Specifications
LEON-G100/G200 - System Integration Manual
GSM.G1-HW-09002-C Preliminary System description
Page 34 of 75
Figure 20: Application circuits to connect the LEON module to external audio devices with proper single-ended or differential
analog audio inputs/outputs
1.9.1.4 Headset mode
The audio path is automatically switched from handset mode to headset mode when a rising edge is detected by
the module on HS_DET. The audio path returns to the handset mode when the line returns to low level.
The audio path used in headset mode:
Headset microphone must be connected to MIC_BIAS2/MIC_GND2
Headset receiver must be connected to HS_P
Figure 21 shows an application circuit connecting a headset (with a 2.2 kΩ electret microphone and a 32 Ω
receiver) to the LEON-G100/G200 modules. Pin 1 & 2 are shorted in the headset connector, causing HS_DET to
be pulled low. When the headset plug is inserted HS_DET is pulled internally by the module, causing a rising
edge for detection.
Perform the following steps on the application board (see Figure 21):
Mount a series capacitor on the HS_P line to decouple the bias. 10 µF ceramic capacitor (e.g. Murata
GRM188R60J106M) is required if a 32 Ω receiver or a load with greater impedance (as a single ended
analog input of a codec) is connected to the line. When a 16 Ω receiver is connected to the line, a
ceramic capacitor with greater nominal capacitance must be used: a 22 µF series capacitor (e.g. Murata
GRM21BR60J226M) is required
LEON-G100/G200
37
43
44
MIC_BIAS1
MIC_GND1
HS_P
Audio Device
Single-ended Analog Output
Reference
Single-ended Analog Input
10 µF
GND
Reference
10 µF
LEON-G100/G200
37
43
44
MIC_BIAS1
MIC_GND1
HS_P
Audio Device
Positive Analog Input
10 µF
GND
Reference
Negative Analog Input
Single-ended
to
Differential
Positive Analog Output
10 µF
Reference
Negative Analog Output
Differential
to
Single-ended
LEON-G100/G200
37
43
44
MIC_BIAS1
MIC_GND1
HS_P
Audio Device
Single-ended Analog Output
Reference
Single-ended Analog Input
10 µF
GND
Reference
10 µF
LEON-G100/G200
37
43
44
MIC_BIAS1
MIC_GND1
HS_P
Audio Device
Positive Analog Input
10 µF
GND
Reference
Negative Analog Input
Single-ended
to
Differential
Positive Analog Output
10 µF
Reference
Negative Analog Output
Differential
to
Single-ended