Quectel EG915U Series Supplement

EG915U Series
Hardware Design
LTE Standard Module Series
Version: 1.0
Date: 2021-11-23
Status: Released

LTE Standard Module Series
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a) We acknowledge no liability for any injury or damage arising from the reliance upon the information.
b) We shall bear no liability resulting from any inaccuracies or omissions, or from the use of the
information contained herein.
c) While we have made every effort to ensure that the functions and features under development are
free from errors, it is possible that they could contain errors, inaccuracies, and omissions. Unless
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and exclude all liability for any loss or damage suffered in connection with the use of features and
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Copyright © Quectel Wireless Solutions Co., Ltd. 2021. All rights reserved.

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Safety Information
The following safety precautions must be observed during all phases of operation, such as usage, service
or repair of any cellular terminal or mobile incorporating the module. Manufacturers of the cellular terminal
should notify users and operating personnel of the following safety information by incorporating these
guidelines into all manuals of the product. Otherwise, Quectel assumes no liability for customers’ failure to
comply with these precautions.
Full attention must be paid to driving at all times in order to reduce the risk of an
accident. Using a mobile while driving (even with a handsfree kit) causes
distraction and can lead to an accident. Please comply with laws and regulations
restricting the use of wireless devices while driving.
Switch off the cellular terminal or mobile before boarding an aircraft. The operation
of wireless appliances in an aircraft is forbidden to prevent interference with
communication systems. If there is an Airplane Mode, it should be enabled prior to
boarding an aircraft. Please consult the airline staff for more restrictions on the use
of wireless devices on an aircraft.
Wireless devices may cause interference on sensitive medical equipment, so
please be aware of the restrictions on the use of wireless devices when in
hospitals, clinics or other healthcare facilities.
Cellular terminals or mobiles operating over radio signal and cellular network
cannot be guaranteed to connect in certain conditions, such as when the mobile bill
is unpaid or the (U)SIM card is invalid. When emergency help is needed in such
conditions, use emergency call if the device supports it. In order to make or receive
a call, the cellular terminal or mobile must be switched on in a service area with
adequate cellular signal strength. In an emergency, the device with emergency call
function cannot be used as the only contact method considering network
connection cannot be guaranteed under all circumstances.
The cellular terminal or mobile contains a transceiver. When it is ON, it receives
and transmits radio frequency signals. RF interference can occur if it is used close
to TV sets, radios, computers or other electric equipment.
In locations with explosive or potentially explosive atmospheres, obey all posted
signs and turn off wireless devices such as mobile phone or other cellular
terminals. Areas with explosive or potentially explosive atmospheres include
fuelling areas, below decks on boats, fuel or chemical transfer or storage facilities,
and areas where the air contains chemicals or particles such as grain, dust or
metal powders.

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About the Document
Revision History
Version
Date
Author
Description
-
2021-11-23
Len CHEN/Reuben WANG/
Frank WANG/Ailsa WANG
Creation of the document
1.0
2021-11-23
Len CHEN/Reuben WANG/
Frank WANG/Ailsa WANG
First official release

