Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 4 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
DISCLAIMER
The information contained in this document is the proprietary information of Telit Communications
S.p.A. and its affiliates (“TELIT”). The contents are confidential and any disclosure to persons other
than the officers, employees, agents or subcontractors of the owner or licensee of this document,
without the prior written consent of Telit, is strictly prohibited.
Telit makes every effort to ensure the quality of the information it makes available. Notwithstanding the
foregoing, Telit does not make any warranty as to the information contained herein, and does not
accept any liability for any injury, loss or damage of any kind incurred by use of or reliance upon the
information.
Telit disclaims any and all responsibility for the application of the devices characterized in this
document, and notes that the application of the device must comply with the safety standards of the
applicable country, and where applicable, with the relevant wiring rules.
Telit reserves the right to make modifications, additions and deletions to this document due to
typographical errors, inaccurate information, or improvements to programs and/or equipment at any
time and without notice. Such changes will, nevertheless be incorporated into new editions of this
application note.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 5 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
1 Overview
The aim of this document is the description of some hardware solutions useful for developing a product with the
Telit UC864-E 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 UC864-E module. For further
hardware details that may not be explained in this document refer to the Telit UC864-E Product Description
document where all the hardware information is reported.
NOTICE
(EN) The integration of the GSM/GPRS/EGPRS/WCDMA/HSDPA UC864-E
application shall be done according to the design rules described in this manual.
(IT) L’integrazione del modulo cellulare GSM/GPRS/EGPRS/WCDMA/HSDPA UC864-E all’interno
dell’applicazione dell’utente dovrà rispettare le indicazioni progettuali descritte in questo manuale.
(DE) Die integration des UC864-E GSM/GPRS/EGPRS/WCDMA/HSDPA Mobilfunk-Moduls in ein Gerät
muß gemäß der in diesem Dokument beschriebenen Kunstruktionsregeln erfolgen
(SL) Integracija GSM/GPRS/EGPRS/WCDMA/HSDPA UC864-E modula v uporabniški aplikaciji bo morala
upoštevati projektna navodila, opisana v tem piročniku.
(SP) La utilización del modulo GSM/GPRS/EGPRS/WCDMA/HSDPA UC864-E 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/EGPRS/WCDMA/HSDPA UC864-E dans l’application
de l’utilisateur sera faite selon les règles de conception décrites dans ce manuel.
cellular module within user
UC864-E
The information presented in this document is believed to be accurate and reliable. However, no respo nsibility 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.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 6 of 51
2 Mechanical Dimensions
The Telit UC864-E module overall dimensions are:
• Length: 36.2 mm
• Width: 30 mm
• Thickness: 4.8mm
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 7 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
3 UC864-E module connections
3.1 PIN-OUT
UC864-E uses an 80-pin Molex p.n. 53949-0878 male connector for the connections with the external
applications. This connector matches the 54150-0878 models
Pin Signal I/O Function
Power Supply
1 VBATT - Main power supply Power
2 VBATT - Main power supply Power
3 VBATT - Main power supply Power
4 VBATT - Main power supply Power
5 GND - Ground Power
6 GND - Ground Power
7 GND - Ground Power
Audio
8 AXE I Hands-free switching
9 EAR_HF+ AO Hands-free ear output, phase + Audio
10 EAR_HF- AO Hands-free ear output, phase - Audio
11 EAR_MT+ AO Handset earphone signal output, phase + Audio
12 EAR_MT- AO Handset earphone signal output, phase - Audio
13 MIC_HF+ AI Hands-free microphone input; phase + Audio
14 MIC_HF- AI Hands-free microphone input; phase - Audio
15 MIC_MT+ AI Handset microphone signal input; phase+ Audio
16 MIC_MT- AI Handset microphone signal input; phase- Audio
SIM Card Interface
181 SIMVCC - External SIM signal – Power supply for the SIM 1.8 / 3V
19 SIMRST O External SIM signal – Reset 1.8 / 3V
20 SIMIO I/O External SIM signal - Data I/O 1.8 / 3V
21 SIMIN I External SIM signal - Presence (active low)
22 SIMCLK O External SIM signal – Clock 1.8 / 3V
Trace
.
Internal
Pull up
100KΩ
47KΩ
Type
UC864-E
CMOS 2.6V
1.8 / 3V
1
On this line a maximum of 10nF bypass capacitor is allowed
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 8 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
Pin Signal I/O Function
23 RX_TRACE I RX Data for debug monitor CMOS 2.6V
24 TX_TRACE O TX Data for debug monitor CMOS 2.6V
Prog. / Data + Hw Flow Control
25 C103/TXD I Serial data input (TXD) from DTE CMOS 2.6V
26 C104/RXD O Serial data output to DTE CMOS 2.6V
27 C107/DSR O Output for Data set ready signal (DSR) to DTE CMOS 2.6V
28 C106/CTS O Output for Clear to send signal (CTS) to DTE CMOS 2.6V
29 C108/DTR I Input for Data terminal ready signal (DTR) from DTE CMOS 2.6V
30 C125/RING O Output for Ring indicator signal (RI) to DTE CMOS 2.6V
31 C105/RTS I Input for Request to send signal (RTS) from DTE CMOS 2.6V
32 C109/DCD O Output for Data carrier detect signal (DCD) to DTE CMOS 2.6V
Miscellaneous Functions
35 USB_ID AI
36 PCM_CLOCK I/O PCM clock out CMOS 2.6V
37 ADC_IN1 AI Analog/Digital converter input A/D
38 ADC_IN2 AI Analog/Digital converter input A/D
39 ADC_IN3 AI Analog/Digital converter input A/D
40 DAC_OUT AO Digital/Analog converter output D/A(PDM)
45 STAT_LED O Status indicator led CMOS 1.8V
46 GND - Ground Ground
48 USB_VBUS
49 PWRMON O Power ON Monitor CMOS 2.6V
50 VAUX1 - Power output for external accessories 2.85V
51 CHARGE AI Charger input Power
52 CHARGE AI Charger input Power
RTS should be connected to the GND (on the module side) if flow control is not used
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 10 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
NOTE: If not used, almost all pins should be left disconnected. The only exceptions are the following
pins:
