Telit Wireless Solutions LE915A P Series User manual

[01.2017]
Mod. 0805 2017-01 Rev.6
LE915Ax-P
HW User Guide
1VV0301680 Rev.0 –2020-09-16

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SPECIFICATIONS ARE SUBJECT TO CHANGE WITHOUT NOTICE
NOTICE
While reasonable efforts have been made to assure the accuracy of this document, Telit
assumes no liability resulting from any inaccuracies or omissions in this document, or from
use of the information obtained herein. The information in this document has been carefully
checked and is believed to be reliable. However, no responsibility is assumed for
inaccuracies or omissions. Telit reserves the right to make changes to any products
described herein and reserves the right to revise this document and to make changes from
time to time in content hereof with no obligationto notify any person of revisions or changes.
Telit does not assume any liability arising out of the application or use of any product,
software, or circuit described herein; neither does it convey license under its patent rights
or the rights of others.
It is possible that this publication may contain references to, or information about Telit
products (machines and programs), programming, or services that are not announced in
your country. Such references or information must not be construed to mean that Telit
intends to announce such Telit products, programming, or services in your country.
COPYRIGHTS
This instruction manual and the Telit products described in this instruction manual may be,
include or describe copyrighted Telit material, such as computer programs stored in
semiconductor memories or other media. Laws in the Italy and other countries preserve for
Telit and its licensors certain exclusive rights for copyrighted material, including the
exclusive right to copy, reproduce in any form, distribute and make derivative works of the
copyrighted material. Accordingly, any copyrighted material of Telit and its licensors
contained herein or in the Telit products described in this instruction manual may not be
copied, reproduced, distributed, merged or modified in any manner without the express
written permission of Telit. Furthermore, the purchase of Telit products shall not be deemed
to grant either directly or by implication, estoppel, or otherwise, any license under the
copyrights, patents or patent applications of Telit, as arises by operation of law in the sale
of a product.
COMPUTER SOFTWARE COPYRIGHTS
The Telit and 3rd Party supplied Software (SW) products described in this instruction
manual may include copyrighted Telit and other 3rd Party supplied computer programs
stored in semiconductor memories or other media. Laws in the Italy and other countries
preserve for Telit and other 3rd Party supplied SW certain exclusive rights for copyrighted
computer programs, including the exclusive right to copy or reproduce in any form the
copyrighted computer program. Accordingly, any copyrighted Telit or other 3rd Party
supplied SW computer programs contained in the Telit products described in this instruction
manual may not be copied (reverse engineered) or reproduced in any manner without the
express written permission of Telit or the 3rd Party SW supplier. Furthermore, the purchase
of Telit products shall not be deemed to grant either directly or by implication, estoppel, or
otherwise, any license under the copyrights, patents or patent applications of Telit or other
3rd Party supplied SW, except for the normal non-exclusive, royalty free license to use that
arises by operation of law in the sale of a product.

