Specifications

LEON-G100/G200 - System Integration Manual
GSM.G1-HW-09002-C Preliminary System description
Page 36 of 75
Figure 22: Hands free mode application circuit
1.9.1.6 Connection to an external analog audio device
When the LEON-G100/G200 module analog audio output is connected to an external audio device, HS_P analog
audio output can be used. A 10 µF series capacitor (e.g. Murata GRM188R60J106M) must be inserted between
the HS_P output and the single ended analog input of the external audio device (to decouple the bias). An
additional single-ended to differential circuit is required for audio devices with a differential analog input. The
signal levels can be adapted by setting gain using AT commands, but additional circuitry must be inserted if the
HS_P output level of the module is too high for the input of the audio device.
If LEON-G100/G200 module analog audio input is connected to an external audio device,
MIC_BIAS1/MIC_GND1 can be used (default analog audio input of the module). Insert a 10 µF series capacitor
(e.g. Murata GRM188R60J106M) between the single ended analog output of the external audio device and
MIC_BIAS1. Connect the reference of the single ended analog output of the external audio device to
MIC_GND1. If the external audio device is provided with a differential analog output, insert an additional
differential to single ended circuit. The signal levels can be adapted by setting gain using AT commands, but
additional circuitry must be inserted if the output level of the audio device is too high for MIC_BIAS1.
Examples of connecting the LEON-G100/G200 modules to external audio applications are shown in Figure 23.
LEON-G100/G200
43
44
38
39
MIC_BIAS1
MIC_GND1
SPK_N
SPK_P
LEON-G100/G200
43
44
38
39
MIC_BIAS1
MIC_GND1
SPK_N
SPK_P