Pin Signal Function
1 VBATT Main power supply
2 VBATT Main power supply
3 VBATT Main power supply
4 VBATT Main power supply
5 GND Ground
6 GND Ground
7 GND Ground
46 GND Ground
25 C103/TXD Serial data input (TXD) from DTE
26 C104/RXD Serial data output to DTE
31 C105/RTS Input for Request to send signal (RTS) from DTE
53 ON/OFF* Input command for switching power ON or OFF (toggle command).
54 RESET# Reset input
35 USB_ID
48 USB_VBUS
79 USB_D+ USB differential Data (+)
80 USB_D- USB differential Data (-)
Analog input used to sense whether a peripheral device is
connected, and determine the peripheral type, a host or a peripheral
Power supply for the internal USB transceiver. This pin is configured
as an analog input or an analog output depending upon the type of
peripheral device connected.
3.1.1 UC864-E Antenna connector
The UC864-E module is equipped with a RF connector from Murata, GSC type P/N MM9329-2700B.
The counterpart suitable is Murata MXTK92 Type or MXTK88 Type.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 11 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
4 Hardware Commands
4.1 Turning ON the UC864-E
To turn on UC864-E, the pad ON# must be tied low for at least 1 second and then released.
The maximum current that can be drained from the ON# pad is 0,1 mA.
A simple circuit to do it is:
ON#
R1
Q1
Power ON impulse
R2
GND
NOTE: UC864-E turns fully on also by supplying power to the USB_VBUS pin (provided there's a battery on the
VBATT pads). Care must be taken to avoid supplying power to the USB_VBUS pin before the module turns on.
To check if the UC864-E has powered on, the hardware line PWRMON should be monitored. When PWRMON goes
high, the module has powered on.
NOTE: don't use any pull up resistor on the ON# line, it is internally pulled up. Using pull up resistor may bring to
latch up problems on the UC864-E power regulator and improper power on/off of the module. The line ON# must be
connected only in open collector configuration.
NOTE: In this document all the lines that are inverted, hence have active low signals are labeled with a name that
ends with a "#" or with a bar over the name.
NOTE: UC864-E turns fully on also by supplying power to the Charge pad (provided there's a battery on the VBATT
pads).
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 12 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
For example:
1- Let's assume you need to drive the ON# pad with a totem pole output of a 1.8/5 V microcontroller
(uP_OUT1):
2- Let's assume you need to drive the ON# pad directly with an ON/OFF button:
10k
1.8 / 5V
1s
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 13 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
4.2 Turning OFF the UC864-E
The turning off of the device can be done in three ways:
• By software command (see UC864-E Software User Guide)
• By hardware shutdown
• By Hardware Unconditional Restart
When the device is shut down by software command or by hardware shutdown, it issues to the
network a detach request that informs the network that the device will not be reachable any more.
4.2.1 Hardware shutdown
To turn OFF UC864-E, first, you MUST cut off supplying power to the USB_VBUS pin, then the pad
ON# must be tied low for at least 2 seconds and then released.
The same circuitry and timing for the power on shall be used.
The device shuts down after the release of the ON# pad.
NOTE: To turn OFF UC864-E, first of all, you MUST cut off supplying power to the USB_VBUS, or the module does
not turn off
TIP: To check if the device has powered off, the hardware line PWRMON should be monitored. When PWRMON goes
low, the device has powered off.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 14 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
4.2.2 Hardware Unconditional Restart
To unconditionally restart UC864-E, 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.
A simple circuit to do it is:
NOTE: Do not use any pull up resistor on the RESET# line or any totem pole digital output. Using pull up resistor
may bring to latch up problems on the UC864-E power regulator and improper functioning of the module. The line
RESET# must be connected only in open collector configuration.
TIP: The unconditional hardware Restart should be always implemented on the boards and software should use it
as an emergency exit procedure.
Unconditional Restart
impulse
RESET#
GND
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 15 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
For example:
1- Let's assume you need to drive the RESET# pad with a totem pole output of a +1.8/5 V micro
controller (uP_OUT2):
10k
+1.8 / 5V
* This signal is internally pulled up so the pin can be left floating if not used.
NOTE: If UC864-E is connected as USB slave (considering also the presence of VBATT supply), when
powered off it automatically switch on again.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 16 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
5 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 performances, hence read carefully the requirements and
the guidelines that will follow for a proper design.
5.1 Power Supply Requirements
POWER SUPPLY
Nominal Supply Voltage 3.8V
Max Supply Voltage 4.2
Supply Voltage Range 3.51 – 4.2
The UC864-E power consumptions are:
UC864-E (GSM900)
Mode Average (mA) Mode description
IDLE mode
AT+CFUN=1 21,7
AT+CFUN=4 21,3
AT+CFUN=0 or
AT+CFUN=5
GSM TX and RX mode
Min power level 139.1
Max power level 340.8
GPRS (class 10) TX and RX mode
Max power level 728.2
WCDMA
Max power level 619,7
In GSM/GPRS mode, RF transmission is not continuous and it is packed into bursts at a base
frequency of about 216 Hz, and the relative current peaks can be as high as about 2A. Therefore the
power supply has to be designed in order to withstand with these current peaks without big voltage
drops; this means that both the electrical design and the board layout must be designed for this
current flow.