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Contents
Safety Information.......................................................................................................................................3
About the Document...................................................................................................................................4
Contents.......................................................................................................................................................5
Table Index...................................................................................................................................................7
Figure Index.................................................................................................................................................8
1Introduction........................................................................................................................................10
1.1. Special Mark............................................................................................................................10
2Product Overview ..............................................................................................................................11
2.1. Frequency Bands and Functions............................................................................................ 11
2.2. Key Features...........................................................................................................................12
2.3. Functional Diagram.................................................................................................................14
2.4. Pin Assignment........................................................................................................................15
2.5. Pin Description........................................................................................................................16
2.6. EVB .........................................................................................................................................24
3Operating Characteristics.................................................................................................................25
3.1. Operating Modes.....................................................................................................................25
3.2. Sleep Mode.............................................................................................................................26
3.2.1 UARTApplication Scenario............................................................................................26
3.2.2. USB Application Scenario..............................................................................................27
3.2.2.1. USBApplication with USB Remote Wakeup Function...................................27
3.2.2.2. USB Application with USB Suspend/Resume and MAIN_RI Wakeup Function
29
3.3. Airplane Mode.........................................................................................................................30
3.3.1. Hardware........................................................................................................................30
3.3.2. Software.........................................................................................................................30
3.4. Power Supply..........................................................................................................................30
3.4.1. Power Supply Pins.........................................................................................................30
3.4.2. Reference Design for Power Supply..............................................................................31
3.4.3. Requirements for Voltage Stability.................................................................................31
3.5. Turn on....................................................................................................................................32
3.5.1. Turn on with PWPKEY...................................................................................................32
3.6. Turn off ....................................................................................................................................34
3.6.1. Turn off with PWPKEY...................................................................................................35
3.6.2. Turn off with AT Command.............................................................................................35
3.7. Reset.......................................................................................................................................36
4Application Interfaces .......................................................................................................................38
4.1. Analog Audio Interfaces..........................................................................................................38
4.1.1. Audio Interfaces Design Considerations........................................................................38
4.1.2. Microphone Interface Design.........................................................................................39

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4.1.3. Receiver Interface Design..............................................................................................39
4.2. USB Interface..........................................................................................................................40
4.3. USB_BOOT Interface..............................................................................................................42
4.4. (U)SIM Interface......................................................................................................................43
4.5. I2C and PCM Interfaces.......................................................................................................45
4.6. UART Interfaces......................................................................................................................46
4.7. ADC Interface..........................................................................................................................48
4.8. SPI Interface............................................................................................................................50
4.9. PSM Interface*........................................................................................................................50
4.10. Indication Signal......................................................................................................................51
4.10.1. Network Status Indication.......................................................................................52
4.10.2. STATUS ..................................................................................................................52
4.10.3. MAIN_RI..................................................................................................................53
4.11. Control Signal..........................................................................................................................54
5Antenna Interfaces.............................................................................................................................55
5.1. Main Antenna Interface...........................................................................................................55
5.1.1. Pin Definition..................................................................................................................55
5.1.2. Operating Frequency .....................................................................................................55
5.1.3. Reference Design of Antenna Interface.........................................................................57
5.1.4. Operating Frequency .....................................................................................................58
5.2. Antenna Installation.................................................................................................................60
5.2.1. Antenna Design Requirement........................................................................................60
5.2.2. RF Connector Recommendtion .....................................................................................60
6Electrical Characteristics & Reliability............................................................................................63
6.1. Absolute Maximum Ratings ....................................................................................................63
6.2. Power Supply Ratings.............................................................................................................63
6.3. Operation and Storage Temperatures.....................................................................................64
6.4. Power Consumption................................................................................................................64
6.5. Tx Power .................................................................................................................................72
6.6. Rx Sensitivity...........................................................................................................................73
6.7. ESD.........................................................................................................................................75
7Mechanical Information.....................................................................................................................76
7.2 Mechanical Dimensions..........................................................................................................76
7.3 Recommended Footprint.........................................................................................................78
7.3 Top and Bottom Views...................................................................................................................79
8Storage, Manufacturing & Packaging...........................................................................................80
8.1 Storage Conditions..................................................................................................................80
8.2 Manufacturing and Soldering..................................................................................................81
8.3 Packaging Specifications........................................................................................................82
Packaging Process.......................................................................................................................84
9Appendix References........................................................................................................................86

