Quectel SG560D Series - SD Card Interface

Smart Module Series
SG560D_Series_Hardware_Design 63 / 134
⚫ To offer good ESD protection, it is recommended to add a TVS diode array with a parasitic
capacitance not exceeding 50 pF. The 22 Ω resistors should be added in series between the module
and the (U)SIM card to facilitate debugging. Add 22 pF capacitors parallel on USIM_DATA,
USIM_CLK and USIM_RST signal traces to filter RF interference, and place them as close to the
(U)SIM card connector as possible. Please note that the (U)SIM peripheral circuit should be close to
the (U)SIM card connector.
⚫ The pull-up resistor on USIM_DATA can improve anti-jamming capability of the (U)SIM card. If the
(U)SIM card traces are too long, or the interference source is relatively close, it is recommended to
add a pull-up resistor near the (U)SIM card connector.
4.3. SD Card Interface
The module supports SD 3.0 protocol. The pin definition of the SD card interface is shown below.
Table 16: Pin Definition of SD Card Interface
Pin Name
Pin No.
I/O
Description
Comment
SD_CLK
188
DO
SD card clock
Control characteristic
impedance as 45 Ω.
SD_CMD
180
DIO
SD card command
SD_DATA0
184
DIO
SDIO data bit 0
SD_DATA1
185
DIO
SDIO data bit 1
SD_DATA2
177
DIO
SDIO data bit 2
SD_DATA3
181
DIO
SDIO data bit 3
SD_DET
174
DI
SD card hot-swap detect
Active low by default.
External 1.8 V pull-up is
required.
SD_LDO9C
176
PO
Power supply for SD card
When using it, it is
recommended to add 1–4.7 μF
bypass capacitors with a total
capacitance not exceeding
18.8 μF.
SD_LDO6C
173
PO
SD card pull-up power
supply
Only for SD card pull-up. When
using it, it is recommended to
add 1–3 μF bypass capacitors
with a total capacitance not
exceeding 3 μF.