LTE-A Module Series
EG12 Hardware Design
EG12_Hardware_Design 54 / 97
Clock and mode can be configured by AT command, and the default configuration is master mode using
short frame synchronization format with 2048kHz PCM_CLK and 8kHz PCM_SYNC. Please refer to
document [2]
for details about
AT+QDAI
command.
The following figure shows a reference design of PCM interface with an external codec IC.
PCM_IN
PCM_OUT
PCM_SYNC
PCM_CLK
I2C_SCL
I2C_SDA
Module
1.8V
4
.7
K
4
.7
K
BCLK
LRCK
DAC
ADC
SCL
SDA
B
IA
S
MICBIAS
INP
INN
LOUTP
LOUTN
Codec
Figure 26: Reference Circuit of PCM Application with Audio Codec
1. It is recommended to reserve an RC (R=22
Ω, C=22pF) circuit on the PCM lines, especially for
PCM_CLK.
2. EG12 works as a master device pertaining to I2C interface.
PCM_OUT
68
DO
PCM data output
1.8V power domain.
If unused, keep it open.
PCM_SYNC
65
IO
PCM data frame
synchronization
signal
1.8V power domain.
In master mode, it is an output signal.
In slave mode, it is an input signal.
If unused, keep it open.
PCM_CLK
67
IO
PCM data clock
1.8V power domain.
In master mode, it is an output signal.
In slave mode, it is an input signal.
If unused, keep it open.
I2C_SDA
42
OD
I2C serial data
An external pull-up resistor is required.
If unused, keep it open.
I2C_SCL
43
OD
I2C serial clock
An external pull-up resistor is required.
If unused, keep it open.
I2S_MCLK
152
DO
Clock output
Provide a digital clock output for an
external audio codec.
If unused, keep it open.
NOTES