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Table Index
Table 1: Special Mark.................................................................................................................................10
Table 2: Wireless Network Type..................................................................................................................11
Table 3: I/O Parameters Definition............................................................................................................. 16
Table 4: Pin Description ............................................................................................................................. 16
Table 5: Overview of Operating Modes......................................................................................................25
Table 6: Pin Definition of Power Supply..................................................................................................... 30
Table 7: Pin Definition of PWRKEY............................................................................................................32
Table 8: Pin Description of RESET_N........................................................................................................ 36
Table 9: Pin Definition of Analog Audio Interfaces..................................................................................... 38
Table 10: Functions of the USB Interface.................................................................................................. 40
Table 11: Pin Definition of USB Interface................................................................................................... 41
Table 12: Pin Definition of USB_BOOT Interface ......................................................................................42
Table 13: Pin Definition of I2C and PCM Interfaces................................................................................ 45
Table 14: Pin Definition of Main UART Interface .......................................................................................46
Table 15: Pin Definition of Debug UART Interface.....................................................................................47
Table 16: Auxiliary UART............................................................................................................................47
Table 17: Pin Definition ofADC Interface................................................................................................... 49
Table 18: Pin Definition of PSM Interface ..................................................................................................51
Table 19: Pin Definition of Indication Signal...............................................................................................51
Table 20: Working State of Network Connection Status/Activity Indication...............................................52
Table 21: Pin Definition of STATUS............................................................................................................ 53
Table 22: Behaviors of the MAIN_RI.......................................................................................................... 54
Table 23: Pin Definition of Control Signal ..................................................................................................54
Table 24: Pin Definition of RF Antennas ....................................................................................................55
Table 25: Operating Frequency of EG915U-CN........................................................................................ 55
Table 26: Operating Frequency of EG915U-EU ........................................................................................56
Table 27: Operating Frequency of EG915U-LA.........................................................................................57
Table 28: Requirements for Antenna Design .............................................................................................60
Table 30: Operating and Storage Temperatures........................................................................................64
Table 32: EG915U-EU Current Consumption............................................................................................67
Table 33: EG915U-LACurrent Consumption............................................................................................. 70
Table 34: EG915U-CN RF Output Power.................................................................................................. 72
Table 35: EG915U-EU RF Output Power...................................................................................................72
Table 36: EG915U-LARF Output Power................................................................................................... 73
Table 37: EG915U-CN Conducted RF Receiving Sensitivity.....................................................................73
Table 40: Electrostatics Discharge Characteristics (25 °C, 45 % Relative Humidity) ...............................75
Table 41: Recommended Thermal Profile Parameters.............................................................................. 82
Table 42: Related Documents....................................................................................................................86
Table 43: Terms and Abbreviations............................................................................................................86

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Figure Index
Figure 1: Functional Diagram..................................................................................................................... 14
Figure 2: EG915U Series Module Pin Assignment (Top View)..................................................................15
Figure 3: Sleep Mode Application via UART..............................................................................................26
Figure 4: Sleep Mode Application with USB Remote Wakeup..................................................................27
Figure 5: Sleep ModeApplication with MAIN_RI.......................................................................................29
Figure 6: Reference Design of Power Supply............................................................................................31
Figure 7: Power Supply Limits during Burst Transmission........................................................................ 32
Figure 8: Power Supply..............................................................................................................................32
Figure 9: Turing on the Module Using Driving Circuit................................................................................ 33
Figure 10: Turing on the Module Using Button.......................................................................................... 33
Figure 11: Power-up Timing.......................................................................................................................34
Figure 12: Timing of Turning off Module .................................................................................................... 35
Figure 13: Reference Circuit of RESET_N by Using Driving Circuit .........................................................36
Figure 14: Reference Circuit of RESET_N by Using Button......................................................................36
Figure 15: Timing of Resetting the Module................................................................................................ 37
Figure 16: Reference Design for Microphone Interface.............................................................................39
Figure 17: Reference Design for Receiver Interface................................................................................. 40
Figure 18: Reference Circuit of USBApplication....................................................................................... 41
Figure 19: Reference Circuit of USB_BOOT Interface.............................................................................. 42
Figure 20: Reference Circuit of (U)SIM Interface with an 8-Pin (U)SIM Card Connector.........................44
Figure 21: Reference Circuit of (U)SIM Interface with a 6-Pin (U)SIM Card Connector........................... 44
Figure 22: Reference Circuit of I2 C and PCMApplication withAudio Codec ..........................................46
Figure 23: Reference Circuit with Translator Chip.....................................................................................48
Figure 24: Reference Circuit with Transistor Circuit.................................................................................. 48
Figure 25: Reference Circuit of Wake up Module from PSM..................................................................... 51
Figure 26: Reference Circuit of Network Status Indication........................................................................52
Figure 27: Reference Circuits of STATUS .................................................................................................53
Figure 28: Reference Circuit of RF Antenna.............................................................................................. 58
Figure 29: Microstrip Design on a 2-layer PCB......................................................................................... 58
Figure 30: Coplanar Waveguide Design on a 2-layer PCB.......................................................................59
Figure 31: Coplanar Waveguide Design on a 4-layer PCB (Layer 3 as Reference Ground)....................59
Figure 32: Coplanar Waveguide Design on a 4-layer PCB (Layer 4 as Reference Ground)....................59
Figure 33: Dimensions of U.FL-R-SMT Connector (Unit: mm).................................................................. 61
Figure 34: Mechanicals of U.FL-LP Connectors........................................................................................61
Figure 35: Space Factor of Mated Connector (Unit: mm).......................................................................... 62
Figure 36: Module Top and Side Dimensions (Unit: mm)..........................................................................76
Figure 37: Module Bottom Dimensions......................................................................................................77
Figure 38: Recommended Footprint (TOP View).......................................................................................78
Figure 39: Top & Bottom Views of the Module........................................................................................... 79
Figure 40: Recommended Reflow Soldering Thermal Profile ...................................................................81
Figure 41: Tape Specifications................................................................................................................... 83