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USAGE AND DISCLOSURE RESTRICTIONS
I. License Agreements
The software described in this document is the property of Telit and its licensors. It is
furnished by express license agreement only and may be used only in accordance with the
terms of such an agreement.
II. Copyrighted Materials
Software and documentation are copyrighted materials. Making unauthorized copies is
prohibited by law. No part of the software or documentation may be reproduced,
transmitted, transcribed, stored in a retrieval system, or translated into any language or
computer language, in any form or by any means, without prior written permission of Telit
III. High Risk Materials
Components, units, or third-party products used in the product described herein are NOT
fault-tolerant and are NOT designed, manufactured, or intended for use as on-line control
equipment in the following hazardous environments requiring fail-safe controls: the
operation of Nuclear Facilities, Aircraft Navigation or Aircraft Communication Systems, Air
Traffic Control, Life Support, or Weapons Systems (High Risk Activities"). Telit and its
supplier(s) specifically disclaim any expressed or implied warranty of fitness for such High-
Risk Activities.
IV. Trademarks
TELIT and the Stylized T Logo are registered in Trademark Office. All other product or
service names are the property of their respective owners.
V. Third Party Rights
The software may include Third Party Right software. In this case you agree to comply with
all terms and conditions imposed on you in respect of such separate software. In addition
to Third Party Terms, the disclaimer of warranty and limitation of liability provisions in this
License shall apply to the Third-Party Right software.
TELIT HEREBY DISCLAIMS ANY AND ALL WARRANTIES EXPRESS OR IMPLIED
FROM ANY THIRD PARTIES REGARDING ANY SEPARATE FILES, ANY THIRD PARTY
MATERIALS INCLUDED IN THE SOFTWARE, ANY THIRD PARTY MATERIALS FROM
WHICH THE SOFTWARE IS DERIVED (COLLECTIVELY “OTHER CODE”), AND THE
USE OF ANY OR ALL THE OTHER CODE IN CONNECTION WITH THE SOFTWARE,
INCLUDING (WITHOUT LIMITATION) ANY WARRANTIES OF SATISFACTORY
QUALITY OR FITNESS FOR A PARTICULAR PURPOSE.
NO THIRD PARTY LICENSORS OF OTHER CODE SHALL HAVE ANY LIABILITY FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING WITHOUT LIMITATION LOST PROFITS), HOWEVER CAUSED
AND WHETHER MADE UNDER CONTRACT, TORT OR OTHER LEGAL THEORY,
ARISING IN ANY WAY OUT OF THE USE OR DISTRIBUTION OF THE OTHER CODE
OR THE EXERCISE OF ANY RIGHTS GRANTED UNDER EITHER OR BOTH THIS
LICENSE AND THE LEGAL TERMS APPLICABLE TO ANY SEPARATE FILES, EVEN IF
ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

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APPLICABILITY TABLE
PRODUCTS
LE915A6-P
LE915A4-P

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CONTENTS
1. INTRODUCTION............................................................................................7
Scope.............................................................................................................7
Audience.........................................................................................................7
Contact Information, Support..........................................................................7
Text Conventions............................................................................................8
Related Documents........................................................................................8
2. GENERAL PRODUCT DESCRIPTION ..........................................................9
Main features..................................................................................................9
Cellular Frequency bands and CA combinations.............................................9
2.2.1. Frequency bands.............................................................................................9
2.2.2. Carrier Aggregation (LE915A6-P only)...........................................................10
Target market...............................................................................................10
Block Diagram ..............................................................................................10
Pin Assignment.............................................................................................11
3. POWER SUPPLY.........................................................................................13
Power Supply Requirement ..........................................................................13
Power Consumption .....................................................................................13
1.8V power output.........................................................................................13
General Design Rules...................................................................................14
3.4.1. Electrical Design Guidelines ..........................................................................14
3.4.1.1. + 5V Input Source Power Supply –Design Guidelines...................................14
3.4.2. Thermal Design Guidelines............................................................................14
3.4.3. Power Supply PCB layout Guidelines............................................................14
3.4.4. PCB pad design.............................................................................................15
4. INTERFACE DETAILS.................................................................................16
Power and Ground........................................................................................16
Power On/Off and reset control.....................................................................16
4.2.1. Power on sequence.......................................................................................16
4.2.2. Power off sequence.......................................................................................17
USB 2.0 interface..........................................................................................17
UART interface.............................................................................................18
LED Indication..............................................................................................21
SIM interface ................................................................................................22
Reserved pads .............................................................................................23
5. ANTENNA INTERFACE AND RADIO PERFORMANCE .............................24

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Antenna ports...............................................................................................24
Antenna specification recommended............................................................24
Transmission line design guidelines..............................................................24
Antenna installation guidelines......................................................................25
RF performance............................................................................................26
5.5.1. RF power output............................................................................................26
5.5.2. RX Sensitivity ................................................................................................26
6. ENVIRONMENT REQUIREMENT................................................................27
Temperature range.......................................................................................27
7. MECHANICAL SPECIFICATIONS...............................................................28
Weight..........................................................................................................28
Dimension and pad numbering.....................................................................28
8. REFLOW INFORMATION............................................................................29
9. PACKAGING................................................................................................30
10. REGULATORY APPROVAL........................................................................32
11. SAFETY RECOMMENDATIONS..................................................................35
READ CAREFULLY......................................................................................35
12. ACRONYMS.................................................................................................36
13. DOCUMENT HISTORY................................................................................37

