Fibocom L831-EAU-01 Instructions for use

L831-EAU-01 Hardware User Manual
Version: 1.0.0
Update date: 2017.05.22

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Applicability Table
No.
Product model
Description
1
L831-EAU-01
2 modes and 6 bands

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Copyright
Copyright © 2017Fibocom Wireless Inc. All rights reserved.
Without the prior written permission of the copyright holder, any company or individual is prohibited to
excerpt, copy any part of or the entire document, or distribute the document in any form.
Notice
The document is subject to update from time to time owing to the product version upgrade or other
reasons. Unless otherwise specified, the document only serves as the user guide. All the statements,
information and suggestions contained in the document do not constitute any explicit or implicit
guarantee.
Version Record
Version
Update Date
Description
V1.0.0
2017-05-22
Initial release

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Contents
1 Foreword.......................................................................................................................................... 6
1.1 Introduction........................................................................................................................................... 6
1.2 Reference Standard............................................................................................................................ 6
1.3 Related Documents............................................................................................................................. 6
2 Overview...........................................................................................................................................7
2.1 Introduction........................................................................................................................................... 7
2.2 Specification..........................................................................................................................................7
2.3 Application Framework........................................................................................................................8
2.4 Hardware Framework..........................................................................................................................9
3 Application Interface..................................................................................................................... 9
3.1 M.2 Interface.........................................................................................................................................9
3.1.1 Pin Distribution................................................................................................................................. 10
3.1.2 Pin Definition.....................................................................................................................................11
3.2 Power Supply..................................................................................................................................... 15
3.2.1 Power Supply................................................................................................................................... 15
3.2.2 Logic level......................................................................................................................................... 16
3.2.3 Power Consumption........................................................................................................................17
3.3 Control Signal.....................................................................................................................................17
3.3.1 Module Start-Up...............................................................................................................................18
3.3.1.1 Start-up Circuit................................................................................................................................................18
3.3.1.2 Start-up Timing Sequence............................................................................................................................19
3.3.2 Module Shutdown............................................................................................................................19
3.3.2.1 Software Shutdown........................................................................................................................................20
3.3.2.2 Hardware Shutdown...................................................................................................................................... 20
3.3.3 Host Reboot......................................................................................................................................21
3.3.4 Module Reset................................................................................................................................... 22
3.4 USB Interface..................................................................................................................................... 23
3.4.1 USB Interface Definition................................................................................................................. 23
3.4.2 USB2.0 Interface Application.........................................................................................................24
3.5 USIM Interface................................................................................................................................... 24
3.5.1 USIM Pins......................................................................................................................................... 24
3.5.2 USIM Interface Circuit.....................................................................................................................25
3.5.2.1 N.C. SIM Card Slot........................................................................................................................................ 25

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3.5.3 USIM Hot-Plugging..........................................................................................................................26
3.5.4 USIM Design.................................................................................................................................... 26
3.6 Status Indicator.................................................................................................................................. 26
3.6.1 LED#1Signal.....................................................................................................................................27
3.6.2 WAKE_WWAN#...............................................................................................................................27
3.7 Interrupt Control................................................................................................................................. 28
3.7.1 W_DISABLE#...................................................................................................................................28
3.7.2 GNSS Control...................................................................................................................................28
3.8 Clock Interface................................................................................................................................... 29
3.9 Config Interface..................................................................................................................................29
3.10 Other Interfaces............................................................................................................................... 29
4 Radio Frequency..........................................................................................................................30
4.1 RF Interface........................................................................................................................................30
4.1.1 RF Interface Functionality.............................................................................................................. 30
4.1.2 RF Connector Characteristic......................................................................................................... 30
4.1.3 RF Connector Dimension...............................................................................................................30
4.2 Operating Band.................................................................................................................................. 32
4.3 Transmitting Power............................................................................................................................32
4.4 Receiver Sensitivity........................................................................................................................... 33
4.5 GNSS...................................................................................................................................................33
4.6 Antenna Design..................................................................................................................................34
5 Structure Specification.............................................................................................................. 35
5.1 Product Appearance..........................................................................................................................35
5.2 Dimension of Structure..................................................................................................................... 35
5.3 M.2 Interface Model...........................................................................................................................36
5.4 M.2 Connector....................................................................................................................................36
5.5 Storage................................................................................................................................................37
5.5.1 Storage Life...................................................................................................................................... 37
5.6 Packing................................................................................................................................................37
5.6.1 Tray Package................................................................................................................................... 38
5.6.2 Tray size............................................................................................................................................39