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Figure 42: Reel Specifications ...................................................................................................................83
Figure 43: Tape and Reel Directions..........................................................................................................84

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1Introduction
This document defines the EG915U series module and describes its air interfaces and hardware
interfaces which are connected with relate to customers’ applications.
It can help customers quickly understand interface specifications, electrical and mechanical details, as
well as other related information of the module. Associated with application notes and user guides,
customers can use this module to design and to set up mobile applications easily.
1.1. Special Mark
Table 1: Special Mark
Mark
Definition
*
Unless otherwise specified, when an asterisk (*) is used after a function, feature, interface,
pin name, AT command, or argument, it indicates that the function, feature, interface, pin,
AT command, or argument is under development and currently not supported; and the
asterisk (*) after a model indicates that the sample of such model is currently unavailable.

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2Product Overview
EG915U series module is an LTE-FDD, LTE-TDD and GSM wireless communication module, which
provides data connectivity on LTE-FDD, LTE-TDD and GPRS networks. It also provides voice
functionality, Bluetooth and Wi-Fi Scan1 to meet your specific application demands. Related information
and details are listed in the table below:
Table 2: Brief Introduction of the Module
2.1. Frequency Bands and Functions
Table 2: Wireless Network Type
1
EG915U series support Bluetooth and Wi-Fi Scan functions. Due to the shared antenna interface, the two functions
cannot be used simultaneously. Bluetooth and Wi-Fi Scan functions are optional (both supported or not), please contact
Quectel Technical Support for details.
2
Only EG915U-CN provides LTE-TDD, please consult Quectel Technical Support for details.
Categories
Packaging and pins number
126-pin; LGA
Dimensions
(23.6 ±0.2 ) mm ×(19.9 ±0.2 ) mm ×(2.4±0.2 )mm
Weight
2.5 ±0.2 g
Wireless network functions
LTE/GSM/Bluetooth/Wi-Fi Scan 1
Variants
EG915U-CN 2; EG915U-EU; EG915U-LA
Wireless Network
Type
EG915U-CN
EG915U-EU
EG915U-LA
LTE-FDD
B1/B3/B5/B8
B1/B3/B5/B7/B8/B20/B28
B2/B3/B4/B5/B7/B8/B28
/B66
LTE-TDD
B34/B38/B39/B40/B41
-
-
GSM
900/1800 MHz
850/900/1800/1900 MHz
850/900/1800/1900 MHz
Bluetooth and Wi-Fi
Scan1
2.4 GHz
2.4 GHz
2.4 GHz

