Telit Wireless Solutions GL865 V3, GL865 V3.1 User Manual

[0

1.2017]

Mod. 08

05 2017-01 Rev.6

GL865 V3/V3.1

HW User Guide

1vv0301018 Rev. 15 – 2019-01-07

HW User Guide

1vv0301018 Rev. 15 Page 2 of 72 2019-01-07

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.

HW User Guide

1vv0301018 Rev. 15 Page 3 of 72 2019-01-07

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.

HW User Guide

1vv0301018 Rev. 15 Page 4 of 72 2019-01-07

APPLICABILITY TABLE

PRODUCTS

GL865-DUAL V3

GL865-QUAD V3

GL865-DUAL V3.1

GL865-QUAD V3.1

HW User Guide

1vv0301018 Rev. 15 Page 5 of 72 2019-01-07

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 .......................................................................... 8

Scope ........................................................................................... 8

Audience....................................................................................... 8

Contact Information, Support ........................................................ 8

Text Conventions .......................................................................... 9

Related Documents .................................................................... 10

2. OVERVIEW ................................................................................ 11

3. GL865 V3/V3.1 MECHANICAL DIMENSIONS ........................... 12

4. GL865 V3/V3.1 MODULE CONNECTIONS ................................ 13

PIN-OUT ..................................................................................... 13

Pin Layout ................................................................................... 15

5. HARDWARE COMMANDS ........................................................ 16

Auto-Turning ON the GL865 V3/V3.1 .......................................... 16

Turning OFF the GL865 V3/V3.1 ................................................ 17

Fast SYSHALT the GL865 V3/V3.1 ............................................ 19

5.3.1. Fast SYSHALT by Hardware ...................................................... 19

Resetting the GL865 V3/V3.1 ..................................................... 21

5.4.1. Hardware Unconditional restart ................................................... 21

6. POWER SUPPLY ....................................................................... 23

Power Supply Requirements ....................................................... 23

Power Consumption ................................................................... 24

HW User Guide

1vv0301018 Rev. 15 Page 6 of 72 2019-01-07

General Design Rules ................................................................. 25

6.3.1. Electrical Design Guidelines ....................................................... 25

6.3.1.1. + 5V input Source Power Supply Design Guidelines ................... 25

6.3.1.2. + 12V input Source Power Supply Design Guidelines ................. 26

6.3.1.3. Battery Source Power Supply Design Guidelines .............................. 27

6.3.2. Thermal Design Guidelines ......................................................... 28

6.3.3. Power Supply PCB layout Guidelines ......................................... 29

7. ANTENNA .................................................................................. 30

GSM Antenna Requirements ...................................................... 30

7.1.1. GL865 V3/V3.1 Antenna – PCB line Guidelines .......................... 30

PCB Design Guidelines .............................................................. 32

7.2.1. Transmission line design ............................................................ 32

7.2.2. Transmission line measurements ............................................... 33

GSM Antenna - Installation Guidelines ....................................... 35

8. LOGIC LEVEL SPECIFICATIONS ............................................. 36

Reset signal ................................................................................ 37

9. SERIAL PORTS ......................................................................... 38

MODEM SERIAL PORT ............................................................. 38

RS232 level translation ............................................................... 40

10. AUDIO SECTION OVERVIEW ................................................... 42

MIC connection ........................................................................... 42

LINE-IN connection ..................................................................... 43

EAR connection .......................................................................... 44

Electrical Characteristics ............................................................. 46

10.4.1. Input Lines .................................................................................. 46

10.4.2. Output Lines ............................................................................... 46

11. GENERAL PURPOSE I/O .......................................................... 47

GPIO Logic levels ....................................................................... 48

Using a GPIO Pad as INPUT ...................................................... 49

Using a GPIO Pad as OUTPUT .................................................. 49

Using the RF Transmission Control GPIO4 ................................. 49

Using the RFTXMON Output GPIO5 ........................................... 49

Using the Alarm Output GPIO6 ................................................... 50

Using the Buzzer Output GPIO7 ................................................. 50

Magnetic Buzzer Concepts ......................................................... 51