3,3
Normal mode: full functionality of the module (MF=9)
Disabled TX and RX; module is not registered on the
Power saving: CFUN=0 module registered on the network
and can receive voice call or an SMS; but it is not possible
to send AT commands; module wakes up with an
unsolicited code (call or SMS) or rising RTS line. CFUN=5
full functionality with power saving; module registered on
the network can receive incoming calls and SMS – (MF=2)
Stand by mode; no call in progress
network
GSM Sending data mode
GPRS Sending data mode (3 slot TX)
WCDMA Call in progress
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 17 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
If the layout of the PCB is not well designed a strong noise floor is generated on the ground and the
supply; this will reflect on all the audio paths producing an audible annoying noise at 216 Hz; if the
voltage drop during the peak current absorption is too much, then the device may even shutdown as a
consequence of the supply voltage drop.
TIP: The electrical design for the Power supply should be made ensuring it will be capable of a peak current output
of at least 2 A.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 18 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
5.2 General Design Rules
The principal guidelines for the Power Supply Design embrace three different design steps:
• The electrical design
• The thermal design
• The PCB layout.
5.2.1 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
5.2.1.1 + 5V input 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 UC864-E, 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 electrical circuit
from power polarity inversion.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 19 of 51
An example of linear regulator with 5V input is:
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
5.2.1.2 + 12V input 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 UC864-E.
• 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.
• 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. The same
consideration has to be applied to the voltage peaks that in a Car Application could rise to 100V.
• 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.
• A spike protection diode should be inserted close to the power input for Car applications, in order
to clean the supply from spikes.
• A protection diode should be inserted close to the power input, in order to save UC864-E from
power polarity inversion. This can be the same diode as for spike protection.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 20 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
An example of switching regulator with 12V input is in the below schematic (it is split in 2 parts):
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 21 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
5.2.1.3 Battery Source Power Supply Design Guidelines
• The desired nominal output for the power supply is 3.8V and the maximum voltage allowed is
4.2V, hence a single 3.7V Li-Ion cell battery type is suited for supplying the power to the Telit
UC864-E module.
• The three cells Ni/Cd or Ni/MH 3.6 V Nom. battery types or 4V PB types MUST NOT BE
DIRECTLY USED since their maximum voltage can rise over the absolute maximum voltage for
UC864-E and damage it.
NOTE: DON'T USE any Ni-Cd, Ni-MH, and Pb battery types directly connected with UC864-E. Their use can
lead to overvoltage on UC864-E 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.
• 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 UC864-E 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.
5.2.1.4 Battery Charge control Circuitry Design Guidelines
The charging process for Li-Ion Batteries can be divided into 4 phases:
• Qualification and trickle charging
• Fast charge 1 - constant current
• Final charge - constant voltage
• Maintenance charge
The qualification process consists in a battery voltage measure, indicating roughly its charge status. If
the battery is deeply discharged, that means its voltage is lower than the trickle charging threshold,
then the charge must start slowly possibly with a current limited pre-charging process keeping the
current very low respect to the fast charge value: the trickle charging.
During the trickle charging the voltage across the battery terminals rises; when it reaches the fast
charge threshold level the charging process goes into fast charge phase.
During the fast charge phase the process proceeds with a current limited charging; this current limit
depends the complete charge required time and from the battery pack capacity. During this phase the
voltage across the battery terminals still raises but at a lower rate.
Once the battery voltage reaches its maximum voltage then the process goes into its third state: Final
charging. The voltage measure to change the process status into final charge is very important. It
must be ensured that the maximum battery voltage is never exceeded, otherwise the battery may be
damaged and even explode. Moreover regarding the constant voltage final chargers, the constant
voltage phase (final charge) must not start before the battery voltage has reached its maximum value;
otherwise the battery capacity will be highly reduced.
The final charge is done using constant voltage.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 22 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
The constant voltage charge proceeds with a fixed voltage regulator (very accurately set to the
maximum battery voltage) and hence the current will decrease while the battery is becoming charged.
When the charging current falls below a certain fraction of the fast charge current value, then the
battery is considered fully charged, the final charge stops and eventually starts the maintenance.
The last phase is not properly a charging phase, since the battery at this point is fully charged and the
process may stop after the final charge. The maintenance charge provides an additional charging
process to compensate for the typical Li-Ion battery charge leak. It is done by issuing pulses with a
fixed time length, again few hundreds of ms, and a duty-cycle around 5% or less.
This last phase is not implemented in the UC864-E internal charging algorithm, so that the battery
once charged is left discharging down to a certain threshold so that it is cycled from full charge to
slight discharge even if the battery charger is always inserted. This guarantees that anyway the
remaining charge in the battery is a good percentage and that the battery is not damaged by keeping it
always fully charged (Li-Ion rechargeable battery usually deteriorates when kept fully charged).
Last but not least, in some applications it is highly desired that the charging process restarts when the
battery is discharged and its voltage drops below a certain threshold, UC864-E internal charger does
it.
As you can see, the charging process is not a trivial task to be done; moreover all these operations
should start only if battery temperature is inside a charging range, usually +5°C ÷ +45°C.
In order to satisfy this last requirement, the UC864-E measures the temperature of its internal
components even if it is not exactly the same as the battery temperature; but in common application
the two temperatures should not differ too much and the charging temperature range should be
guaranteed.
NOTE: All voltage thresholds are provided, inside UC864-E, in order to maximize Li-Ion battery
performances and do not need to be changed.
NOTE: In this application the battery charger input current must be limited to less than 400mA. This can
be done by using a current limited wall adapter as the power source.