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2.2. Key Features
The following table describes the detailed features of EG915U series module.
Table 4: Key Features of EG915U Series Module
Features
Description
Power Supply
⚫Supply voltage: 3.3–4.3 V
⚫Typical supply voltage: 3.8 V
Transmitting Power
EG915U-CN:
⚫EGSM900: Class 4 (33 dBm ±2 dB)
⚫DCS1800: Class 1 (30 dBm ±2 dB)
⚫LTE-FDD: Class 3 (23 dBm ±2 dB)
⚫LTE-TDD: Class 3 (23 dBm ±2 dB)
EG915U-EU:
⚫GSM850/EGSM900: Class 4 (33 dBm ±2 dB)
⚫DCS1800/PCS1900: Class 1 (30 dBm ±2 dB)
⚫LTE-FDD: Class 3 (23 dBm ±2 dB)
EG915U-LA:
⚫GSM850/EGSM900: Class 4 (33 dBm ±2 dB)
⚫DCS1800/PCS1900: Class 1 (30 dBm ±2 dB)
⚫LTE-FDD: Class 3 (23 dBm ±2 dB)
LTE Features
EG915U-CN:
⚫Supports up to Cat 1 FDD/TDD.
⚫Supports 1.4/3/5/10/15/20 MHz RF bandwidth.
⚫Supports uplink QPSK, 16QAM.
⚫Supports downlink QPSK, 16QAM and 64QAM.
⚫FDD: Max 10 Mbps (DL)/5 Mbps (UL).
⚫TDD: Max 8.96 Mbps (DL)/3.1 Mbps (UL).
EG915U-EU:
⚫Supports up to Cat 1 FDD.
⚫Supports 1.4/3/5/10/15/20 MHz RF bandwidth.
⚫Supports uplink QPSK, 16QAM.
⚫Supports downlink QPSK, 16QAM and 64QAM.
⚫FDD: Max 10 Mbps (DL)/5 Mbps (UL).
EG915U-LA:
⚫Supports up to Cat 1 FDD.
⚫Supports 1.4/3/5/10/15/20 MHz RF bandwidth.
⚫Supports uplink QPSK, 16QAM.
⚫Supports downlink QPSK, 16QAM and 64QAM.

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⚫FDD: Max 10 Mbps (DL)/5 Mbps (UL).
GSM Features
GPRS:
⚫Supports GPRS multi-slot class 12
⚫Coding scheme: CS-1/CS-2/CS-3/CS-4
⚫Max 85.6 Kbps (DL)/85.6 Kbps (UL)
Internet Protocol Features
⚫Supports TCP/UDP/PPP/NTP/NITZ/FTP/HTTP/PING/CMUX/HTTPS/
FTPS/SSL/FILE/MQTT/MMS protocols
⚫Support PAP (Password Authentication Protocol) and CHAP
(Challenge Handshake Authentication Protocol) protocols which are
usually used for PPP connection
SMS
⚫Text and PDU modes
⚫Point-to-point MO and MT
⚫SMS cell broadcast
⚫SMS storage: Stored in (U)SIM card and ME, stored in ME by default
(U)SIM Interface
⚫Supports USIM/SIM card: 1.8/3.0 V
UART Interfaces
Main UART
⚫Used for AT command communication and data transmission
⚫Baud rates reach up to 921600 bps; 115200 bps by default
⚫Supports RTS and CTS hardware flow control
Debug UART
⚫Used for the output of partial logs
⚫Baud rate: 921600 bps
⚫Only used for debug UART, cannot be used for universal UART
Auxiliary UART
SPI Interface
⚫Supports one SPI Interface (master mode only)
I2C Interface
⚫Supports one I2C Interface
PCM Interface
⚫Supports one PCM Interface
Audio Features
⚫Supports one analog audios input and one analog audios output
⚫GSM: HR/FR/EFR/AMR/AMR-WB
⚫Supports echo cancellation and noise suppression
ADC Interfaces
⚫Supports two ADC Interfaces
Network Indication
⚫NET_STATUS used to indicate the network connectivity status
AT Commands
⚫Compliant with 3G PP TS 27.007, 27.005 and Quectel enhanced AT
commands
USB_BOOT Interface
⚫Supports one download control interface
Antenna Interfaces
⚫Main antenna interface (ANT_MAIN)
⚫Bluetooth and Wi-Fi Scan antenna interface (ANT_BT/WIFI_SCAN)
⚫50 Ω impedance