11.8.1. Short Description ........................................................................ 51

HW User Guide

1vv0301018 Rev. 15 Page 7 of 72 2019-01-07

11.8.2. Frequency Behavior .................................................................... 51

11.8.3. Power Supply Influence ................................................................ 51

11.8.4. Working Current Influence .......................................................... 52

STAT LED Indication of network service availability .................... 52

SIMIN detect function.................................................................. 53

RTC Bypass out .......................................................................... 53

SIM Holder Implementation ........................................................ 53

12. DAC AND ADC SECTION .......................................................... 54

DAC Converter ........................................................................... 54

12.1.1. Description .................................................................................. 54

12.1.2. Enabling DAC ............................................................................. 55

12.1.3. Low Pass Filter Example ............................................................ 55

ADC Converter ........................................................................... 56

12.2.1. Description .................................................................................. 56

12.2.2. Using ADC Converter ................................................................. 56

13. MOUNTING THE GL865 V3/V3.1 ON YOUR BOARD ............... 57

General ....................................................................................... 57

Module finishing & dimensions .................................................... 57

Recommended foot print for the application ................................ 58

Stencil ......................................................................................... 59

PCB pad design .......................................................................... 59

Recommendations for PCB pad dimensions (mm): ..................... 59

Solder paste ............................................................................... 60

GL865 V3/V3.1 Solder reflow ...................................................... 61

Debug of the GL865 V3/V3.1 in production ................................. 62

14. PACKING SYSTEM ................................................................... 63

Packing on tray ........................................................................... 63

Packing on reel ........................................................................... 65

14.2.1. Carrier tape detail ....................................................................... 66

14.2.2. Carrier detail ............................................................................... 66

Moisture sensibility ..................................................................... 67

15. CONFORMITY ASSESSMENT ISSUES .................................... 68

16. SAFETY RECOMMENDATIONS................................................ 70

17. DOCUMENT HISTORY .............................................................. 71

HW User Guide

1vv0301018 Rev. 15 Page 8 of 72 2019-01-07

1. INTRODUCTION

Scope

The aim of this document is the description of some hardware solutions useful for
developing a product with the Telit GL865 V3/V3.1 module.

Audience

This document is intended for Telit customers, who are integrators, about to implement their
applications using our GL865 V3/V3.1 modules.

Contact Information, Support

For general contact, technical support services, technical questions and report
documentation errors contact Telit Technical Support at:

• [e-mail]

• [e-mail]

• [e-mail]

• [e-mail]

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.

HW User Guide

1vv0301018 Rev. 15 Page 9 of 72 2019-01-07

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.

HW User Guide

1vv0301018 Rev. 15 Page 10 of 72 2019-01-07

Related Documents

• Telit's GSM/GPRS Family Software User Guide, 1vv0300784

• Audio settings application note , 80000NT10007a

• GL865/GL868 V3 Digital Voice Interface Application Note, 80000NT10104a

• GL865 V3/V3.1 Product description, 80400ST10120a

• SIM Integration Design Guide Application Note, 80000NT10001a

• AT Commands Reference Guide, 80000ST10025a

• Telit EVK2 User Guide, 1vv0300704

• Telit modem integration design guide, 1VV0301189

HW User Guide

1vv0301018 Rev. 15 Page 11 of 72 2019-01-07

GL865 V3/V3.1

2. OVERVIEW

The aim of this document is the description of some hardware solutions useful for
developing a product with the Telit GL865 V3/V3.1 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 all hardware solutions and products that may be designed. Avoiding the
wrong solutions shall be considered as mandatory. While the suggested hardware
configurations shall not be considered mandatory, the information given shall be used as a
guide and a starting point for properly developing your product with the Telit GL865 V3/V3.1
module. For further hardware details that may not be explained in this document refer to the
Telit GL865 V3/V3.1 Product Description document where all the hardware information is
reported.

NOTE:

(EN) The integration of the GSM/GPRS GL865 V3/V3.1 cellular
module within user application shall be done according to the design
rules described in this manual.

(IT) L’integrazione del modulo cellulare GSM/GPRS GL865 V3/V3.1
all’interno dell’applicazione dell’utente dovrà rispettare le indicazioni
progettuali descritte in questo manuale.

(DE) Die Integration des GSM/GPRS GL865 V3/V3.1 Mobilfunk­Moduls in ein Gerät muß gemäß der in diesem Dokument
beschriebenen Kunstruktionsregeln erfolgen.

