User's Manual

SARA-G3 and SARA-U2 series - System Integration Manual
UBX-13000995 - R18 Advance Information Design-in
Page 146 of 206
SARA-G340
SARA-G350
49
MIC_P
R1
R2 R4
44
SPK_P
48
MIC_N
45
SPK_N
R3
C1
46
MIC_BIAS
47
MIC_GND
C2
C3
C6 C7
L2
L1
C5C4
LSPK
Loud-Speaker
Connector
J2
Microphone
Connector
MIC
J1
OUT+
IN+
GND
U1
OUT-
IN-
C8
C9
R5
R6
VDD
C11C10
Audio
Amplifier
VCC
D3
D1
D4
D2
Figure 83: Analog audio interface hands-free mode application circuit
Reference Description Part Number – Manufacturer
C1, C10
10 μF Capacitor Ceramic X5R 0603 20% 6.3 V
GRM188R60J106ME47 – Murata
C2, C3, C11
100 nF Capacitor Ceramic X7R 0402 10% 16 V
GRM155R71C104KA88 – Murata
C4, C5, C6, C7
27 pF Capacitor Ceramic C0G 0402 5% 25 V
GRM1555C1H270JA01 – Murata
C8, C9
47 nF Capacitor Ceramic X7R 0402 10% 16V
GRM155R71C473KA01 – Murata
D1, D2, D3, D4
Low Capacitance ESD Protection
CG0402MLE-18G - Bourns
J1
Microphone Connector
Various Manufacturers
J2
Speaker Connector
Various Manufacturers
L1, L2
82 nH Multilayer inductor 0402
(self resonance frequency ~1 GHz)
LQG15HS82NJ02 – Murata
LSPK
8 : Loud-Speaker
Various Manufacturers
MIC
2.2 kΩ Electret Microphone
Various Manufacturers
R1, R2, R3, R4
2.2 kΩ Resistor 0402 5% 0.1 W
RC0402JR-072K2L – Yageo Phycomp
R5, R6
0 Ω Resistor 0402 5% 0.1 W
RC0402JR-070RL – Yageo Phycomp
U1
Filter-less Mono 2.8 W Class-D Audio Amplifier
SSM2305CPZ – Analog Devices
Table 54: Example of components for analog audio interface hands-free mode application circuit
If the analog audio interface is not used, the analog audio pins (MIC_BIAS, MIC_GND, MIC_P, MIC_N,
SPK_P, SPK_N) can be left unconnected on the application board.