Specifications

Signal Descriptions

ID052914 Non-Confidential

A.1 Audio CODEC interface

The motherboard provides three stacked 3.5mm jack connectors on the rear panel that enable

you to connect to the analog microphone and auxiliary line level input and output on the

CODEC. If no jack plug is inserted, the tip and sleeve of both the Mic In and Line In jack sockets

are connected to analog ground to help prevent noise pickup. Figure A-1 shows the pinouts of

the sockets.

Note

A link, LK1, on the motherboard enables a 5V bias voltage to be applied to the microphone.

The available link options are:

• Fit A-B For BIAS at the tip, standard active microphone.

• Fit B-C For BIAS at the middle sleeve.

• Omit For no BIAS, passive microphone.

When no plug is inserted, both the Microphone and Line In jack sockets tip and sleeve are

connected to analog ground to avoid noise pickup.

Figure A-1 Audio connectors

AMP_L

AMP_R

CODEC_LINE_IN_L

CODEC_LINE_IN_R

AGND

CODEC_MIC2

AGND

CODEC_MIC1

Mic in

Line in

Line out

AGND

J12

AGND