Telit ML865C1 User Manual
ML865C1
HW User Guide
1VV0301493 Rev. 4 – 2020-07-27
1.2017]
Mod. 0805 2017-01 Rev.6
ML865C1 HW User Guide
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 obligation to 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
ML865C1-NA
ML865C1-EA
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Contents
NOTICE 2
COPYRIGHTS ................................................................................................ 2
COMPUTER SOFTWARE COPYRIGHTS ...................................................... 2
USAGE AND DISCLOSURE RESTRICTIONS ............................................... 3
I. License Agreements ..................................................................... 3
II. Copyrighted Materials ................................................................... 3
III. High Risk Materials ....................................................................... 3
IV. Trademarks .................................................................................. 3
V. Third Party Rights ......................................................................... 3
APPLICABILITY TABLE ................................................................................ 4
CONTENTS .................................................................................................... 5
1. INTRODUCTION .......................................................................... 9
Scope ........................................................................................... 9
Audience....................................................................................... 9
Contact Information, Support ........................................................ 9
Text Conventions ........................................................................ 10
Related Documents .................................................................... 11
2. OVERVIEW ................................................................................ 12
3. PINS ALLOCATION ................................................................... 14
Pin-out ........................................................................................ 14
Pin Layout ................................................................................... 19
4. POWER SUPPLY ....................................................................... 20
Power Supply Requirements ....................................................... 20
Power Consumption ................................................................... 21
4.2.1. Current consumption plots .......................................................... 22
General Design Rules ................................................................. 24
4.3.1. Electrical Design Guidelines ....................................................... 24
4.3.1.1. +5V Source Power Supply Design Guidelines ............................ 24
4.3.1.2. +12V Source Power Supply Design Guidelines .......................... 25
4.3.1.3. Battery Source Power Supply Design Guidelines ........................ 26
4.3.2. Thermal Design Guidelines ......................................................... 28
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4.3.3. Power Supply PCB layout Guidelines ......................................... 29
RTC supply ................................................................................. 30
VAUX Power Output ................................................................... 31
5. DIGITAL SECTION .................................................................... 32
Logic Levels ................................................................................ 32
Power On (Auto-Turning ON ML865) .......................................... 32
Power Off.................................................................................... 36
Wake from deep sleep mode ...................................................... 36
Unconditional Shutdown ( Hardware Unconditional restart) ........ 38
Fast power down ........................................................................ 41
5.6.1. Fast Shut Down by Hardware ..................................................... 41
5.6.2. Fast Shut Down by Software....................................................... 42
Communication ports .................................................................. 42
5.7.1. USB 2.0 HS ................................................................................ 42
5.7.2. SPI.............................................................................................. 44
5.7.3. Serial Ports ................................................................................. 45
5.7.3.1. Modem serial port 1 .................................................................... 45
5.7.3.2. Modem serial port 2 .................................................................... 47
5.7.3.3. RS232 level translation ............................................................... 48
General purpose I/O ................................................................... 49
5.8.1. Using a GPIO as INPUT ............................................................. 50
5.8.2. Using a GPIO as OUTPUT ......................................................... 51
5.8.3. Indication of network service availability ..................................... 51
External SIM Holder .................................................................... 52
ADC Converter ........................................................................... 52
6. RF SECTION .............................................................................. 54
Bands Variants ........................................................................... 54
TX Output power ......................................................................... 54
RX Sensitivity ............................................................................. 54
Antenna requirements................................................................. 56
6.4.1. PCB Design guidelines ............................................................... 57
6.4.2. PCB Guidelines in case of FCC Certification .............................. 59
6.4.2.1. Transmission line design ............................................................ 59
6.4.2.2. Transmission Line Measurements .............................................. 61
6.4.2.3. Antenna Installation Guidelines ................................................... 63
