LEON-G100 / LEON-G200 - System Integration Manual
GSM.G1-HW-09002-G3
Preliminary
System description
Page 66 of 125
Reference
Description
Part Number - Manufacturer
C1, C2, C3, C4
10 µF Capacitor X5R 0603 5% 6.3 V
GRM188R60J106M - Murata
R1, R3
0
Ω
Resistor 0402 5% 0.1 W
RC0402JR-070RL - Yageo Phycomp
R2, R4
Not populated
Table 25: Example of components for the connection to an analog audio device
1.10.2
Digital Audio interface
LEON-G100 / LEON-G200 modules support a bidirectional 4-wire I
2
S digital audio interface. The module acts as
master only. Table 26 lists the I
2
S pins:
Name
Description
Remarks
I2S_WA
I
2
S word alignment
Module output (master).
1
I2S_TXD
I
2
S transmit data
Module output
I2S_CLK
I
2
S clock
Module output (master)
I2S_RXD
I
2
S receive data
Module input
Internal active pull-up to 2.85 V enabled.
Table 26: I
2
S interface pins
I
2
S interface pins ESD sensitivity rating is 1 kV (HBM JESD22-A114F). A higher protection level could be
required if the lines are externally accessible on the application board. A higher protection level can be
achieved mounting an ESD protection (e.g. EPCOS CA05P4S14THSG varistor array) on the lines
connected to these pins if they are externally accessible on the application board.
The I
2
S interface can be can be used in two modes:
PCM mode: I2Sx
Normal I
2
S mode: I2Sy
Beyond the supported transmission modality, the main difference between the PCM mode and the normal I
2
S
mode is represented by the logical connection to the digital audio processing system integrated in the chipset
firmware (see Figure 41):
PCM mode provides complete audio processing functionality
Normal I
2
S mode: digital filters, digital gains, side tone, some audio resources as tone generator, info tones
(e.g. free tone, connection tone, low battery alarm), and ringer are not available
The I
2
S interface is activated and configured using AT commands, see the
u-blox AT Commands Manual
(AT+UI2S command).
If the I
2
S interface is used in PCM mode, digital path parameters can be configured and saved as the normal
analog paths, using appropriate path index as described in the
u-blox AT Commands Manual
[2]. Analog gain
parameters of microphone and speakers are unused when digital path is selected.
Refer to
[2], AT+UI2S command for possible combinations of connections
and settings.
Figure 40 shows an application circuit for digital audio interface.
1
Check device specifications to ensure compatibility of supported modes to LEON-G100/G200 module. Add a test point to provide access to
the pin for debugging.
