Front Panel I/O Connectivity Design Guide

Front Panel Legacy I/O

associated signal pins, connected directly to their respective pins on the dongle stake pin header.

The SENSE_SEND signal is split and routed through the PORT1 and PORT2 isolated switches.

The other contact of each isolated switch, are routed to their respective sense return signals,

SENSE1_RETURN and SENSE2_RETURN. This functionality, together with the Rjd_PORT1

and Rjd_PORT2 resistors on the motherboard as shown in Figure 5, informs the audio driver of

jack insertion or removal, which is necessary for dynamic re-taking of the front panel jacks.

Finally, a 1 k pulldown is required on the PRESENCE# pin to signal BIOS that the Intel

Audio front panel dongle is connected to the system.

PORT1 L

GND

JACK2 R

JACK2 L

910

PORT1 R

PORT2 R

PORT2 L

PRESENCE#

SENSE1_RETURN

SENSE_SEND

1kΩ

JACK 1

JACK 2

Normally Open

Isolated Switch

2X5 Stake Pin Header (100mil Pitch)

SENSE2_RETURN

EMI Filter

220pF

** Note: Z

should be 600Ω or greater @ 100MHz with a low Q (broad Impedance curve over frequency)

Figure 6. Intel

HD Audio Front Panel Dongle Implementation