Audio Interfaces; Figure 13. Audio Interfaces - Motorola c18 Developer's Manual

Hardware Description
3.7

AUDIO INTERFACES

c18 has three analog audio interfaces, including:
• Handset interface
• Headset interface
• Hands-free (auxiliary) interface
These interfaces are internally muxed. Therefore, only one interface can be active at a time. The hands-free (auxiliary audio)
interface is available for all three types of interface connectors. The handset and headset interfaces are supported only on c18
models that use the 70-pin connector.
INTERFACE CONNECTOR
HEADSET_MIC
HEADSET_SP
HEADSET_INT_N
AUDIO_OUT_ONOFF
28
MIC_IN+
MIC_IN-
EARPIECE+
EARPIECE-
2.2kΩ
AGND
AUDIO_IN
N.O.
ON/OFF SWITCH
4.7kΩ
GND
AGND

Figure 13. Audio Interfaces

OPTIONAL
SEND_END
N.C.
AGND
AGND
AGND
AUX. AUDIO INPUT
AUX. AUDIO OUTPUT
HANDSET INTERFACE
HEADSET INTERFACE
HANDS-FREE
(AUXILARY AUDIO)
INTERFACE
98-08901C63-A