

side by side single port USB cable connections, one single port USB cable connection, or a single

two port USB cable connection.

3.2.8 Electrical Considerations

Care should be taken when implementing USB designs such that signal quality and power delivery

are not compromised. Certain basic guidelines should be followed:

• There should be only one over current protection fuse between the motherboard and the USB

connector in the front panel USB dongle (see Section 3.2.8.1).

• EMI and ESD components should be included (see Sections 3.2.8.3 and 3.2.8.4).

• Front panel and rear panel USB connectors should use separate fuses.

The location of the Front Panel I/O header on the motherboard should take into account the trace

lengths on the motherboard and interface board as well as the front panel cable length, otherwise

signal quality could be affected. See the USB 2.0 specification for details and testing information.

3.2.8.1 Fuse Element

The fuse element used for USB power delivery must be placed down on the motherboard so the

following functions can be performed:

• Protects the motherboard from damage in case of a short between USBPRW and ground.

• Provides some measure of protection from damage if an unkeyed cable is inadvertently plugged

into the front panel USB connector and shorts USBPRW.