International Computer Hardware User Manual

CX-MB-EVA2 User's Manual Hardware

4.9 Audio

An AC’97 codec V2.2 is connected to the AC link of the COM Express module. Footprint

and circuit are compatible to following AC’97 codecs:

 VIA VT1612A

 Realtek ALC650

Following LF signals are provided by the AC’97 codec:

 Mono Microphone

 Stereo LineIn

 Stereo LineOut

 Stereo Headphone

Alternatively a VIA VT1708 HDA codec can be connected to the AC link of the COM

Express module. The audio interface can be selected with Jumper J0701.

Following LF signals are provided by the HDA codec:

 Stereo LineIn

 Stereo LineOut

 Stereo Microfon

 Mono Center / Mono LFE

 Stereo Surround

 Stereo Side

4.9.1 AC'97 codec

4.9.1.1 Mono-Microphone

Bias voltage for capacitor microphones is provided.

Specification:

 References: X18

 Connector: Kycon ST-3000Mono-Microphone

 Pinout: Refer to Table 8

Pin Signal name Function

1 GND Ground

2 MIC_BIAS Bias initial load (ring)

3 MIC NF signal (tip)

Table 13 Pinout Microphone