7. AUDIO SECTION ....................................................................... 64
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Electrical Characteristics ............................................................. 64
Codec examples ......................................................................... 64
8. GNSS SECTION ......................................................................... 65
GNSS Signals Pin-out................................................................. 65
RF Front End Design .................................................................. 65
8.2.1. Guidelines of PCB line for GNSS Antenna .................................. 65
GNSS Antenna Requirements .................................................... 65
8.3.1. GNSS Antenna specification ....................................................... 66
8.3.2. GNSS Antenna – Installation Guidelines ..................................... 66
8.3.3. Powering the External LNA (active antenna) ............................... 66
GNSS Characteristics * ............................................................... 67
9. MECHANICAL DESIGN ............................................................. 68
Drawing ...................................................................................... 68
10. APPLICATION PCB DESIGN .................................................... 69
General ....................................................................................... 69
Footprint ..................................................................................... 69
PCB pad design .......................................................................... 71
PCB pad dimensions .................................................................. 71
Stencil ......................................................................................... 72
Solder paste ............................................................................... 73
Solder Reflow ............................................................................. 73
11. PACKAGING .............................................................................. 75
Tray ............................................................................................ 75
Reel ............................................................................................ 77
Moisture sensitivity ..................................................................... 77
12. CONFORMITY ASSESSMENT ISSUES .................................... 79
Approvals.................................................................................... 79
FCC certificates .......................................................................... 79
IC/ISED certificates ..................................................................... 79
FCC/ISED Regulatory notices ..................................................... 79
Declaration of Conformity ........................................................... 84
ANATEL Regulatory Notices ....................................................... 84
13. SAFETY RECOMMENDATIONS................................................ 85
READ CAREFULLY .................................................................... 85
14. ACRONYMS ............................................................................... 86
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15. DOCUMENT HISTORY .............................................................. 88
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1. INTRODUCTION
Scope
Scope of this document is is the description of some hardware solutions useful for
developing a product with the Telit ML865C1 module.
Audience
This document is intended for Telit customers, who are integrators, about to implement their
application using our ML865C1 module.
Contact Information, Support
For general contact, technical support services, technical questions and report
documentation errors contact Telit Technical Support at:
TS-EMEA@telit.com
TS-AMERICAS@telit.com
TS-APAC@telit.com
TS-SRD@telit.com
Alternatively, use:
http://www.telit.com/support
For detailed information about where you can buy the Telit modules or for recommendations
on accessories and components visit:
http://www.telit.com
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.
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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, if these 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.
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Related Documents
80000NT10001A - SIM INTEGRATION DESIGN GUIDES Application Note
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2. OVERVIEW
The aim of this document is the description of some hardware solutions useful for
developing a product with the Telit ML865C1 module. In this document all the basic
functions of a mobile phone will be taken into account; 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 ML865C1 module. For
further hardware details that may not be explained in this document refer to the Telit
ML865C1 Product Description document where all the hardware information is reported.
NOTE:
(EN) The integration of the ML865C1 cellular module within user
application shall be done according to the design rules described in
this manual.
(IT) L’integrazione del modulo cellulare ML865C1 all’interno
dell’applicazione dell’utente dovrà rispettare le indicazioni progettuali
descritte in questo manuale.
(DE) Die Integration des ML865C1 Mobilfunk-Moduls in ein Gerät
muß gemäß der in diesem Dokument beschriebenen
Kunstruktionsregeln erfolgen.
(SL) Integracija ML865C1 modula v uporabniški aplikaciji bo morala
upoštevati projektna navodila, opisana v tem priročniku.
(SP) La utilización del modulo ML865C1 debe ser conforme a los
usos para los cuales ha sido deseñado descritos en este manual del
usuario.
(FR) L’intégration du module cellulaire ML865C1 dans l’application de
l’utilisateur sera faite selon les règles de conception décrites dans ce
manuel.
(HE)
LE910 V2
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
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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.
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3. PINS ALLOCATION
Warning: ML865C1 is adopting a modified 56-pin xL865 Form Factor,
pin to pin compatible with the previous 48-pin xL865 FF and with 8
additional pads.
The numbering of the pins has been changed accordingly and
attention has to be paid when comparing with previous 48-pin xL865
FF design.