(SL) Integracija GSM/GPRS GL865 V3/V3.1 modula v uporabniški
aplikaciji bo morala upoštevati projektna navodila, opisana v tem
priročniku.

(SP) La utilización del modulo GSM/GPRS GL865 V3/V3.1 debe ser
conforme a los usos para los cuales ha sido deseñado descritos en
este manual del usuario.

(FR) L’intégration du module cellulaire GSM/GPRS GL865 V3/V3.1
dans l’application de l’utilisateur sera faite selon les règles de
conception décrites dans ce manuel.

(HE)

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.

HW User Guide

1vv0301018 Rev. 15 Page 12 of 72 2019-01-07

3. GL865 V3/V3.1 MECHANICAL DIMENSIONS

The GL865 V3/V3.1 overall dimensions are:

• Length: 24.4 mm

• Width: 24.4 mm

• Thickness: 2.6 mm

• Weight 2.8 g

HW User Guide

1vv0301018 Rev. 15 Page 13 of 72 2019-01-07

4. GL865 V3/V3.1 MODULE CONNECTIONS

PIN-OUT

Pad Signal I/O Function Note Type

Audio

20 EAR- AO Earphone signal output, phase - Audio

21

EAR+ AO Earphone signal output, phase + Audio

22

MIC-

AI

Mic. signal input; phase-

Audio

24 MIC+ AI Mic. signal input; phase+ Audio

23 AGND - Analog Ground -

SIM card interface

9

SIMVCC

-

External SIM signal – Power supply for the SIM

1,8 / 3V

10 SIMRST O External SIM signal – Reset 1,8 / 3V

11 SIMCLK O External SIM signal – Clock 1,8 / 3V

12

SIMIO I/O External SIM signal – Data I/O 4.7KΩ PU 1,8 / 3V

X

All GPI0

can be

program

med

SIMIN I Presence SIM input CMOS 1.8V

Trace

44 RXD_AUX I Auxiliary UART (RX Data) 12KΩ PU CMOS 1.8V

45

TXD_AUX O Auxiliary UART (TX Data) CMOS 1.8V

Prog. / Data + HW Flow Control

1 C109/DCD/GPO O

Output for Data carrier detect signal (DCD) to DTE

/ GP output

CMOS 1.8V

2 C125/RING/GPO O

Output for Ring indicator signal (RI) to DTE

/ GP output

CMOS 1.8V

3 C107/DSR/GPO O

Output for Data set ready signal (DSR) to DTE

/ GP output

CMOS 1.8V

4 C108/DTR/GPI I

Input for Data terminal ready signal (DTR) from DTE

/ GP input

30KΩ PU CMOS 1.8V

5 C105/RTS/GPI I

Input for Request to send signal (RTS) from DTE

/ GP input

30KΩ PU CMOS 1.8V

6 C106/CTS/GPO O

Output for Clear to send signal (CTS) to DTE

/ GP output

CMOS 1.8V

7

C103/TXD I Serial data input (TXD) from DTE 12KΩ PU CMOS 1.8V

8

C104/RXD O Serial data output to DTE CMOS 1.8V

DAC and ADC

13 ADC_IN1 AI Analog/Digital converter input A/D

14

ADC_IN2 AI Analog/Digital converter input A/D

15

DAC_OUT AO Digital/Analog converter output D/A

Miscellaneous Functions

30 VRTC AO VRTC Backup 2.3V Power

47 RESET* I Reset input 2KΩ PU CMOS 1.8V

43 V_AUX / PWRMON O

1.8V stabilized output Imax=100mA
/ Power ON monitor

Power Out 1.8V

34

Antenna I/O Antenna pad – 50 Ω RF

GPIO

42 GPIO_01 / DVI_WA0 I/O

GPIO01 Configurable GPIO

/ Digital Audio Interface (WA0)

80KΩ-

110KΩ PD

CMOS 1.8V

41

GPIO_02 / JDR /

DVI_RX

I/O

GPIO02 I/O pin

/ Jammer Detect Report

/ Digital Audio Interface (RX)

18KΩ-

25KΩ PD

CMOS 1.8V

40 GPIO_03 / DVI_TX I/O

GPIO03 GPIO I/O pin

/ Digital Audio Interface (TX)

