LTE Standard Module Series
EC25 Hardware Design
EC25_Hardware_Design 56 / 130
Figure 24: Reference Circuit of PCM Application with Audio Codec
1. It is recommended to reserve an RC (R=22
Ω
, C=22pF) circuits on the PCM lines, especially for
PCM_CLK.
2. EC25 works as a master device pertaining to I2C interface.
3.13. SD Card Interface
EC25 supports SDIO 3.0 interface for SD card.
The following table shows the pin definition of SD card interface.
Table 15: Pin Definition of SD Card Interface
Pin Name
Pin No.
I/O
Description
Comment
SDC2_DATA3
28
IO
SD card SDIO bus DATA3
SDIO signal level can be
selected according to SD
card supported level,
please refer to SD 3.0
protocol for more details.
If unused, keep it open.
SDC2_DATA2
29
IO
SD card SDIO bus DATA2
SDC2_DATA1
30
IO
SD card SDIO bus DATA1
SDC2_DATA0
31
IO
SD card SDIO bus DATA0
SDC2_CLK
32
DO
SD card SDIO bus clock
NOTES