NOTE: When starting the charger from Module powered off the startup will be in CFUN4; to activate the
normal mode the command AT+CFUN=1 has to be provided.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 23 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
5.2.2 Thermal Design Guidelines
The thermal design for the power supply heat sink should be done with the following specifications:
• Average current consumption during WCDMA transmission @PWR level max: 620mA
• Average current consumption during class12 GPRS transmission @PWR level max: 930mA
NOTE: The average consumption during transmissions depends on the power level at which the device is requested
to transmit by the network. The average current consumption hence varies significantly.
Considering the very low current during idle, especially if Power Saving function is enabled, it is
possible to consider from the thermal point of view that the device absorbs current significantly only
during calls.
If we assume that the device stays into transmission for short periods of time (let's say few minutes)
and then remains for a quite long time in idle (let's say one hour), then the power supply has always
the time to cool down between the calls and the heat sink could be smaller than the calculated one for
930mA maximum RMS current, or even could be the simple chip package (no heat sink).
Moreover in the average network conditions the device is requested to transmit at a lower power level
than the maximum and hence the current consumption will be less than the 930mA, being usually
around 150mA.
For these reasons the thermal design is rarely a concern and the simple ground plane where the
power supply chip is placed can be enough to ensure a good thermal condition and avoid overheating.
For the heat generated by the UC864-E, you can consider it to be during transmission 1W max during
CSD/VOICE calls and 2W max during class12 GPRS upload.
This generated heat will be mostly conducted to the ground plane under the UC864-E; you must
ensure that your application can dissipate it.
In the WCDMA mode, since UC864-E emits RF signals continuously during WCDMA transmission,
you should pay special attention on how to dissipate the heat generated.
The current consumption will be up to about 620mA continuously at the maximum TX output power
(24dBm). Thus, you should arrange the PCB area as large as possible under UC864-E, which you will
mount. You can mount UC864-E on the large ground area of your application board and make many
ground vias for heat sink.
The peak current consumption in the GSM mode is higher than that in WCDMA. However, considering
the heat sink is more important with WCDMA.
As mentioned before, GSM signal is bursty. Thus, the temperature drift is more insensible than
WCDMA. Consequently, if you prescribe the heat dissipation in the WCDMA mode, you don’t need to
think more about the GSM mode
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 24 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
5.2.3 Power Supply PCB layout Guidelines
As seen on the electrical design guidelines the power supply shall have a low ESR capacitor on the
output to cut the current peaks and a protection diode on the input to protect the supply from spikes
and polarity inversion. The placement of these components is crucial for the correct working of the
circuitry. A misplaced component can be useless or can even decrease the power supply
performances.
• The Bypass low ESR capacitor must be placed close to the Telit UC864-E power input pads or in
the case of a switching power supply it can be placed close to the inductor to cut the ripple
provided the PCB trace from the capacitor to UC864-E is wide enough to ensure a drop-less
connection even during the 2A current peaks.
• The protection diode must be placed close to the input connector where the power source is
drained.
• The PCB traces from the input connector to the power regulator IC must be wide enough to ensure
no voltage drops occur when the 2A current peaks are absorbed. Note that this is not made in
order to save power loss but especially to avoid the voltage drops on the power line at the current
peaks frequency of 216 Hz that will reflect on all the components connected to that supply,
introducing the noise floor at the burst base frequency. For this reason while a voltage drop of 300400 mV may be acceptable from the power loss point of view, the same voltage drop may not be
acceptable from the noise point of view. If your application doesn't have audio interface but only
uses the data feature of the Telit UC864-E, then this noise is not so disturbing and power supply
layout design can be more forgiving.
• The PCB traces to UC864-E and the Bypass capacitor must be big enough to ensure no
significant voltage drops occur when the 2A current peaks are absorbed. This is for the same
reason as previous point. Try to keep this trace 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 switching power supply). This is done in order to reduce the radiated field (noise) at the
switching frequency (100÷500 usually).
• The use of a good common ground plane is suggested.
• The placement of the power supply on the board should be done in such a way to guarantee that
the high current return paths in the ground plane are not overlapped to any noise sensitive circuitry
as the microphone amplifier/buffer or earphone amplifier.
• The power supply input cables should be kept separate from noise sensitive lines such as
microphone/earphone cables.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 25 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
6 Antenna
The antenna connection and board layout design are the most important part in the full product design
and they strongly reflect on the product overall performances, hence read carefully and follow the
requirements and the guidelines for a proper design.
6.1 Antenna Requirements
As suggested on the Product Description the antenna for a Telit UC864-E device shall fulfill the
following requirements:
ANTENNA REQUIREMENTS
Frequency range
Bandwidth
GainImpedanceInput power
VSWR absolute maxVSWR recommended
Depending by frequency band(s) provided by the network operator, the customer shall use the most suitable antenna for that/those band(s) 70 MHz in GSM850, 80 MHz in GSM900, 170 MHz in DCS & 140 MHz PCS 250 MHz in WCDMA2100 bandGain < 3dBi 50 ohm> 33dBm(2 W) peak power in GSM > 24dBm Average power in WCDMA2100 <= 10:1<= 2:1
Furthermore if the device is developed for the US market and/or Canada market, it shall comply with
the FCC and/or IC approval requirements:
This device is to be used only for mobile and fixed applications. The antenna(s) used for this
transmitter must be installed to provide a separation distance of at least 20 cm from all persons and
must not be co-located or operating in conjunction with any other antenna or transmitter. End-Users
must be provided with transmitter operation conditions for satisfying RF exposure compliance. OEM
integrators must ensure that the end user has no manual instructions to remove or install the UC864-E
module. Antennas used for this OEM module must not exceed 3dBi gain for mobile and fixed
operating configurations.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 26 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
6.2 Antenna - Installation Guidelines
• Install the antenna in a place covered by the GSM/WCDMA signal.
