Product Info

LTE-A Module Series

EM06 Hardware Design

EM06_Hardware_Design 29 / 63

If (U)SIM card detection function is not needed, please keep USIM_DET unconnected. A reference circuit

for (U)SIM card interface with a 6-pin (U)SIM card connector is illustrated in the following figure.

Module

USIM_VDD

USIM_GND

USIM_RESET

USIM_CLK

USIM_DATA

22R

100nF

(U)SIM Card Connector

GND

33pF 33pF 33pF

VCC

RST

CLK IO

VPP

GND

15K

USIM_VDD

Figure 15: Reference Circuit of a 6-Pin (U)SIM Card Connector

In order to enhance the reliability and availability of the (U)SIM card in customers’ applications, please

follow the criteria below in (U)SIM circuit design:

 Keep placement of (U)SIM card connector as close as possible to the module. Keep the trace length

as less than 200mm as possible.

 Keep (U)SIM card signals away from RF and VCC traces.

 Assure the ground between the module and the (U)SIM card connector short and wide. Keep the

trace width of ground and USIM_VDD no less than 0.5mm to maintain the same electric potential.

 To avoid cross-talk between USIM_DATA and USIM_CLK, keep them away from each other and

shield them with surrounded ground.

 In order to offer good ESD protection, it is recommended to add a TVS diode array with parasitic

capacitance not exceeding 10pF. The 22Ω resistors should be added in series between the module

and the (U)SIM card connector so as to suppress EMI spurious transmission and enhance ESD

protection. The 33pF capacitors are used to filter out RF interference. Please note that the (U)SIM

peripheral circuit should be close to the (U)SIM card connector.

 The pull-up resistor on USIM_DATA line can improve anti-jamming capability when long layout trace

and sensitive occasion are applied, and should be placed close to the (U)SIM card connector.

“*” means under development.

NOTE