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Position Fixing
⚫Support Wi-Fi Scan
Temperature Range
⚫Operation temperature range: -35 to +75 °C 4
⚫Extended temperature range: -40 to +85 °C 5
⚫Storage temperature range: -40 to +90 °C
Firmware Upgrade
⚫USB interface and DFOTA
RoHS
⚫All hardware components are fully compliant with EU RoHS directive
2.3. Functional Diagram
The following figure shows a block diagram of the module and illustrates the major functional parts.
⚫Power management
⚫Baseband
⚫Flash
⚫Radio frequency
⚫Peripheral interfaces
Baseband
PMIC
Transceiver
PA
PAM
ANT_MAIN
VBAT_RF
PWRKEY
ADCs
VDD_EXT 2x(U)SIM PCM UARTsI2C
Control
Duplex
Tx
PRx
STATUS
RESET_N
SAW
ANT_BT/WIFI_SCAN
26 MHz
DCXO
SPI Nor Flash (64Mb)
PSRAM (128Mb)
MIC
32 kHz Clock
USB SPI
SPK
Control
VBAT_BB
Figure 1: Functional Diagram
4
Within operating temperature range, the module meets 3GPP specifications.
5
Within extended temperature range, the module remains the ability to establish and maintain functions such as voice,
SMS, data transmission, etc., without any unrecoverable malfunction. Radio spectrum and radio network are not influenced,
while one or more specifications, such as Pout, may exceed the specified tolerances of 3GPP. When the temperature
returns to the operating temperature range, the module meets 3GPP specifications again.

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2.4. Pin Assignment
The following figure illustrates the pin assignment of the module.
1
2
3
4
5
6
7
11
12
13
14
15
16
17
18
50 51 52 53 54
55
58 59 60 61 62
31 30 29 28 27 26 23 22
21
20
19
10
9
8
49
48
47
46
45
44
43
40
41
42
39
38
37
36
35
34
33
32
24 25
57
56
63
64
65
66
67
68
83
84
85
86
87
88
98
97
96
95
94
93
78
77
76
75
74
73
91 92
89 90
71 72
69 70
80 79
82 81
100 99
102 101
PSM_IND
ADC1
RESERVED
SPI_CS SPI_CLK
ANT_MAIN
AP_READY
STATUS
NET_STATUS
PCM_CLK
PCM_SYNC
PCM_DIN
PCM_DOUT
W_DISABLE#
GND
USB_VBUS
USB_DP
USB_DM
RESERVED
RESERVED
RESERVED
RESERVED
PWRKEY
DBG_RXD
DBG_TXD
ADC0
VDD_EXT
MAIN_DTR
GND
MAIN_RI
MAIN_DCD
MAIN_RTS
MAIN_TXD
MAIN_RXD
VBAT_BB
MAIN_CTS
I2C_SCL
I2C_SDA
VBAT_BB
GND
GND
GND
RESERVED
VBAT_RF VBAT_RF
GND GND
ANT_BT/WIFI_SCAN
GND
GND
AUX_TXD
AUX_RXD
RESET_N
USB_BOOT
USIM2_DET
USIM2_CLK
USIM2_RST
USIM2_DATA
USIM2_VDD
SPI_DIN
SPI_DOUT
RESERVED
RESERVED
PSM_EINT
RESERVED
RESERVED
GRFC1
GRFC2
103
104
103
115
114 103
118
113
2
112
111
103
106
105
107
116 103
108
117
109
110
RESERVED
RESERVED
RESERVED
RESERVED
RESERVED
RESERVED
RESERVED
RESERVED
RESERVED
RESERVED
RESERVED RESERVED RESERVED
RESERVED RESERVED
RESERVEDRESERVED
RESERVED RESERVED
RESERVED
RESERVED
RESERVED
RESERVED
119 126
120
121
122 123
124
125
MIC_N MIC_P
SPK_P
SPK_N RESERVED
RESERVED
RESERVED
MICBIAS
Power Pins
GND Pins Signal Pins
RESERVED Pins (U)SIM Pins
USB Pins
ADC Pins UART2 Pins UART1 Pins
Debug UART Pins
SPI Pins Audio Pins
PCM Pins
USIM1_CLK
USIM1_DATA
USIM1_RST
USIM1_VDD
USIM1_GND
USIM1_DET
RESERVED
GND
PSM Pins IIC Pins
RESERVED
GND
GND GND
GND GND
GND
GND
GND
GND
GND
GND
GNDGND
GND
GND
GND
GND
GND
Figure 2: EG915U Series Module Pin Assignment (Top View)
1. USB_BOOT cannot be pulled up before startup.
2. Keep NC and RESERVED pins unconnected, all GND pins shall be connected to the ground.
3. The function of PSM is under development and it is not recommended to use it right now.
4. The module supports dual-SIM single stand by. For details, please contact Quectel Technical
Support.
NOTE