• The Antenna must be installed to provide a separation distance of at least 20 cm from all persons
and must not be co-located or operating in conjunction with any other antenna or transmitter;
• Antenna shall not be installed inside metal cases
• Antenna shall be installed also according Antenna manufacturer instructions.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 27 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
7 Logic level specifications
Where not specifically stated, all the interface circuits work at 2.6V CMOS logic levels. The following
table shows the logic level specifications used in the Telit UC864-E interface circuits:
For 2.6V CMOS signals:
Absolute Maximum Ratings -Not Functional
Parameter
Input level on any
digital pin when on
Input voltage on
analog pins when on
Operating Range - Interface levels
Level
Input high level 2.0V 2.9 V
Input low level -0.3V 0.6V
Output high level 2.2V 2.6V
Output low level 0V 0.35V
For 1.8V signals:
Operating Range - Interface levels (1.8V CMOS)
Level
Input high level 1.5V 2.1V
Input low level -0.3V 0.5V
Output high level 1.4V 1.8V
Output low level 0V 0.35V
UC864-E
Min Max
-0.3V +3.0V
-0.3V +3.0 V
UC864-E
Min Max
UC864-E
Min Max
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 28 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
7.1 Reset signal
Signal Function I/O PIN Number
RESET Phone reset I 54
RESET is used to reset the UC864-E module. Whenever this signal is pulled low, UC864-E is reset.
When the device is reset it stops any operation. After the release of the reset UC864-E is
unconditionally shut down, without doing any detach operation from the network where it is registered.
This behavior is not a proper shut down because any device is requested to issue a detach request on
turn off. For this reason the Reset signal must not be used to normally shutting down the device, but
only as an emergency exit in the rare case the device remains stuck waiting for some network
response.
The RESET is internally controlled on start-up to achieve always a proper power-on reset sequence,
so there's no need to control this pin on start-up. It may only be used to reset a device already on that
is not responding to any command.
NOTE: do not use this signal to turn off the UC864-E. Use the ON/OFF signal to perform this function or
the AT#SHDN command.
Reset Signal Operating levels:
Signal Min Max
RESET Input high 2.0V* 2.2V
RESET Input low 0V 0.2V
* This signal is internally pulled up so the pin can be left floating if not used.
If unused, this signal may be left unconnected. If used, then it must always be connected with an open collector transistor, to permit to the internal circuitry the power on reset and under voltage
lockout functions.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 29 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
8 Serial Ports
The serial port on the Telit UC864-E is the interface between the module and OEM hardware.
2 serial ports are available on the module:
• MODEM SERIAL PORT
• MODEM SERIAL PORT 2 (DEBUG)
8.1 MODEM SERIAL PORT
Several configurations can be designed for the serial port on the OEM hardware, but the most
common are:
• microcontroller UART @ 5V or other voltages different from 2.8V
Depending from the type of serial port on the OEM hardware a level translator circuit may be needed
to make the system work. The only configuration that doesn't need a level translation is the 2.6V
UART.
The serial port on UC864-E is a +2.6V UART with all the 7 RS232 signals. It differs from the PCRS232 in the signal polarity (RS232 is reversed) and levels. The levels for UC864-E UART are the
CMOS levels:
Absolute Maximum Ratings - Not Functional
Parameter
Input level on any
digital pin when on
Input voltage on
analog pins when on
Operating Range - Interface levels
Level
Input high level 2.0V 2.9 V
Input low level -0.3V 0.6V
Output high level 2.2V 2.6V
Output low level 0V 0.35V
UC864-E
Min Max
-0.3V +3.0V
-0.3V +3.0 V
UC864-E
Min Max
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 30 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
The signals of the UC864-E serial port are:
RS232
Pin
Number
1 DCD
2 RXD
3 TXD
4 DTR
5 GND 5,6,7 Ground Ground
6 DSR
7 RTS
8 CTS
9 RI
Signal
dcd_uart
tx_uart
rx_uart
dtr_uart
dsr_uart
rts_uart
cts_uart
ri_uart
UC864-E
Pad
Number
32 Data Carrier Detect Output from the UC864-E that indicates the
26 Transmit line *see NoteOutput transmit line of UC864-E UART
25 Receive line *see NoteInput receive of the UC864-E UART
29 Data Terminal Ready Input to the UC864-E that controls the DTE
27 Data Set Ready Output from the UC864-E that indicates the
31 Request to Send Input to the UC864-E that controls the
28 Clear to Send Output from the UC864-E that controls the
30 Ring Indicator Output from the UC864-E that indicates the
Name Usage
carrier presence
READY condition
module is ready
Hardware flow control
Hardware flow control
incoming call condition
NOTE: According to V.24, RX/TX signal names are referred to the application side, therefore on
the UC864-E side these signal are on the opposite direction: TXD on the application side will be
connected to the receive line (here named TXD/ rx_uart ) of the UC864-E serial port and vice
versa for RX.
TIP: For a minimum implementation, only the TXD and RXD lines can be connected, the other
lines can be left open provided a software flow control is implemented.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 31 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
8.2 RS232 level translation
In order to interface the Telit UC864-E with a PC com port or a RS232 (EIA/TIA-232) application a
level translator is required. This level translator must
Invert the electrical signal in both directions
Translate the level from 0/2.6V to +15/-15V
Actually, the RS232 UART 16450, 16550, 16650 & 16750 chipsets accept signals with lower levels on
the RS232 side (EIA/TIA-562), allowing for a lower voltage-multiplying ratio on the level translator.
Note that the negative signal voltage must be less than 0V and hence some sort of level translation is
always required.
The simplest way to translate the levels and invert the signal is by using a single chip level translator.
There are a multitude of them, differing in the number of driver and receiver and in the levels (be sure
to get a true RS232 level translator not a RS485 or other standards).
