Table of Contents
Advertisement
To ensure better performance and avoid damage to (U)SIM cards, please follow the criteria below in
(U)SIM circuit design:
⚫
Place the (U)SIM card connector as close to the module as possible. Keep the trace length of (U)SIM
card signals as less than 200 mm as possible.
⚫
Keep (U)SIM card signals away from RF and VBAT traces.
⚫
Reserve a filter capacitor for USIM_VDD, and its maximum capacitance should not exceed 1 μF.
Additionally, place the capacitor near the
⚫
To avoid cross-talk between USIM_DATA and USIM_CLK, keep them away from each other and
shield them with ground. USIM_RST also needs ground protection.
⚫
In order to ensure good ESD protection, it is recommended to add a TVS diode array with parasitic
capacitance not exceeding 50 pF. Add 22 Ω resistors in series between the module and (U)SIM card
to suppress EMI spurious transmission and enhance ESD protection. Please note that the (U)SIM
peripheral circuit should be close to the (U)SIM card connector.
⚫
Add 22 pF capacitors in parallel on USIM_DATA, USIM_CLK and USIM_RST signal lines to filter RF
interference, and place them as close to the
3.11. SD Card Interface
The module supports SD 3.0 specifications. The pin definition of the SD card interface is shown below.
Table 15: Pin Definition of SD Card Interface
Pin Name
Pin No.
SD_CLK
39
SD_CMD
40
SD_DATA0
41
SD_DATA1
42
SD_DATA2
43
SD_DATA3
44
SD_DET
45
SD_VDD
38
SC200L_Series(Dual-band Wi-Fi)_Hardware_Design
card connector.
(U)SIM
(U)SIM
I/O
Pin Description
DO
SD card clock
DIO
SD card command
DIO
DIO
SDIO data bits
DIO
DIO
DI
SD card hot-plug detect
PO
SD card power supply
card connector as possible.
Comment
50 Ω characteristic impedance.
Active low.
If a large-capacity T-Flash card is to
be connected, it is recommended to
add an LDO which can supply 1 A
current.
Smart Module Series
46 / 111
Advertisement
Table of Contents