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EG915U_Series_Hardware_Design 16 / 81
2.5. Pin Description
The following tables show the pin definition of the module.
Table 3: I/O Parameters Definition
Table 4: Pin Description
Type
Description
AI
Analog Input
AO
Analog Output
AIO
Analog Input/Output
DI
Digital Input
DO
Digital Output
DIO
Digital Input/Output
OD
Open Drain
PI
Power Input
PO
Power Output
Power Supply
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
VBAT_BB
32, 33
PI
Power supply for the
module’s baseband part
Vmax = 4.3 V
Vmin = 3.3 V
Vnom = 3.8 V
It must be
provided with
sufficient current
up to 1 A
VBAT_RF
52, 53
PI
Power supply for the
module’s RF part
It must be
provided with
sufficient current
up to 2.5A
VDD_EXT
29
PO
Provide 1.8 V for
external circuit
Vnom = 1.8 V
IOmax = 50 mA
Power supply for
external GPIO’s
pull-up circuits.
Add 2.2 μF
bypass capacitor
when in use.

LTE Standard Module Series
EG915U_Series_Hardware_Design 17 / 81
If unused, keep it
open.
Power On/Off
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
PWRKEY
15
DI
Turn on/off the module
VILmax = 0.5 V
VBAT power
domain.
RESET_N
17
DI
Reset the module
VBAT power
domain.
If unused, keep it
open.
Indication Interfaces
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
STATUS
20
DO
Indicate the module's
operation status
VOHmin = 1.35 V
VOLmax = 0.45 V
1.8 V power
domain.
If unused, keep it
open
NET_STATUS
21
DO
Indicate the module's
network activity status
VOHmin = 1.35 V
VOLmax = 0.45 V
1.8 V power
domain.
If unused, keep it
open.
USB Interface
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
USB_VBUS
8
AI
USB connection detect
Vmax = 5.25 V
Vmin = 3.5 V
Vnom = 5.0 V
Typical: 5.0 V
If unused, keep it
open.
USB_DP
9
AIO
USB differential data (+)
USB 2.0
compliant.
Require
differential
impedance of
90 Ω.
If unused, keep it
open.
USB_DM
10
AIO
USB differential data (-)
(U)SIM Interface
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
USIM1_VDD
43
PO
(U)SIM1 card power
supply
IOmax = 50 mA
For 1.8 V (U)SIM:
Vmax = 1.9 V
Either 1.8 V or
3.0 V (U)SIM
card is
supported and