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1 Foreword
1.1 Introduction
The document describes the electrical characteristics, RF performance, dimensions and application
environment, etc. of L831-EAU-01 module. With the assistance of the document and other instructions,
the developers can quickly understand the hardware functions of L831-EAU modules and develop
products.
1.2 Reference Standard
The design of the product complies with the following standards:
3GPP TS 34.121-1 V10.8.0: User Equipment (UE) conformance specification;Radio
transmission and reception (FDD);Part 1: Conformance specification
3GPP TS 36.521-1 V10.6.0: User Equipment (UE) conformance specification; Radio
transmission and reception; Part 1: Conformance testing
3GPP TS 21.111 V10.0.0: USIM and IC card requirements
3GPP TS 51.011 V4.15.0: Specification of the Subscriber Identity Module -Mobile Equipment
(SIM-ME) interface
3GPP TS 31.102 V10.11.0: Characteristics of the Universal Subscriber Identity Module (USIM)
application
3GPP TS 31.11 V10.16.0: Universal Subscriber Identity Module (USIM) Application
Toolkit(USAT)
3GPP TS 36.124 V10.3.0: ElectroMagnetic Compatibility (EMC) requirements for mobile
terminals and ancillary equipment
3GPP TS 27.007 V10.0.8: AT command set for User Equipment (UE)
PCI Express M.2 Specification Rev0.9-3
1.3 Related Documents
The performance test report of L831-EAU module
RF Antenna Application Design Specification
L8-Family System Driver Integration and Application Guidance
L8-Family AT Commands Manual

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2 Overview
2.1 Introduction
The L831-EAU is a highly integrated 4G wireless communication module which adopts the standard M.2
interface, and supports LTE FDD/WCDMA systems.
2.2 Specification
Specification
Operating Band
L831-EAU-01
LTE FDD: Band 1, 3, 7, 8, 20, 28
WCDMA/HSPA+: Band I, VIII
Data Transmission
LTE FDD
150Mbps DL/50Mbps UL(Cat 4)
UMTS/HSPA+
UMTS:384 kbps DL/384 kbps UL
DC-HSDPA+:42Mbps DL(Cat 24)/5.76Mbps UL(Cat 6)
Power Supply
DC 3.135V～4.4V, Typical 3.3V
Temperature
Operating temperature: -10°C ～+55°C
Storage temperature: -40°C ～+85°C
Physical
characteristics
Interface: M.2 Key-B
Dimension: 30 x 42 x 2.3mm
Weight: About 5.4 g
Interface
Antenna
WWAN Main Antenna x 1
WWAN Diversity Antenna(GNSS) x 1
Function Interface
USIM 3V/1.8V
USB 2.0 x 1
I2S(Reserved)
I2C
EINT、System Indicator
Clock(Reserved)

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Software
Protocol Stack
IPV4/IPV6
AT commands
3GPP TS 27.007 and 27.005, and proprietary FIBOCOM AT commands
Firmware update
USB
2.3 Application Framework
The peripheral applications for L831-EAU module are shown in Figure 2-1:
Figure2-1 Application Framework

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2.4 Hardware Framework
The hardware framework in Figure 2-2 shows the main hardware functions of L831-EAU module,
including base band and RF functions.
Baseband contains the followings:
UMTS/LTE FDD controller/Power supply
NAND/Micron LPDDR2 RAM
Application interface
RF contains the followings:
RF Transceiver
RF Power/PA
RF Front end
RF Filter
GNSS
Antenna
Figure 2-2 Hardware Framework
3 Application Interface
3.1 M.2 Interface
The L831-EAU module applies standard M.2 Key-B interface, with a total of 75 pins.