By convention the driver is the level translator from the 0-2.6V UART level to the RS232 level, while
the receiver is the translator from RS232 level to 0-2.6V UART.
In order to translate the whole set of control lines of the UART you will need:
• 5 drivers
• 3 receivers
NOTE: The digital input lines working at 2.6V CMOS have an absolute maximum input voltage
of 3.0V; therefore the level translator IC shall not be powered by the +3.8V supply of the
module. Instead it shall be powered from a +2.6V / +2.9 (dedicated) power supply.
This is because in this way the level translator IC outputs on the module side (i.e. UC864-E
inputs) will work at +3.8V interface levels, stressing the module inputs at its maximum input
voltage.
NOTE: In order to be able to do in circuit reprogramming of the UC864-E firmware, the serial
port on the Telit UC864-E shall be available for translation into RS232 and either it's
controlling device shall be placed into tristate, disconnected or as a gateway for the serial data
when module reprogramming occurs.
Only RXD, TXD, GND and the On/off module turn on pad are required to the reprogramming of
the module, the other lines are unused.
All applicator shall include in their design such a way of reprogramming UC864-E.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 32 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
An example of level translation circuitry of this kind is:
The example is done with a SIPEX SP3282EB RS232 Transceiver that could accept supply voltages
lower than 3V DC.
NOTE: In this case Vin has to be set with a value compatible with the logic levels of the module
(Max 2.9V DC). In this configuration the SP3282EB will adhere to EIA/TIA-562 voltage levels
instead of RS232 (-5 +5V)
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 33 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
Second solution could be done using a MAXIM transceiver (MAX218)
In this case the compliance with RS232 (+-5V) is possible.
Another level adapting method could be done using a standard RS232 Transceiver (MAX3237EAI)
adding some resistors to adapt the levels on the UC864 Input lines.
NOTE: In this case has to be taken in account the length of the lines on the application to avoid
problems in case of High-speed rates on RS232.
The RS232 serial port lines are usually connected to a DB9 connector with the following layout:
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 34 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
5V UART level translation
If the OEM application uses a microcontroller with a serial port (UART) that works at a voltage different
from 2.6 – 2.9V, then a circuitry has to be provided to adapt the different levels of the two sets of
signals. As for the RS232 translation there are a multitude of single chip translators. For example a
possible translator circuit for a 5V TRANSMITTER/RECEIVER can be:
TO TELIT
MODULE
TIP: This logic IC for the level translator and 2.6V pull-ups (not the 5V one) can be powered directly from PWRMON
line of UC864-E. Note that the TC7SZ07AE has open drain output; therefore the resistor R2 is mandatory.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 35 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
NOTE: The UART input line TXD (rx_uart) of UC864-E is NOT internally pulled up with a resistor, so there may be the
need to place an external 47KΩ pull-up resistor, either the DTR (dtr_uart) and RTS (rts_uart) input lines are not
pulled up internally, so an external pull-up resistor of 47KΩ may be required.
A power source of the internal interface voltage corresponding to the 2.6V CMOS high level is
available at the PWRMON pin on the connector, whose absolute maximum output current is 1mA.
A maximum of 9 resistors of 47 KΩ pull-up can be connected to the PWRMON pin, provided no other
devices are connected to it and the pulled-up lines are UC864-E input lines connected to open
collector outputs in order to avoid latch-up problems on UC864-E.
Care must be taken to avoid latch-up on UC864-E and the use of this output line to power electronic
devices shall be avoided, especially for devices that generate spikes and noise such as switching level
translators, micro controllers, failure in any of these condition can severely compromise the UC864-E
functionality.
NOTE: The input lines working at 2.6VCMOS can be pulled-up with 47KΩ resistors that can be connected directly to
the PWRMON line provided they are connected as in this example.
NO OTHER devices than those suggested should be powered with the PWRMON line; otherwise the module
functionality may be compromised.
It is important to consider that the added circuit must have consumption lower than 1mA.
In case of reprogramming of the module has to be considered the use of the RESET line to start correctly the
activity.
The preferable configuration is having an external supply for the buffer.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 36 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
9 USB Port
UC864-E includes an integrated universal serial bus (USB) transceiver, compliant with USB 2.0
specification, for interfacing UC864-E to a computer as a USB peripheral or connecting the UC864-E
to other peripherals. It supports the USB low-speed (1.5 Mbits/s) and full-speed (12 Mb/s) modes. In
HSDPA (High Speed download Packet Access) mode, the downlink data speed rates up to 7.2Mbps.
Hence you need to interface UC864-E to your applications in full-speed (12Mbits/s) mode.
You can use USB for the following purposes: communication with external peripheral devices, debug
monitor
USB
Pin No.
1 USB_VBUS 48 Power supply for the internal USB transceiver. This pin is
2 USB_D- 80 Minus (-) line of the differential, bi-directional USB signal to/from
3 USB D+ 79 Plus (+) line of the differential, bi-directional USB signal to/from
4 USB_ID 35 Analog input used to sense whether a peripheral device is
NOTE: the UC864-E is turned fully on also by connecting the module’s USB port as slave (considering
also the presence of VBATT supply).
Signal UC864-E
Pad No.
Usage
configured as an analog input or an analog output depending
upon the type of peripheral device connected.
the peripheral device
the peripheral device
connected, and determine the peripheral type, a host or a slave
9.1 Communication ports combinations
The following port combinations are available on the UC864-E module:
• UART (AT command) +USB (DATA/TRACE)
• USB (AT command) + USB (DATA/TRACE)
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 37 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
10 Audio Section Overview
10.1 Generality
The UC864-E Audio Section provides two audio paths both in transmit and in receive sections, active
only one at time. Two buffering amplifiers could be used in Differential or Single Ended configuration.