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1. INTRODUCTION
Scope
This document introduces the Telit LE915Ax-P family and presents possible and
recommended hardware solutions for developing a product based on the LE915Ax-P
modules.
In this document all the basic functions of the module will be considered; for each one of
them a proper hardware solution will be suggested and eventually the wrong solutions and
common errors to be avoided will be evidenced. Obviously, this document cannot embrace
the whole hardware solutions and products that may be designed. The wrong solutions to
be avoided shall be considered as mandatory, while the suggested hardware configurations
shall not be considered mandatory, instead the information given shall be used as a guide
and a starting point for properly developing your product with the Telit LE915Ax-P modules.
Information –Integration of the single mode LTE/CBRS LE915Ax-P
cellular modules within a user application must be performed
according to the design rules described in this manual.
The information presented in this document is believed to be accurate and reliable.
However, no responsibility is assumed by Telit Communications S.p.A. for its use, nor any
infringement of patents or other rights of third parties which may result from its use. No
license is granted by implication or otherwise under any patent rights of Telit
Communications S.p.A. other than for circuitry embodied in Telit products. This document
is subject to change without notice.
Audience
This document is intended for Telit customers, especially system integrators, about to
implement their applications using the Telit LE915Ax-P family.
Contact Information, Support
For general contact, technical support services, technical questions and report
documentation errors contact Telit Technical Support at:
•TS[email protected]
•[e-mail]
•[e-mail]
•[e-mail]
For detailed information about where you can buy the Telit modules or for recommendations
on accessories and components visit:
http://www.telit.com

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Our aim is to make this guide as helpful as possible. Keep us informed of your comments
and suggestions for improvements.
Telit appreciates feedback from the users of our information.
Text Conventions
Danger –This information MUST be followed, or catastrophic
equipment failure or bodily injury may occur.
Caution or Warning –Alerts the user to important points about
integrating the module, ifthese points are not followed, the module and
end user equipment may fail or malfunction.
Tip or Information –Provides advice and suggestions that may be
useful when integrating the module.
All dates are in ISO 8601 format, i.e. YYYY-MM-DD.
Related Documents
•LE915Ax-P family AT command reference guide, 80671STxxxxxA

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2. GENERAL PRODUCT DESCRIPTION
The LE915Ax-P family consists of an LTE CAT-6 and CAT-4 modules and is specifically
designed to enable cellular data connectivity on CBRS networks operating on TDD LTE
band 48 in US. It can also operate on other networks operating on LTE bands 42 and 43.
This document provides technical information about LE915Ax-P LCC modules.
Main features
Main features of the LE915Ax-P are listed below.
Table 2.1-1 LE915Ax-P Feature Summary
Feature
Description
Physical
LCC (32 x 29 x2.4mm),
134 pads carrying useful signals
Power supply
Nominal 3.8V single power supply
Operating voltage
recommended
-30 ~ +60 °C ambient
Serial interface
USB 2.0,
1 UART with HW flow control and 2 UART w/o flow control
Cellular technology
LE915A6-P: LTE CAT.6, TDD, 200Mbps on DL, 3GPP release 10
LE915A4-P: LTE CAT.4, TDD, 100Mbps on DL, 3GPP release 9
Diversity/2nd Rx
4G: all operating on all supported frequency bands
SIM interface
Single interface for 1.8V and 3.0V
Antenna ports
1 main and 1 auxiliary antenna ports
Cellular Frequency bands and CA combinations
2.2.1. Frequency bands
Following the list of operating frequencies on LTE mode.
Table 2.2.1-1 LTE Bands supportive
E-UTRA
BAND
Frequency
(MHz)
Uplink
Frequency
UE Receive
(MHz)
Downlink
Frequency
UE Receive
(MHz)
Duplex
Mode
42
3500
3400 - 3600
TDD
43
3700
3600 - 3800
TDD
48
3500
3550 –3700
TDD

