Smart LTE Module Series
Smart EVB G2 User Guide
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Audio Interfaces
4.7.
Smart EVB G2 provides three analog audio outputs including one mono loudspeaker, one mono
earphone, and one stereo headset. The Smart EVB G2 also provides three analog audio inputs including
two single-ended and one differential microphone inputs. One single-ended microphone input is used for
headset interface. One single-ended and one differential microphone inputs are used for microphone
interfaces.
4.7.1. Loudspeaker Interface
Smart EVB G2 provides one loudspeaker interface and the loudspeaker is soldered onto the Smart EVB
G2 via test point J1203. The following figure shows a reference circuit design for loudspeaker interface.
SPK_P
SPK_N
1.0nF
Close to speaker
ESD
ESD
FB
FB
Smart EVB G2
1.0nF
J1203
Figure 26: Reference Design for Loudspeaker Interface
4.7.2. Headset Interface
The following figure shows a reference circuit design for headset interface.