Pin-out
Pin Signal I/
Function Type Comment
O
USB HS 2.0 COMMUNICATION PORT
20 USB_D+ I/O USB differential Data
(+)
19 USB_D- I/O USB differential Data
(-)
18 VUSB I Power sense for the
internal USB
transceiver.
Asynchronous Serial Port (USIF0) - Prog. / Data + HW Flow Control
1 C109/DCD/GPO O Output for Data carrier
detect signal (DCD) to
DTE
3V
3V
3-5V Internal PD
CMOS
1.8V
(100K)
/ GP output
2 C125/RING/GPO O Output for Ring
indicator signal (RI) to
DTE
/ GP output
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CMOS
1.8V
ML865C1 HW User Guide
3 C107/DSR/GPO O Output for Data set
ready signal (DSR) to
DTE
/ GP output
4 C108/DTR/GPI I Input for Data terminal
ready signal (DTR)
from DTE
/ GP input
5 C105/RTS/GPI I Input for Request to
send signal (RTS)
from DTE
/ GP input
6 C106/CTS/GPO O Output for Clear to
send signal (CTS) to
DTE
/ GP output
CMOS
1.8V
CMOS
1.8V
CMOS
1.8V
CMOS
1.8V
9 C103/TXD I Serial data input
(TXD) from DTE
10 C104/RXD O Serial data output to
DTE
SIM card interface
11 SIMVCC - External SIM signal –
Power supply for the
SIM
12 SIMRST O External SIM signal –
Reset
13 SIMCLK O External SIM signal –
Clock
14 SIMIO I/O External SIM signal –
Data I/O
CMOS
1.8V
CMOS
1.8V
1,8 / 3V
1,8 / 3V
1,8 / 3V
47k Pull
up
1,8 / 3V
ADC
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15 ADC_IN1 I Analog/Digital
converter input
Auxiliary
52 RXD_AUX /SPI_MISO I Auxiliary UART (RX
Data)/SPI_MISO
53 TXD_AUX / SPI_MOSI O Auxiliary UART (TX
Data)/SPI_MOSI
Miscellaneous
7 WAKE I ASYNCRONOUS
WAKEUP FROM PSM
55 HW_SHUTDOWN* I UNCONDITIONAL
SHUTDOWN
CMOS 1.8V
CMOS 1.8V
1.8V
1.8V
51 V_AUX/PWRMON O 1.8V
56 FORCED_USB_BOOT I 1.8V
40 ANTENNA I/O Antenna pad – 50 Ω RF
37 GNSS_ANT I/O GNSS receiver input -
RF
50 Ω
GPIO
48 GPIO_01 / DVI_WA0 I/O GPIO01 Configurable
CMOS 1.8V
GPIO / Digital Audio
Interface (WA0)
47 GPIO_02 /DVI_RX I/O GPIO02 I/O pin
CMOS 1.8V
Digital Audio Interface
(RX)
46 GPIO_03 / DVI_TX I/O GPIO03 GPIO I/O pin/
CMOS 1.8V
Digital Audio Interface
(TX)
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45 GPIO_04 / DVI_CLK I/O GPIO04 Configurable
CMOS 1.8V
GPIO/ Digital Audio
Interface (CLK)
33 GPIO_05/
GNSS_LNA_EN
32 GPIO_06 / SPI_CS I/O GPIO06 Configurable
I/O GPIO05 Configurable
GPIO
CMOS 1.8V
CMOS 1.8V
GPIO /SPI_CS
31 GPIO_07 I/O GPIO07 Configurable
CMOS 1.8V
GPIO
30 GPIO_08 I/O GPIO08 Configurable
CMOS 1.8V
GPIO
29 SPI_CLK O SPI_CLK CMOS 1.8V
X STAT_LED O STAT_LED CMOS
1.8V
All 8 GPIO
pins can be
configured
Power Supply
44 VBATT - Main power supply
Power
(Baseband)
43 VBATT_PA - Main power supply
Power
(Radio PA)
42 GND - Ground Power
41 GND - Ground Power
39 GND - Ground Power
38 GND - Ground Power
35 GND - Ground Power
27 GND - Ground Power
23 GND - Ground Power
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21 GND - Ground Power
54 GND - Ground Power
Reserved
8 RFU
15 RFU
16 RFU
17 RFU
22 RFU
24 RFU
25 RFU
26 RFU
28 RFU
34 RFU
36 RFU
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Pin Layout
TOP VIEW
NOTE:
The pins defined as NC/RFU shall be considered RESERVED and must not be
connected to any pin in the application.