80KΩ-

110KΩ PD

CMOS 1.8V

39

GPIO_04 / TX

Disable / DVI_CLK

I/O

GPIO04 Configurable GPIO

/ TX Disable input

/ Digital Audio Interface (CLK)

18KΩ-

25KΩ PD

CMOS 1.8V

HW User Guide

1vv0301018 Rev. 15 Page 14 of 72 2019-01-07

Pad Signal I/O Function Note Type

29

GPIO_05 /
RFTXMON

I/O

GPIO05 Configurable GPIO

/ Transmitter ON monitor

28KΩ-

40KΩ PD

CMOS 1.8V

28 GPIO_06 / ALARM I/O

GPIO06 Configurable GPIO

/ ALARM

28KΩ-

40KΩ PD

CMOS 1.8V

27 GPIO_07 / BUZZER I/O

GPIO07 Configurable GPIO

/ Buzzer

28KΩ-

40KΩ PD

CMOS 1.8V

26

GPIO_08 /

STAT_LED

I/O

GPIO08 Configurable GPIO

/Status LED

28KΩ-

40KΩ PD

CMOS 1.8V

Power Supply

38 VBATT - Main power supply (Baseband) Power

37

VBATT_PA - Main power supply (Radio PA) Power

23 AGND - AF Signal Ground (see audio section) AF Signal

32 GND - Ground Power

33 GND - Ground Power

35 GND - Ground Power

36

GND - Ground Power

46

GND - Ground Power

RESERVED

48 -

16 -

17 -

18

-

19 -

25 -

31

-

WARNING

Reserved pins must not be connected.

NOTE:

If not used, almost all pins should be left disconnected. The only exceptions

are the following pins:

Pin

signal

38, 37

VBATT & VBATT_PA

32, 33, 35, 36, 46

GND

23

AGND

7

TXD

8

RXD

5

RTS

43

V_AUX / PWRMON

47

RESET*

45

TXD_AUX

44

RXD_AUX

HW User Guide

1vv0301018 Rev. 15 Page 15 of 72 2019-01-07

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.

HW User Guide

1vv0301018 Rev. 15 Page 16 of 72 2019-01-07

5. HARDWARE COMMANDS

Auto-Turning ON the GL865 V3/V3.1

To Auto-turn on the GL865 V3/V3.1, the power supply must be applied on the power pins
VBATT and VBATT_PA, after 1000 m-seconds, the V_AUX / PWRMON pin will be at the
high logic level and the module can be considered fully operating.

When the power supply voltage is between 3.22V and 3.4V, after 5000 m-seconds, the
V_AUX / PWRMON pin will be at the high logic level and the module can be considered
fully operating.

The following flow chart shows the proper turn on procedure:

NOTE:

The power supply must be applied either at the same time on pins VBATT
and VBATT_PA, or first applied on VBATT_PA and then on VBATT. The

opposite sequence shall be avoided. The reverse procedure applies for

powering down the module: first disconnect VBATT, then VBATT_PA, or

both at once.

Modem ON Proc.

PWR supply = ON?

Y

Delay 1s - 5s for Low

Voltage Operating

Y

Modem Reset Proc.

AT init sequence.

N

Start AT CMD.

N

PWMON = ON?

Y

PWMON = ON?

Delay 300mS

Enter AT<CR>

AT answer in 1 second

?

N

Y

N

Delay 1s

HW User Guide

1vv0301018 Rev. 15 Page 17 of 72 2019-01-07

NOTE:

In order to prevent a back powering effect it is recommended to avoid
having any HIGH logic level signal applied to the digital pins of the GL865

V3/V3.1 when the module is powered OFF or during an ON/OFF transition.

A flow chart showing the AT commands managing procedure is displayed below:

Turning OFF the GL865 V3/V3.1

Turning off of the device can be done in two ways:

• General turn OFF

• Processor turn OFF

General turn OFF – disconnect the power supply from the both power pins VBATT and
VBATT_PA at the same time. In this case all parts of the module are in OFF condition, no
power consumption is present.