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2.2.2. Carrier Aggregation (LE915A6-P only)
The following tables list the 2CC configurations available on LE915A6-P.
Table 2.2.2-1 Two Carrier Component Carrier Aggregation Configurations
Applicable model
2CC DL CA Combinations
LE915A6-P
CA_42A-42A; CA_43A-43A; CA_48A-48A; CA_42A-43A;
CA_42C; CA_43C; CA_48C
Target market
The LE915Ax-P family is specifically designed to enable cellular data connectivity on CBRS
networks operating on LTE band 48 in US. It can also operate on other networks operating
on LTE band 42 and 43.
It meets also the requirements for M2M application such as metering, tracking system,
security solutions, routers, wireless POS, among others.
Block Diagram
Figure 2.4-1 LE915A6-P block daigram
Figure 2.4-2 LE915A4-P block diagram

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Pin Assignment
The main function and basic description of the LCC pads are swacribed in the table below.
Table 2.5-1 Host Interface Summary
Pad#
Pad Name
I/O
Comments
2
ANT_DIV
I
Auxiliary antenna
4
ANT_MAIN
I/O
Main antenna
6
HWID2
I
1.8V, reserved
7
HWID1
I
1.8V, reserved
11
VBAT2
P
3.8V, Main power supply
12
VBAT2
P
3.8V, Main power supply
18
NETWORK_LED
O
DL status indication LED
21
UART0_SIN
I
1.8V, UART0
22
UART0_SOUT
O
1.8V, UART0
23
UART2_CTS
I
1.8V, UART2
24
UART2_RTS
O
1.8V, UART2
25
UART2_SIN
I
1.8V, UART2
26
UART2_SOUT
O
1.8V, UART2
56
USB_EXT_VBUS_VLD
I
1.8V, VUSB
57
USB_D+
I/O
3.3V, USB_D+
58
USB_D-
I/O
3.3V, USB_D-
59
VBAT1
P
3.8V, Main power supply
60
VBAT1
P
3.8V, power supply of PA
62
1V8_D
O
1.8V output
63
RESET_N
I
1.8V, reset control
64
MODULE_PWR_EN
I
1.8V, power on/off control
65
SIM_VCC
O
SIM power
66
SIM_RST
O
SIM reset
67
SIM_IO
I/O
SIM data I/O
68
SIM_CLK
O
SIM clock
69
SIM_DETECT
I
SIM detect input

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80
FFF_FFH
I
1.8V, reserved
119
UART1_SIN
I
1.8V, UART1
120
TRST_N
I
JTAG for debugging
121
TMS
I
JTAG for debugging
122
TDI
I
JTAG for debugging
131
UART1_SOUT
O
1.8V, UART1
133
TCK
I
JTAG for debugging
134
TDO
O
JTAG for debugging
Table 2.5-2 Ground Pads
Pad #
Pad Name
Comment
1, 3, 5, 10, 13, 29, 61
GND
81 to 110
GND
Table 2.5-3 Reserved Pads
Pad #
Pad Name
Comment
111 to 118,
123 to 130, 132
DNC
Do not connect.
8, 9, 14 to 17, 19, 20, 27, 28, 30 to 55,
70 to 79
Reserved
Reserved for later update.

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3. POWER SUPPLY
The power supply circuitry and board layout are very important factors of the entire
customer device design and could affect on the overall functionality and radio performance
of the end device.
Please refer to the following requirements and guidelines carefully to ensure device quality.
Power Supply Requirement
The LE915Ax-P power requirements of VBAT1 and VBAT2 are as follows:
Table 3.1-1 Power Supply Requirement
Nominal supply voltage
3.8V
Recommended voltage range
3.3V –4.4V
Maximum ripple on module input supply
30 mV
3.3V is the minimum operating voltage acceptable for LE915Ax-P. Special care must be
taken to prevent voltage drops below 3.3V even when transmission starts from idle state.
Applying a voltage monitoring circuit in the application board is highly recommended to
ensure the supply voltage is suitable for stable operating.
Power Consumption
Table 3.2-1 Typical current consumption
Test condition
LE915A6-P (mA)
LE915A4-P (mA)
Off current
TBD
TBD
LTE (Tx=0dBm)
1050
670
LTE (Tx=23dBm)
1410
1010
Information –The power supply should be dimensioned for at least
2.0A at nominal power supply voltage.
1.8V power output
The pad 1V8_D is the reference voltage output for IOs. It can be used to provide power
to small devices up to 50mA max.
Pin#
Pin Name
I/O
Min
Typical
Max
62
1V8_D
O
1.71V
1.8V
1.89V

