Analog Audio Interface; Analog Audio Interface Signal Descriptions; Sim Interface - Iridium 9522B Product Information Manual

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9522B L-Band Transceiver Product Information Guide

4.4 Analog Audio Interface

4.4.1 Analog Audio Interface Signal Descriptions

The analog audio interface is comprised of the analog audio input and output signals referenced to the
audio signal ground as summarized in Table 7 below. AUDIO_GND is internally connected to 0V, but
noise can be reduced by connecting audio signal returns directly to this pin, rather than to 0V.
Table 7: Analog Audio Interface Signal Descriptions
Signal Name Signal Description
MIC_AUD (pin 4) Analog audio input to LBT
SPKR_AUD (pin 9) Analog audio output from LBT
AUDIO_GND (pin 2) Analog audio ground reference

4.5 SIM Interface

An integrated SIM chip reader is provided on the 9522B LBT. An external SIM card reader may also be
interfaced as a peripheral to the 9522B LBT via the DPL bus (control/audio interface). A SIM card in the
external reader will take precedence over the SIM chip in the integrated connector when both are present.
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