To select the well-suited section, refer to paragraph 10.3 Selection mode.
For applications and suggestion refer to the Telit modules Audio Application Note (80000NT10007a)
10.2 Definitions
The Baseband chip was developed for the cellular phones, which needed a couple of amplifiers to be
used with internal audio transducers and another couple to be used with external ones , both in
transmit and in receive sections . Two different definitions were introduced to distinguish the
schematic signals and the Software identifiers, with the following meaning:
• HS or MTÆ internal audio transducers (from HandSet or MicroTelephone )
We have not changed the HS and HF acronyms with UC864-E, keeping them both in the Software
and on the schematics. But we want you to remember that if you don’t have any load driving constraint
(like a speaker with an impedance coil lower than 16Ω) this distinction is not relevant, because the two
sections:
• have fully equivalent electrical performances (like the two microphone amplifiers)
• activate the same functionalities (like the Echo Canceller module)
• offer slightly different performances (like the two speaker buffering stages)
Being the performances of the two blocks like the same in this case, the choice could be done as
example in order to overcome the PCB design difficulties, respecting the electrical characteristics.
10.3 Selection
The activation of the requested audio section is made Hardware by AXE line or Software by AT#CAP
command, turning on:
• an output stage to drive a low resistive load earpiece and an input stage to drive the local
microphone when AUDIO-1 mode (HS/MT) ;
• an output stage to drive a high resistive load headset and an input stage to drive the headset
microphone when AUDIO-2 mode (HF) .
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 38 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
10.4 Electrical Characteristics
10.4.1 Input lines (microphone)
The two transmit blocks are fully equivalent, connected in Differential mode
Line coupling AC (*)
Line type Balanced
Coupling capacitor ≥ 100nF
Differential input resistance 20kΩ
Differential input voltage ≤ 1,03Vpp @ HSMicG=0dB
Line coupling AC (*)
Line type Balanced
Coupling capacitor ≥ 100nF
Differential input resistance 20kΩ
Differential input voltage ≤ 1,03Vpp @ HFMicG=0dB
Due to the fact that particular OEM applications need a single line connection, a Single Ended
configuration could be
In both cases the OEM circuitries shall be carefully designed to reduce the common mode noise
typically generated on the ground plane.
In the previous tables, the line coupling definition AC (*) means that:
the signals from microphone must be connected to the input lines
of the UC864-E through CAPACITORS, not less than 100nF
Not respecting this constraint, the input stage will be damaged!
implemented, but halving the useful microphone signal.
WARNING
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 39 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
10.4.2 Output lines (speaker)
During designing, remember that while no difference could be if the amplifiers drive an external
amplifier, there are slightly different electrical performances when the load is driven directly from the
internal audio amplifiers, due to differential output voltage.
Line coupling DC
Line type Differential
Output load resistance 32 Ω
Max. Load capacitance 500pF(max)
Differential output impedance 1 Ω (max) @ 1.02KHz
Signal bandwidth 150 - 4000 Hz @ -3 dB
Differential output voltage @ 0dBm01.06 V
Number of volume steps 10
Volume level step -2dB
Table 3. “Ear_MT” Buffers
Line coupling DC
Line type Differential
Output load resistance 32 Ω
Max. load capacitance 500pF(max)
Differential output resistance 1 Ω (max) @ 1.02KHz
Signal bandwidth 150 - 4000 Hz @ -3 dB
Differential output voltage @ 0dBm0833mV
Number of volume steps 10 (SW)
Volume level step -2dB
Table 4. “Ear_HF” Buffers
We suggest to drive the load differentially from both receive drivers, thus the output swing is doubled
and the need for the output coupling capacitor is eliminated. However for particular OEM application
needs also a Single Ended circuitry can be implemented, but reducing by four the output power.
The OEM circuitry shall be designed to reduce the common mode noise typically generated on the
ground plane and to get the maximum power output from the device (low traces resistance).
Audio amplifiers could be design in two configurations: balanced (or differential) and unbalanced (or
single-ended).
The differential output power amplifier configuration is also called BTL (bridge-tied load).
In the following a discussion about the use of the two input and output amplifier configurations will be
dealt with.
Also calculation and circuit examples will be exhaustively performed.
rms
(typical)
rms
(typical)
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 40 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
11 General Purpose I/O
The general-purpose I/O pads can be configured to act in three different ways:
• Input
• Output
• Alternate function (internally controlled)
Input pads can only be read and report the digital value (high or low) present on the pad at the read
time; output pads can only be written or queried and set the value of the pad output; an alternate
function pad is internally controlled by the UC864-E firmware and acts depending on the function
implemented.
The following GPIO are available on the UC864-E module:
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 41 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
Not all GPIO pads support all these three modes:
• GPIO5 supports all three modes and can be input, output, RFTX monitor output (Alternate
function)
• GPIO6 supports all three modes and can be input, output, alarm output (Alternate function)
• GPIO7 supports all three modes and can be input, output, buzzer output (Alternate function)
11.1 Logic level specifications
Where not specifically stated, all the interface circuits work at 2.6V CMOS logic levels.
The following table shows the logic level specifications used in the UC864-E interface circuits:
Absolute Maximum Ratings -Not Functional
Parameter
Input level on any
digital pin when on
Input voltage on
analog pins when on
For 2.6V CMOS signals;
Operating Range - Interface levels
Level
Input high level 2.0V 2.9 V
Input low level -0.3V 0.6V
Output high level 2.2V 2.6V
Output low level 0V 0.35V
For 1.8V signals:
Operating Range - Interface levels (1.8V CMOS)
Level
Input high level 1.5V 2.1V
Input low level -0.3V 0.5V
Output high level 1.4V 1.8V
Output low level 0V 0.35V
UC864-E
Min Max
-0.3V +3.0V
-0.3V +3.0 V
UC864-E
Min Max
UC864-E
Min Max
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 42 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
11.2 Using a GPIO Pad as INPUT
The GPIO pads, when used as inputs, can be connected to a digital output of another device and
report its status, provided this device has interface levels compatible with the 2.6V CMOS levels of the
GPIO.
