LISA-U series - System Integration Manual
UBX-13001118 - R17
Advance information
System description
Page 103 of 190
The external audio codec is controlled by the cellular module using the DDC (I
2
C) interface: this interface can be
used to communicate with u-blox GNSS receivers and at the same time to control an external audio codec on all
LISA-U2 series modules versions except LISA-U200-00S.
The
V_INT
supply output of the cellular module provides the supply to the external audio codec, defining a
proper voltage level for the digital interfaces.
Additional components are provided for EMC and ESD immunity conformity according to European Norms for
R&TTE Directive (99/5/EC) and EMC Directive (89/336/EEC) compliance. The recommended parts for EMC and
ESD immunity conformity are: a 10 nF bypass capacitor (e.g. Murata GRM155R71C103KA88) and a proper series
chip ferrite bead noise/EMI suppression filter (e.g. Murata BLM15HD182SN1) provided on each microphone line
input and speaker line output of the external codec as described in Figure 56 and Table 47.
An external audio codec can be connected to the I
2
S digital audio interface of LISA-U120 or LISA-U130 modules
as shown in the application circuit described in Figure 56. In this case the application processor should properly
control the audio codec by I
2
C interface and should properly provide clock reference to the audio codec.
53
I2S1_CLK
54
I2S1_WA
R2
R1
BCLK
GND
U1
LRCLK
LISA-U2 series
(except LISA-U200-00S)
Audio
Codec
40
I2S1_TXD
39
I2S1_RXD
SDIN
SDOUT
46
SDA
45
SCL
SDA
SCL
52
CODEC_CLK
MCLK
GND
IRQn
R3
C3
C2
C1
4
V_INT
VDD
1V8
MICBIAS
C4
R4
C5
C6
EMI1
MICLN
MICLP
D1
Microphone
Connector
EMI2
MIC
C12 C11
J1
MICGND
R5
C8
C7
D2
SPK
Speaker
Connector
OUTP
OUTN
J2
C10 C9
C14 C13
EMI3
EMI4
Figure 56: I
2
S interface application circuit with an external audio codec to provide voice capability
Reference
Description
Part Number – Manufacturer
C1
100 nF Capacitor Ceramic X5R 0402 10% 10V
GRM155R71C104KA01 – Murata
C2, C4, C5, C6
1 µF Capacitor Ceramic X5R 0402 10% 6.3 V
GRM155R60J105KE19 – Murata
C3
10 µF Capacitor Ceramic X5R 0603 20% 6.3 V
GRM188R60J106ME47 – Murata
C7, C8, C9, C10
27 pF Capacitor Ceramic COG 0402 5% 25 V
GRM1555C1H270JZ01 – Murata
C11, C12, C13, C14
10 nF Capacitor Ceramic X5R 0402 10% 50V
GRM155R71C103KA88 – Murata
D1, D2
Low Capacitance ESD Protection
USB0002RP or USB0002DP – AVX
EMI1, EMI2, EMI3,
EMI4
Chip Ferrite Bead Noise/EMI Suppression Filter
1800 Ohm at 100 MHz, 2700 Ohm at 1 GHz
BLM15HD182SN1 – Murata
J1
Microphone Connector
Various manufacturers
J2
Speaker Connector
Various manufacturers
MIC
2.2 k
Electret Microphone
Various manufacturers
R1, R2
4.7 k
Ω
Resistor 0402 5% 0.1 W
RC0402JR-074K7L - Yageo Phycomp