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4. POWER SUPPLY
The power supply circuitry and board layout are a very important part in
the full product design and they strongly reflect on the product overall
performance, hence read the requirements carefully and the guidelines
that will follow for a proper design.
Power Supply Requirements
The external power supply must be connected to VBATT & VBATT_PA
signals and must fulfill the following requirements:
Power Supply
Nominal Supply Voltage 3.8V
Operating Voltage Range 3.40 V÷ 4.20 V
Extended Voltange Range
NOTE:
The Operating Voltage Range MUST never be exceeded; care must
be taken when designing the application’s power supply section to
avoid having an excessive voltage drop. If the voltage drop is
exceeding the limits it could cause a Power Off of the module.
The Power supply must be higher than 3.20 V to power on the
Value
3.20 V÷ 4.50 V
module.
Overshoot voltage (regarding MAX Extended Operating Voltage) and
drop in voltage (regarding MIN Extended Operating Voltage) MUST
never be exceeded;
The “Extended Operating Voltage Range” can be used only with
completely assumption and application of the HW User guide
suggestions.
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GSM 850/900
NOTE:
For PTCRB approval on the final products the power supply is
required to be within the “Normal Operating Voltage Range”.
Power Consumption
*Preliminary data
Mode
Average
(mA)
Mode Description
Switched off 0.008mA Module supplied but switched off
IDLE mode
AT+CFUN=1 12 mA Normal mode: full functionality of the module
AT+CFUN=4 11 mA Disabled TX and RX; module is not registered on the
network
AT+CFUN=5 2.3 mA Paging cycle #64 frames (0.64 sec DRx cycle)
1.4 mA Paging cycle #128 frames (1.28 sec DRx cycle)
1.1 mA Paging cycle #256 frames (2.56 sec DRx cycle)
Operative Mode
LTE Data call 190 mA CAT M1 RB=1, TX=23dBm
115 mA CAT M1 Channel BW 10MHz, RB=1, TX=0dBm
GPRS
1TX+1RX
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240 mA
GPRS Sending data mode, TX=33dBm
ML865C1 HW User Guide
GPRS
170 mA
GPRS Sending data mode, TX=30dBm
1TX+1RX
GSM 1800/1900
PSM Mode
AT+CPSMS=1 0.008mA No current source or sink by any connected pin
GNSS ACTIVE
GNSS 29 mA GNSS Standalone 1Hz Acquisition ( Non-Dpo)
GNSS 30 mA GNSS Standalone 1Hz Tracking ( Non-DPO)
GPS 28 mA GPS Standalone 1Hz Acquisition ( Non-Dpo)
GPS 29 mA GPS Standalone 1Hz Tracking ( Non-DPO)
4.2.1. Current consumption plots
1800
1600
1400
Current (mA)
1200
1000
800
600
400
Current Profile at Max Power (23 dBm)
Average Value at Max Power
Current Profile at Low Power (<0 dBm)
Average Value at Low Power
200
Time (ms)
0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Current Consumption in LTE data call CAT M1
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Current Consumption in GPRS 1 slot TX
1800
1600
1400
1200
Current (mA)
1000
800
600
400
Current Profile at Max Power (33 dBm)
Average Value at Max Power
Current Profile at Low Power (< 0 dBm)
Average Value at Low Power
200
0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (ms)
NOTE: The electrical design for the Power supply should be made
ensuring it will be capable of a peak current output of at least:
0.6 A for LTE mode (3.80V supply).
2A for GPRS mode (3.80V supply).
