Sd Card Interface - Quectel SC200L-EM Hardware Design

Figure 15: Reference Circuit for (U)SIM Interface with a 6-pin (U)SIM Card Connector
In order to ensure good performance and avoid damage of (U)SIM cards, please follow the criteria listed
below during (U)SIM circuit design:
 Keep placement of (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.
 A filter capacitor shall be reserved for USIM_VDD, and its maximum capacitance should not exceed
1μF. The capacitor should be placed near to (U)SIM card.
 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 offer good ESD protection, it is recommended to add a TVS diode array with parasitic
capacitance not exceeding 50pF. The 22Ω resistors should be added in series between the module
and (U)SIM card so as 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.
 The 22pF capacitors should be added in parallel on USIM_DATA, USIM_VDD, USIM_CLK and
USIM_RST signal lines so as to filter RF interference, and they should be placed as close to the
(U)SIM card connector as possible.

3.11. SD Card Interface

SC200L SD Card Interface supports the SD 3.0 protocol. The pin definition of the SD card interface is
shown below.
Table 12: Pin Definition of SD Card Interface
Pin Name Pin No
SC200L_Hardware_Design
I/O
Descrip Comment
tion
SC200L Hardware Design
Pin Name
36 / 103