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3.1.1 Pin Distribution
Figure 3-1 Pin Distribution

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Note:
Pin “Notch” represents the gap of the gold fingers.
3.1.2 Pin Definition
The pin definition is as follows:
Pin
Pin Name
I/O
Reset
Value
Pin Description
Type
1
CONFIG_3
O
L
Connected to internal GND
2
+3.3V
PI
Module main power input
Power Supply
3
GND
GND
Power Supply
4
+3.3V
PI
Module main power input
Power Supply
5
GND
GND
Power Supply
6
FULL_CARD_POWER_OFF#
I
WWAN M.2 Power on/off control
signal
CMOS 1.8V
7
USB D+
I/O
USB 2.0 D+ signal
0.3---3V
8
W_DISABLE#
I
PU
WWAN M.2 RF Disable signal
3.3V/1.8V
9
USB D-
I/O
USB 2.0 D- signal
0.3---3V
10
LED#1
O
OD
System status LED, drain output
CMOS 3.3V
11
GND
GND
Power Supply
12
Notch
Notch
13
Notch
Notch
14
Notch
Notch
15
Notch
Notch
16
Notch
Notch
17
Notch
Notch
18
Notch
Notch
19
Notch
Notch
20
I2S_CLK
O
PD
I2S serial clock（Reserved）
CMOS 1.8V
21
CONFIG_0
O
Not connected

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Pin
Pin Name
I/O
Reset
Value
Pin Description
Type
22
I2S_RX
I
PD
I2S serial data input（Reserved）
CMOS 1.8V
23
WAKE_WWAN#
O
PU
Wake up host signal（Reserved）
CMOS 1.8V
24
I2S_TX
O
PD
I2S serial data output（Reserved）
CMOS 1.8V
25
DPR
I
PU
Body SAR control signal（Reserved）
CMOS 1.8V
26
GNSS_DISABLE#
I
PU
GNSS Disable signal（Reserved）
CMOS 1.8V
27
GND
GND
Power Supply
28
I2S_WA
O
PD
I2S clock for left and right channels
（Reserved）
CMOS 1.8V
29
SSIC_RXN
I/O
USB SSIC transmit data minus
（Reserved）
30
UIM_RESET
O
PP
USIM reset signal
1.8V/3V
31
SSIC_RXP
I/O
USB SSIC transmit data plus
（Reserved）
32
UIM_CLK
O
PP
USIM clock signal
1.8V/3V
33
GND
GND
Power Supply
34
UIM_DATA
I/O
PU
USIM data signal
1.8V/3V
35
SSIC_TXN
I/O
USB SSIC receive data minus
（Reserved）
36
UIM_PWR
O
USIM power supply
1.8V/3V
37
SSIC_TXP
I/O
USB SSIC receive data plus
（Reserved）
38
NC
Not Connect
39
GND
GND
Power Supply
40
I2C_SCL
O
PU
I2C serial clock signal
CMOS 1.8V
41
NC
Not Connect
42
I2C_SDA
I/O
PU
I2C serial data signal
CMOS 1.8V
43
NC
Not Connect
44
I2C_IRQ
I
PU
GNSS interrupt input signal
CMOS 1.8V

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Pin
Pin Name
I/O
Reset
Value
Pin Description
Type
45
GND
GND
Power Supply
46
SYSCLK
O
L
26MHz clock output（Reserved）
1.8V
47
NC
Not Connect
48
TX_BLANKING
O
L
PA Blanking Signal（Reserved）
CMOS 1.8V
49
NC
Not Connect
50
NC
Not Connect
51
GND
GND
Power Supply
52
NC
Not Connect
53
NC
Not Connect
54
NC
Not Connect
55
NC
Not Connect
56
NC
Not Connect
57
GND
GND
Power Supply
58
NC
Not Connect
59
ANTCTL0
O
L
Tunable antenna control signal
（Reserved）
CMOS 1.8V
60
COEX3
O
WWAN and WIFI/BT module
coexistence hardware
synchronization signal（Reserved）
61
ANTCTL1
O
L
Tunable antenna control signal
（Reserved）
CMOS 1.8V
62
COEX2
O
WWAN and WIFI/BT module
coexistence hardware
synchronization signal（Reserved）
63
ANTCTL2
O
L
Tunable antenna control signal
(Reserved)
CMOS 1.8V
64
COEX1
O
WWAN and WIFI/BT module
coexistence hardware
synchronization signal（Reserved）