Processor turn OFF – disconnect the power supply only from the power pin VBATT, the
power pin VBATT_PA can be connected to power supply, in this case a low, about 30uA,
power consumption is present

Before either of both OFF procedures is applied, the AT#SYSHALT AT command must be
sent (see AT Commands Reference Guide, 80000ST10025a), after the OK response
message, wait for 10 seconds, then the module can be consider fully not operating and at
this moment is possible disconnect the Power Supply.

Modem ON Proc.

Disconnect PWR supply

AT init sequence.

Delay 300mS

Enter AT<CR>

AT answer in 1

second?

Y

N

Start AT CMD.

HW User Guide

1vv0301018 Rev. 15 Page 18 of 72 2019-01-07

The following flow chart shows the proper turnoff procedure:

WARNING:

POWERMON can be used to monitor only the power on but it cannot be
used to monitor the power off because it remains high. Instead

AT#SYSHALT works in the same way as previous GL865-DUAL/QUAD.

NOTE:

In order to prevent a back powering effect it is recommended to avoid having
any HIGH logic level signal applied to the digital pins of the GL865 V3/V3.1

when the module is powered off or during an ON/OFF transition.

Modem OFF Proc.

AT#SYSHALT

Disconnect PWR supply

10s timeout

Modem ON Proc.

Delay 1.5s

HW User Guide

1vv0301018 Rev. 15 Page 19 of 72 2019-01-07

Fast SYSHALT the GL865 V3/V3.1

The procedure to power OFF of module described in Chapter 5.2, normally takes up to 10
second to de-attach the network and internal filesystem properly closed.

The Fast SYSHALT feature permits to reduce the current consumption and the time-to­power SYSHALT to minimum values.

NOTE:

Refer to AT command reference guide (Fast Sys Halt - #FASTSYSHALT) in
order to set up detailed AT command.

5.3.1. Fast SYSHALT by Hardware

The module provides an input to give to the FW of the module advance notice that the power
source is failing and allow it to prepare for the power failure.

The Fast SYSHALT can be triggered by configuration of any GPIO. HIGH level to LOW
level transition of GPIO forces the fast power down procedure.

NOTE:

Consider voltage drop under max current conditions when defining the

voltage detector threshold in order to avoid unwanted shutdown.

HW User Guide

1vv0301018 Rev. 15 Page 20 of 72 2019-01-07

Typical timings are reported in the plot above when testing the example circuit with
Ctank=47mF. The capacitor is rated with the following formula:

Where 80mA is a typical current during fast SYSHALT procedure, 300ms is the typical time
to execute the system halt and 0.5V is the minimum voltage margin from threshold of
hardware reset.

NOTE:

Verify carefully the timings and failure voltages levels during system
verifications.

WARNING:

Ctank associated with low ESR requires current limiting feature in DCDC
converter to avoid side effect of inrush current.

HW User Guide

1vv0301018 Rev. 15 Page 21 of 72 2019-01-07

Resetting the GL865 V3/V3.1

5.4.1. Hardware Unconditional restart

WARNING:

The hardware unconditional Restart must not be used

during normal

operation of the device since it does not detach the device from the network.
It shall be kept as an emergency exit procedure to be done in the rare case
that the device gets stuck waiting for some network or SIM responses.

To unconditionally reboot the GL865 V3/V3.1, the pad RESET* must be tied low for at least
200 milliseconds and then released.

The maximum current that can be drained from the ON* pad is 0,15 mA.

NOTE:

Do not use any pull up resistor on the RESET* line nor any totem pole digital
output. Using pull up resistor may bring to latch up problems on the GL865
V3/V3.1 power regulator and improper functioning of the module. The line

RESET* must be connected only in open collector configuration; the
transistor must be connected as close as possible to the RESET* pin.

TIP:

The unconditional hardware restart must always be implemented on the

boards and the software must use it as an emergency exit procedure.

A simple circuit to do it is:

HW User Guide

1vv0301018 Rev. 15 Page 22 of 72 2019-01-07

In the following flow chart is detailed the proper restart procedure:

NOTE:

In order to prevent a back powering effect it is recommended to avoid having
any HIGH logic level signal applied to the digital pins of the GL865 V3/V3.1

when the module is powered OFF or during an ON/OFF transition.

Modem Reset

Proc.

Reset = LOW

Delay 200ms

Reset = HIGH

Delay 1s

Start AT CMD.