Modem User Manual

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5.9 Analogue Audio
Pin Name Direction Function
53 MICIP Input Microphone input positive
54 MICIN Input Microphone input negative
55 EARP Output Earpiece output positive
Low-level
56 EARN Output Earpiece output negative
57 AUXO Output Auxiliary audio from module to host
59 AUXI Input Auxiliary audio to module from host
High-level
60 AREF - Analogue reference
The analogue audio signals comprise of two audio inputs to the module, and two
audio output from the module. The Auxiliary interface signals are single-ended,
whilst the MIC and EAR interface signals are differential. Analogue audio can be used
for various configurations, including a car kit mode, portable hands free and
speakerphone (with an additional output gain stage).
Five audio profiles are available for GR64 users to configure various modes of
operation. Each profile is factory set to represent different modes, typical of general
usage. The customer can modify profiles to optimize acoustic performance to their
specific application.
The analogue inputs and outputs share common uplink and downlink chains which
are multiplexed, and selectively switched by the user through AT-commands.