LTE Standard Module Series
EG915U_Series_Hardware_Design 18 / 81
Vmin = 1.7 V
For 3.0 V (U)SIM:
Vmax = 3.05 V
Vmin = 2.7 V
can be identified
automatically by
the module.
USIM1_DATA
45
DIO
(U)SIM1 card data
For 1.8 V (U)SIM:
VILmax = 0.6 V
VIHmin = 1.26 V
VOLmax = 0.45 V
VOHmin = 1.35 V
For 3.0 V (U)SIM:
VILmax = 1.0 V
VIHmin = 1.95 V
VOLmax = 0.45 V
VOHmin = 2.55 V
USIM1_CLK
46
DO
(U)SIM1 card clock
For 1.8 V (U)SIM:
VOLmax = 0.45 V
VOHmin = 1.35 V
For 3.0 V (U)SIM:
VOLmax = 0.45 V
VOHmin = 2.55 V
USIM1_RST
44
DO
(U)SIM1 card reset
For 1.8 V (U)SIM:
VOLmax = 0.45 V
VOHmin = 1.35 V
For 3.0 V (U)SIM:
VOLmax = 0.45 V
VOHmin = 2.55 V
USIM1_DET
42
DI
(U)SIM1 card hot-plug
detect
VILmin = -0.3 V
VILmax = 0.6 V
VIHmin = 1.26 V
VIHmax = 2.0 V
1.8 V power
domain. If
unused, keep
this pin open
USIM1_GND
47
-
Ground
-
Specified ground
for (U)SIM1 card
USIM2_VDD
87
PO
(U)SIM2 card power
supply
Iomax = 50 mA
1.8 V (U)SIM：
Vmax = 1.9 V
Vmin = 1.7 V
3.0 V (U)SIM：
Vmax = 3.05 V
Vmin = 2.7 V
Either 1.8 V or
3.0 V (U)SIM
card is
supported and
can be identified
automatically by
the module.

LTE Standard Module Series
EG915U_Series_Hardware_Design 19 / 81
USIM2_DATA
86
DIO
(U)SIM2 card data
1.8 V (U)SIM：
VILmax = 0.6 V
VIHmin = 1.26 V
VOLmax = 0.45 V
VOHmin = 1.35 V
3.0 V (U)SIM：
VILmax = 1.0 V
VIHmin = 1.95 V
VOLmax = 0.45 V
VOHmin = 2.55 V
USIM2_CLK
84
DO
(U)SIM2 card clock
1.8 V (U)SIM：
VOLmax = 0.45 V
VOHmin = 1.35 V
3.0 V (U)SIM：
VOLmax = 0.45 V
VOHmin = 2.55 V
USIM2_RST
85
DO
(U)SIM2 card reset
1.8 V (U)SIM：
VOLmax = 0.45 V
VOHmin = 1.35 V
3.0 V (U)SIM：
VOLmax = 0.45 V
VOHmin = 2.55 V
USIM2_DET
83
DI
(U)SIM2 card hot-plug
detect
VILmin = -0.3 V
VILmax = 0.6 V
VIHmin = 1.26 V
VIHmax = 2.0 V
1.8 V power
domain. If
unused, keep it
open
Main UART Interface
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
MAIN_CTS
36
DO
DTE clear to send signal
to DCE (connect to
DTE’s CTS)
VOLmax = 0.45 V
VOHmin = 1.35 V
1.8 V power
domain.
If unused, keep it
open.
MAIN_DTR&
MAIN_DCD&
MAIN_RI will
have a period of
time when the
module is
powered on.
MAIN_RTS
37
DI
DTE request to send
signal to DCE (connect
to DTE’s RTS)
VILmin = -0.3 V
VILmax = 0.6 V
VIHmin = 1.26 V
VIHmax = 2.0 V
MAIN_RXD
34
DI
Main UART receive
VILmin = -0.3 V
VILmax = 0.6 V
VIHmin = 1.26 V
VIHmax = 2.0 V