Specifications
LEON-G100/G200 - System Integration Manual
GSM.G1-HW-09002-C Preliminary System description
Page 33 of 75
Name
Description
Remarks
HS_P
Low power single-ended analog audio output
Used in handset or in headset mode
SPK_P
High power differential analog audio output
Used in ring tones or in hands free mode
SPK_N
High power differential analog audio output
Used in ring tones or in hands free mode
MIC_BIAS2
Second microphone analog bias
Single ended supply output and signal input for the second
microphone. Used in headset mode
MIC_GND2
Second microphone analog reference
Local ground of second microphone
MIC_GND1
First microphone analog reference
Local ground of the first microphone
MIC_BIAS1
First microphone analog bias
Single ended supply output and signal input for first
microphone. Used in handset or in hands free mode
Table 5: Analog Audio Signal Pins
All audio lines on an Application Board must be routed in pairs, be embedded in GND (have the ground
lines as close as possible to the audio lines), and maintain distance from noisy lines such as VCC and from
components as switching regulators.
1.9.1.3 Handset mode
Handset mode is the default audio operating mode of LEON-G100/G200 modules:
Handset microphone must be connected to inputs MIC_BIAS1/MIC_GND1
Handset receiver must be connected to output HS_P.
Figure 19 shows an example of an application circuit connecting a handset (with a 2.2 kΩ electret microphone
and a 32 Ω receiver) to the LEON-G100/G200 modules. Perform the following steps on the application circuit:
Mount a series capacitor on the HS_P line to decouple the bias.
Mount A 10 µF ceramic capacitor (e.g. Murata GRM188R60J106M) if connecting a 32 Ω receiver, or a
load with greater impedance (such as a single ended analog input of a codec). Otherwise if 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.
Mount a 33nH series inductor (e.g. Murata LQP15M33NG02) on each microphone line and a 27 pF
bypass capacitor (e.g. Murata GRM1555C1H270J) on all audio lines to minimize RF coupling and TDMA
noise.
Figure 19: Handset connector application circuit