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General Design Rules
The principal guidelines for the Power Supply Design embrace three different design steps:
•Electrical design
•Thermal design
•PCB layout
3.4.1. Electrical Design Guidelines
The electricaldesign of the power supplystrongly depends onthe powersource fromwhich
power is drained.
3.4.1.1. + 5V Input Source Power Supply –Design Guidelines
•The desired output for the power supply is 3.8V. Being the difference between the
input source and the desired output moderate, a linear regulator can be used. A
switching power supply is preferred to reduce power consumption.
•When using a linear regulator, a proper heat sink must be provided to dissipate the
heat generated.
•A bypass low ESR capacitor of adequate capacity must be provided to cut the
current absorption peaksclose to the powersupply pin of the Telit module. Reserve
some higher value of capacitors in a few 100uF on the 3.8V input of the module.
•Make sure that the low ESR capacitors on the power supply output (usually a
tantalum one) is rated at least 10V.
•A protection diode must be inserted close to the power input to protect Telit module
from power polarity inversion and/or EOS.
3.4.2. Thermal Design Guidelines
Thermal dispersion needs to be carefully considered in entire customer device design. The
power supply heat sink must be dimensioned according to the following guidelines:
•Opening a large ground plane as wider as Telit module size and to add a thermal
interface material tightly touched between the bottom side of Telit module and the
customer board is a mandatory.
•Adding a heat sink on top of the shield cover with a thermal interface material and
making an air flow mechanism for cooling down the heat is also highly
recommended.
•Applying a cooling down system in the customer application design is much better
as an option.
•The body of the Telit module must be connected to the ground plane and/or metal
chassis of the host board for better radio performance and thermal dissipation.
3.4.3. Power Supply PCB layout Guidelines
As described in the electrical design guidelines, the power supply must have some low
ESR capacitors close to the input port of the Telit module to cut current peaks and a
protection diode on the input to prevent from electrical shock and/or polarity inversion.
•Some bypass low ESR capacitors must be placed close to the power input pins or
the Telit module. The location of these components is crucial to effective operation
of the circuitry: a misplaced component can be useless or can even decrease the

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power supply performances. If the power supply used is a switching type - it can
be placed close to an inductor to reduce a noise and ripple.
•A protection diode must be placed close to the power input port of the module to
prevent from any electrical shock and/or polarity inversion.
•The PCB traces on the entire power supply circuits including bypass capacitors
must be wide enough to ensure that no significant voltage drops are occurred when
the maximum current peaks are absorbed. These traces also should be kept as
short as possible.
•The PCB traces connecting the switching output to the inductor and the switching
diode must be kept as short as possible by placing the inductor and the diode very
close to the power switching IC (only for the switching power supply). This is done
to reduce the radiated field (noise) at the switching frequency (usually 100-
500 kHz).
•Use a good common ground plane.
•Place a power supply circuits on the board in a way to guarantee that the high
current return pathsin the ground plane do not overlap any noise sensitivecircuitry,
such as an antenna connection path or analog/audio interface.
•The power supply input cables must be kept separate from noise sensitive lines,
such as an antenna connection path or analog/audio interface.
3.4.4. PCB pad design
Non solder mask defined (NSMD) type is recommended for the solder pads on the PCB.