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Pin
Pin Name
I/O
Reset
Value
Pin Description
Type
65
ANTCTL3
O
Tunable antenna control signal
（Reserved）
CMOS 1.8V
66
SIM_DETECT
I
SIM card detect
CMOS 1.8V
67
RESET#
I
Reset WWAN control signal
CMOS 1.8V
68
NC
Not Connect
69
CONFIG_1
O
L
Connected to internal GND
70
+3.3V
PI
Module main power input
Power Supply
71
GND
GND
Power Supply
72
+3.3V
PI
Module main power input
Power Supply
73
GND
GND
Power Supply
74
+3.3V
PI
Module main power input
Power Supply
75
CONFIG_2
O
L
Connected to internal GND
H: High Voltage Level
L: Low Voltage Level
PD: Pull-Down
PU: Pull-Up
T: Tristate
OD: Open Drain
PP: Push-Pull
PI: Power Input
PO: Power Output
Note:
The unused pins can be left floating.

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3.2 Power Supply
The power interface of L831-EAU module as shown in the following table:
Pin
Pin Name
I/O
Pin Description
DC Parameter（V）
Minimum
Value
Typical
Value
Maximum
Value
2,4,70,72,74
+3.3V
PI
Power supply input
3.135
3.3
4.4
36
UIM_PWR
PO
USIM power supply
1.8V/3V
3.2.1 Power Supply
The L831-EAU module should be powered through the +3.3V pins, and the power supply design is shown
in Figure 3-2:
Figure 3-2 Power Supply Design

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The filter capacitor design for power supply as shown in the following table:
Recommended
capacitance
Application
Description
220uF
Voltage-stabilizing
capacitors
Reduce power fluctuations of the module in
operation, requiring capacitors with low ESR.
LDO or DC/DC power supply requires the
capacitor of no less than 220uF
The capacitor for battery power supply can be
reduced to 100uF
1uF,100nF
Digital signal noise
Filter out the interference generated from the clock
and digital signals
39pF
900 MHz frequency band
Filter out low frequency band RF interference
18pF,8.2pF,6.8pF
1800/1900,2100/2300,2500
/2600MHz frequency band
Filter out medium/high frequency band RF
interference
The stable power supply can ensure the normal operation of L831-EAU module; and the ripple of the
power supply should be less than 300mV in design. When the module operates under maximum
transmitted power, the maximum operating current can reach 750mA, so the power source should be not
lower than 3.0V, or the module may shut down or reboot.
3.2.2 Logic level
The L831-EAU module 1.8V logic level definition as shown in the following table:
Parameters
Minimum
Typical
Maximum
Unit
1.8V logic level
1.71
1.8
1.89
V
VIH
1.3
1.8
1.89
V
VIL
-0.3
0
0.5
V
The L831-EAU module 3.3V logic level definition as shown in the following table:
Parameters
Minimum
Typical
Maximum
Unit
3.3V logic level
3.135
3.3
3.465
V
VIH
2.3
3.3
3.465
V
VIL
-0.3
0
0.9
V

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3.2.3 Power Consumption
In the condition of 3.3V power supply, the L831-EAU power consumption as shown in the following table
Parameter
Mode
Condition
Average
Typical
Current(mA)
Ioff
Power off
Power supply,module power off
0.08
ISleep
WCDMA
DRX=6
4.8
DRX=8
4.1
DRX=9
4.0
LTE FDD
Paging cycle #256 frames (2.56 sec DRX cycle)
3.8
Radio Off
AT+CFUN=4,Flight mode
2.0
IWCDMA-RMS
WCDMA
WCDMA Data transfer Band I @+23.5dBm
625
WCDMA Data transfer Band VIII @+23.5dBm
600
ILTE-RMS
LTE FDD
LTE FDD Data transfer Band 1 @+23dBm
630
LTE FDD Data transfer Band 3 @+23dBm
675
LTE FDD Data transfer Band 7 @+23dBm
715
LTE FDD Data transfer Band 8 @+23dBm
680
LTE FDD Data transfer Band 20 @+23dBm
640
LTE FDD Data transfer Band 28 @+23dBm
700
3.3 Control Signal
The L831-EAU module provides two control signals for power on/off and reset operations, the pin defined
as shown in the following table:
Pin
Pin Name
I/O
Reset Value
Functions
Type
6
FULL_CARD_POW
ER_OFF#
I
Power on/off signal, internal 150KΩ
pull-down.
High: Power on
Low or floating: Power off
1.8V/3.3V
67
RESET#
I
Reset signal, internal 100KΩ pull-up,
active low.
1.8V