NOTE: The reported LTE values are an average among all the
product variants and bands for each network wireless technology.
The support of specific network wireless technology depends on
product variant configuration.
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General Design Rules
The principal guidelines for the Power Supply Design embrace three different design
steps:
the electrical design of the power supply
the thermal design
the PCB layout
4.3.1. Electrical Design Guidelines
The electrical design of the power supply depends strongly from the
power source where this power is drained. We will distinguish them into
three categories:
+5V input (typically PC internal regulator output)
+12V input (typically automotive)
Battery
4.3.1.1. +5V Source Power Supply Design Guidelines
The desired output for the power supply is 3.8V, hence there's not a
big difference between the input source and the desired output and
a linear regulator can be used. A switching power supply will not be
suited because of the low drop out requirements.
When using a linear regulator, a proper heat sink shall be provided
in order to dissipate the power generated.
A Bypass low ESR capacitor of adequate capacity must be provided
in order to cut the current absorption peaks close to the ML865C1, a
100μF tantalum capacitor is usually suited.
Make sure the low ESR capacitor on the power supply output (usually
a tantalum one) is rated at least 10V.
A protection diode should be inserted close to the power input, in
order to save the ML865C1 from power polarity inversion.
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An example of linear regulator with 5V input is:
Guidelines
4.3.1.2. +12V Source Power Supply Design Guidelines
The desired output for the power supply is 3.8V, hence due to the big
difference between the input source and the desired output, a linear
regulator is not suited and shall not be used. A switching power
supply will be preferable because of its better efficiency especially
with the 2A peak current load represented by the ML865C1.
When using a switching regulator, a 500kHz or more switching
frequency regulator is preferable because of its smaller inductor size
and its faster transient response. This allows the regulator to respond
quickly to the current peaks absorption.
In any case the frequency and Switching design selection is related
to the application to be developed due to the fact the switching
frequency could also generate EMC interferences.
For car PB battery the input voltage can rise up to 15,8V and this
should be kept in mind when choosing components: all components
in the power supply must withstand this voltage.
A Bypass low ESR capacitor of adequate capacity must be provided
in order to cut the current absorption peaks, a 100μF tantalum
capacitor is usually suited.
Make sure the low ESR capacitor on the power supply output (usually
a tantalum one) is rated at least 10V.
For Car applications a spike protection diode should be inserted
close to the power input, in order to clean the supply from spikes.
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A protection diode should be inserted close to the power input, in
order to save the ML865C1 from power polarity inversion. This can
be the same diode as for spike protection.
An example of switching regulator with 12V input is in the below
schematic:
4.3.1.3. Battery Source Power Supply Design Guidelines
A single 3.7V Li-Ion cell battery type is suited for supply of Telit ML865C1
module.
WARNING:
The three cells Ni/Cd or Ni/MH 3,6 V Nom. battery types or 4V PB types
MUST NOT BE USED DIRECTLY since their maximum voltage can rise
over the absolute maximum voltage for the ML865C1 and damage it.
NOTE:
DON'T USE any Ni-Cd, Ni-MH, and Pb battery types directly connected with
ML865C1. Their use can lead to overvoltage on the ML865C1 and damage it.
USE ONLY Li-Ion battery types.
A Bypass low ESR capacitor of adequate capacity must be provided in
order to cut the current absorption peaks, a 100μF tantalum capacitor is
usually suited.
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Make sure the low ESR capacitor (usually a tantalum one) is rated at
least 10V.
A protection diode should be inserted close to the power input, in order
to save the ML865C1 from power polarity inversion. Otherwise the
battery connector should be done in a way to avoid polarity inversions
when connecting the battery.
The battery capacity must be at least 500mAh in order to withstand the
current peaks of 2A; the suggested capacity is from 500mAh to
1000mAh.
1VV0301493 Rev. 4 Page 27 of 89 2020-07-27
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