Quectel EC25 Hardware Design

LTE Module Series
EC25 Mini PCIe Hardware Design
EC25_Mini_PCIe_Hardware_Design Confidential / Released 19 / 42
3.4. USIM Card Interface
The following table shows the pin definition of USIM card interface.
Table 6: USIM Pin Definition
EC25 Mini PCIe supports 1.8V and 3.0V USIM cards. The following figure shows a reference design for a
6-pin USIM card connector.
USIM_VDD
GND
USIM_RST
USIM_CLK
USIM_DATA
22R
22R
22R
100nF
USIM Card Connector
GND
33pF 33pF33pF
VCC
RST
CLK IO
VPP
GND
GND
33pF
15K
Module
USIM_VDD
Figure 4: Reference Circuit of USIM Card Interface with a 6-Pin USIM Card Connector
In order to enhance the reliability and availability of the USIM card in your application, please follow the
criteria below in USIM circuit design:
 Keep layout of USIM card as close to the module as possible. Keep the trace length as less than
200mm as possible.
 Keep USIM card signal away from RF and power supply traces.
 Keep the trace width of ground and USIM_VDD no less than 0.5mm to maintain the same electric
potential. The decouple capacitor of USIM_VDD should be less than 1uF and must near to USIM
card connector.
Pin No.
Pin Name
I/O
Power Domain
Description
8
USIM_VDD
PO
1.8V/3.0V
Power source for the USIM card
10
USIM_DATA
IO
1.8V/3.0V
USIM data signal
12
USIM_CLK
DO
1.8V/3.0V
USIM clock signal
14
USIM_RST
DO
1.8V/3.0V
USIM reset signal
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Quectel EC25 Specifications

General

Category	LTE Module
LTE TDD	B38/B40/B41
WCDMA	B1/B5/B8
GSM	850/900/1800/1900 MHz
Data rates	LTE Cat 4: 150 Mbps DL/50 Mbps UL
GNSS	GPS/GLONASS/BeiDou/Galileo/QZSS
Operating Temperature	-40°C to +85°C
Form Factor	LCC
Storage Temperature	-45°C to +90°C
SIM Interface	1.8V/3.0V
Antenna Interface	Main, Diversity, GNSS
LTE FDD	B1/B3/B5/B7/B8/B20
Interfaces	USB 2.0, UART, PCM, GPIO
Operating Voltage	3.3V - 4.3V
Protocols	TCP/IP, UDP, FTP, HTTP, HTTPS
Certifications	CE, FCC, PTCRB, GCF, RCM, IC