Sd Card Interface - Quectel EC25-AUX Hardware Design

Figure 24: Reference Circuit of PCM Application with Audio Codec
NOTES
1. It is recommended to reserve an RC (R=22Ω, 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.
SDC2_DATA3 28
SDC2_DATA2 29
SDC2_DATA1 30
SDC2_DATA0 31
SDC2_CLK 32
EC25_Hardware_Design
I/O Description
IO SD card SDIO bus DATA3
IO SD card SDIO bus DATA2
IO SD card SDIO bus DATA1
IO SD card SDIO bus DATA0
DO SD card SDIO bus clock
LTE Standard Module Series
EC25 Hardware Design
Comment
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.
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