LTE Standard Module Series
EC200U_Series_Hardware_Design 46 / 94
PCM_DOUT
25
DO
PCM data output
1.8 V power domain.
If unused, keep it open.
PCM_SYNC
26
DI
PCM data frame sync
1.8 V power domain.
If unused, keep it open. The PCM
function only supports slave mode.
PCM_CLK
27
DI
PCM clock
The following figure shows the reference design of PCM and I2C interface with external Codec chip:
PCM_DIN
PCM_DOUT
PCM_SYNC
PCM_CLK
I2C_SCL
I2C_SDA
Module
4
.7
K
4
.7
K
BCLK
LRCK
DAC
ADC
SCL
SDA
B
IA
S
MICBIAS
INP
INN
LOUTP
LOUTN
Codec
1.8 V
External 26MHz Crystal
0R
NM 0R
MAIN_DCD
MCLK
Figure 22: Reference Circuit of I2C and PCM Application with External Codec Chip
It is recommended to reserve an RC (R = 22 Ω, C = 22 pF) circuit on the PCM traces, especially for
PCM_CLK.
3.14. Analog Audio Interfaces
The module provides one analog audio input channel and one analog audio output channel. The pin
definition is shown in the table below.
Table 21: Pin Definition of Analog Audio Interfaces
Interface
Pin Name
Pin No.
I/O
Description
AOUT
LOUDSPK_P
73
AO
Loudspeaker differential
NOTE