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3.3.1 Module Start-Up
3.3.1.1 Start-up Circuit
By pulling up 1.8V/3.3V voltage externally, the module power-on pin FULL_CARD_POWER_OFF# can
power on, while the pull-up voltage VDD (1.8V/3.3V) is provided externally. The module provides two
power-on modes:
AP (Application Processor) controls 3.3V power module for powering on, the recommended circuit
design is shown in Figure 3-3:
Battery-powered, AP controls FULL_CARD_POWER_OFF# module for powering on, the
recommended circuit design is shown in Figure 3-4:
Figure 3-3 Power-on Circuit of AP Controlling 3.3V Power Module
Figure 3- 4 Power-on Circuit of AP Controlling FULL_CARD_POWER_OFF# Module

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3.3.1.2 Start-up Timing Sequence
For the above two different power-on circuits, there are the following two power-on timings after the
module powered on:
AP (Application Processor) controls 3.3V power module for powering on, the power-on timing is
shown in Figure 3-5:
Battery-powered, AP controls FULL_CARD_POWER_OFF# module for powering on, the power-on
timing is shown in Figure 3-6:
Figure 3-5 Power-on Timing Diagram of AP Controlling the Power
Figure 3-6 Power-on Timing Diagram of AP Controlling FULL_CARD_POWER_OFF#
Note:
When AP controls FULL_CARD_POWER_OFF# for powering on, RESET# shall be pulled up at
least 1ms in advance.
3.3.2 Module Shutdown
The module can be shut down by software or hardware control:
Shutdown Control
Action
Condition
Software
Sending AT+CPWROFF command
Normal shutdown.
Hardware
AP controlling 3.3V power module for
powering off
AP controlling FULL_CARD_POWER_OFF#
for powering off (battery-powered)
Only used when a hardware
exception occurs and the software
control cannot be used

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3.3.2.1 Software Shutdown
When the module receives the software shutdown command (AT+CPWROFF), the module will start the
finalization process (the reverse process of initialization), and it will be completed after 3s. In the
finalization process, the module will save the network, SIM card and some other parameters from memory,
then clear the memory and PMU will be powered off. After shutdown, the VSD2_1V8 voltage is also shut
down. The software control timing is shown in Figure 3-7:
Figure 3-7 Software Shutdown Timing Control
After the software shutdown, the FUL_CARD_POWER_OFF # pin will remain high which prevents the
module from restarting again. To enable the next restart, the FUL_CARD_POWER_OFF# pin should be
pulled low after shutting down more than 500ms (recommended1000ms).
Note:
The VSD2_1V8 signal is the internal PMU 1.8V output voltage which is not connected to the M.2
interface. The above timing of VSD2_1V8 is only for reference.
3.3.2.2 Hardware Shutdown
By pulling down RESET for 1ms first and then FULL_CARD_POWER_OFF# (or controlling M.2 3.3V
power by GPIO) for more than 500ms (1,000 ms recommended), the Power Management Unit (PMU) of
the module loses its power, and then the module will shut down by hardware. As the PMU of the module
loses its power when FULL_CARD_POWER_OFF# is pulled down, the module may be damaged after
repeated reboots.
The power-off timing diagram of hardware controlling 3.3V power is shown in Figure 3-8;
The power-off timing diagram of hardware controlling FULL_CARD_POWER_OFF# is shown in
Figure 3-9;