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4. INTERFACE DETAILS
Power and Ground
All the power supply pads, and ground should be connected.
Pin#
Pin Name
I/O
Comment
59, 60
VBAT1
P
All VBAT pads shall be connected.
11, 12
VBAT2
P
1, 3, 5, 10, 13, 29, 61
GND
G
All GND pads shall be connected to the
same copper.
81 to 110
GND
G
All GND pads shall be connected to the
same copper. Those pads have a
thermal dissipation function too.
Power On/Off and reset control
The Telit module can be turned on/off by means of the MODULE_PWR_EN port.
The module enters Power on Reset mode when the RESET_N is set logical LOW.
While the device power-on sequence is still in progress, the two conditions below must be
avoided:
•The main power supplyvoltage shall not be drop below minimum operating voltage.
•None of the two pins (MODULE_PWR_EN, RESET_N) can transition to LOW.
Pin#
Pin Name
I/O
Function description
64
MODULE_PWR_EN
I
Active HIGH to power on.
63
RESET_N
I
Active LOW for reset while
MODULE_PWR_EN is high in normal
operating mode.
This signal should be pulled by 100kohms
to 1.8V.
The minimum hold time for reset is 1uS.
4.2.1. Power on sequence
The power supply should be stable enough before releasing the MODULE_PWR_EN to
HIGH to turn the module.
Step 1: Supply VBAT1 and VBAT2.
Step 2: Wait until the VBAT1 and VBAT2 power supply are stable enough as over than
3.3V minimum operating voltage.
Step 3: Set RESET_N port to HIGH

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Step 4: Wait until communicating on AT command is possible or until the +SYSSTART
URC is out. Which is typically in the range of 30 ~ 60 seconds in normal operating mode.
If there is no response over than 60 Sec, turn off the VBAT1 and VBAT2 to make it zero
voltage, then try again from the step 1.
4.2.2. Power off sequence
In order to safely power off the module, it is recommended to wait at least 10 seconds after
sending the AT+SQNSSHDN shutdown command before turning off VBAT1/2.
USB 2.0 interface
The USB controller of LE915Ax-P is compliant with USB 2.0. PCB routes must be designed
so that USB lines are 90 Ohm differential.
Pin#
Pin Name
I/O
Function description
56
USB_EXT_VBUS_VLD
I
1.8V logical input to detect VBUS.
57
USB_D+
I/O
USB 2.0 plus, differential
58
USB_D-
I/O
USB 2.0 minus, differential
The filter is used to provide high impedance to higher frequency components of the USB
signals and helps reducing potential RF noise coming from USB lines. D+ and D- signals
are sensitive to track design, please refer to the following interface example.
WARNING:
Maximum input voltage range of USB_EXT_VBUS_VLD is up to 3.6V.
It is required to have a non-inverting level shifter or voltage divider to
connect this port to an external 5.1V VBUS.

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Figure 4.3-1 example of USB interface
NOTE:
On the application board. It is highly recommended to insert an
optional connector or test points that can be switched for direct
connection of the external PC for later SW upgrade or debugging.
UART interface
The LE915Ax-P supports one UART with HW flow control and two UARTs without flow
control.
Pin#
Pin Name
I/O
Function description
25
UART2_SIN
I
Serial data input (TXD) from DTE
26
UART2_SOUT
O
Serial data output (RXD) to DTE
23
UART2_CTS
I
Input for Request to send(RTS) from DTE
24
UART2_RTS
O
Output for Clear so send(CTS) to DTE
21
UART0_SIN
I
UART0 w/o flow control
22
UART0_SOUT
O
119
UART1_SIN
I
UART1 w/o flow control
131
UART1_SOUT
O

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NOTE:
When the UART signals are used as the communication port between
the host and modem and flow control is not used, UART2_CTS line
must set to logical LOW. If the UART port is not used, all UART signals
can be left unconnected.
NOTE:
To prevent reverse-powering effect, it isrecommended to avoid having
any HIGH logic level signal applied to the digital pins of the module
when it is powered OFF or during an ON/OFF transition.
Figure 4.4-1 Typical UART interface with HW flow control

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Figure 4.4-2 Typical UART interface without HW flow control
Depending on the serial port type on the application side, a level translator circuit may be
required. The nominal voltage level of the UART interface is 1.8V.
Figure 4.4-3 shows a typical level translator circuit for interfacing the external device with
UART ports.