CLM920_RC3(RV3 RE3)LCC Series CAT1 Module Hardware Manual
Shanghai YUGE Information Technology Co., Ltd.
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30
SDC2_D1
IO
SDIO bus DATA1
31
SDC2_D0
IO
SDIO bus DATA0
32
SDC2_CLK
DO
SDIO bus clock
33
SDC2_CMD
IO
SDIO bus command
34
VDD_SD
PO
SD card power supply
The SD card reference design of the CLM920_RC3 module is shown below
:
Figure 3-24 SD card interface reference circuit diagram
The maximum output current of the module power supply VDD_SD is 400mA, which can
be used for SD card circuit power supply.
The SDIO bus is a high-speed signal line, and the characteristic impedance needs to be
controlled at about 50 ohms when designing the PCB.
The length of the signal line should be less than 25mm. The distance between the signal
lines should be 2 times the width of the signal line and the ground should be as far away
as possible from other lines that may cause interference
The SDIO signal line needs to be connected in series with a 0 ohm resistor to facilitate
adjustment of signal quality.
In order to ensure good ESD performance, it is recommended to add TVS tubes to the SD
card pins and place them close to the pins.