NOTE: If the digital output of the device to be connected with the GPIO input pad has interface levels
different from the 2.6V CMOS, it can be buffered with an open collector transistor, provided a 47KΩ
pull-up resistor is connected as seen in the paragraph 0
11.3 Using a GPIO Pad as OUTPUT
The GPIO pads, when used as outputs, can drive 2.6V CMOS digital devices or compatible hardware.
When set as outputs, the pads have a push-pull output and therefore the pull-up resistor may be
omitted.
11.4 Using the Alarm Output GPIO6
The GPIO6 pad, when configured as Alarm Output, is controlled by the UC864-E module and will rise
when the alarm starts and fall after the issue of a dedicated AT command.
This output can be used to power up the UC864-E controlling microcontroller or application at the
alarm time, giving you the possibility to program a timely system wake-up to achieve some periodic
actions and completely turn off either the application and the UC864-E during sleep periods,
dramatically reducing the sleep consumption to few μA.
In battery-powered devices this feature will greatly improve the autonomy of the device.
NOTE: During RESET the line is set to HIGH logic level.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 43 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
11.5 Using the Buzzer Output GPIO7
The GPIO7 pad, when configured as Buzzer Output, is controlled by the UC864-E module and will
drive with appropriate square waves a Buzzer driver.
This permits to your application to easily implement Buzzer feature with ringing tones or melody
played at the call incoming, tone playing on SMS incoming or simply playing a tone or melody when
needed by your application.
A sample interface scheme is included below to give you an idea of how to interface a Buzzer to the
GPIO7:
NOTE: To correctly drive a buzzer a driver must be provided, its characteristics depend on the Buzzer and for them
refer to your buzzer vendor.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 44 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
11.6 Indication of network service availability
The STAT_LED pin status shows information on the network service availability and Call status.
In the UC864-E modules, the STAT_LED usually needs an external transistor to drive an external
LED.
Therefore, the status indicated in the following table is reversed with respect to the pin status.
LED status DeviceStatus
Permanently off Device off
Fast blinking
(Period 1s, Ton 0,5s)
Slow blinking
(Period 3s, Ton 0,3s)
Permanently on a call is active
Net search / Not registered /
turning off
Registered full service
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 45 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
11.7 RTC Bypass out
The VRTC pin brings out the Real Time Clock supply, which is separate from the rest of the digital
part, allowing having only RTC going on when all the other parts of the device are off.
To this power output a backup capacitor can be added in order to increase the RTC autonomy during
power off of the battery.
Parameter Symbol Limit Values Unit
min. typ. max.
Input Voltage VRTC 1.50
3.0
3.25 V
Input current, Xtal ON IRTC
NOTE: NO Devices must be powered from this pin.
1.1 uA
11.8 VAUX1 power output
A regulated power supply output is provided in order to supply small devices from the module.
This output is active when the module is ON and goes OFF when the module is shut down.
The operating range characteristics of the supply are:
Operating Range – VAUX1 power supply
Min Typical Max
Output voltage
Output current
Output bypass capacitor
NOTE: During RESET and POWER ON the VAUX line is OFF
2.75V 2.85V 2.95V
100mA
2.2μF
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 46 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
11.9 Mounting UC864-E on your board
The position of the Molex board-to-board connector and the pin 1 are shown in the following picture.
NOTE: metal tabs present on UC864-E should be connected to GND
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 47 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
11.9.1 Debug of the UC864-E in production
To test and debug the mounting of the UC864-E, we strongly recommend to foreseen test pads on the
host PCB, in order to check the connection between the UC864-E itself and the application and to test
the performance of the module connecting it with an external computer.
Depending by the customer application, these pads include, but are not limited to the following signals:
• TXD
• RXD
• ON/OFF
• RESET
• GND
• VBATT
• TX_TRACE
• RX_TRACE
• PWRMON
• USB D+
• USB D-
• USB V_BUS
• USB_ID
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 48 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
12 Conformity Assessment Issues
The UC864-E module is assessed to be conforming to the R&TTE Directive as stand-alone products,
so if the module is installed in conformance with Dai Telecom installation instructions require no
further evaluation under Article 3.2 of the R&TTE Directive and do not require further involvement of a
R&TTE Directive Notified Body for the final product.
In all other cases, or if the manufacturer of the final product is in doubt then the equipment integrating
the radio module must be assessed against Article 3.2 of the R&TTE Directive.
In all cases assessment of the final product must be made against the Essential requirements of the
R&TTE Directive Articles 3.1(a) and (b), safety and EMC respectively, and any relevant Article 3.3
requirements.
The UC864-E moduleis conforming to the following European Union Directives:
• Low Voltage Directive 73/23/EEC and product safety
• Directive 89/336/EEC for conformity for EMC
In order to satisfy the essential requisite of the R&TTE 99/5/EC directive, the UC864-E module is
compliant with the following standards:
• Radio Spectrum, Standard: EN 301 511 and 3GPP 51.010-1
• EMC (Electromagnetic Compatibility). Standards: EN 301 489-1 and EN 301 489-7
• LVD (Low Voltage Directive) Standards: EN 60 950
In this document and the Hardware User Guide, Software User Guide all the information you may
need for developing a product meeting the R&TTE Directive is included.
The UC864-E moduleis conforming to the following US Directives:
• Use of RF Spectrum. Standards: FCC 47 Part 24 (GSM 1900)
• EMC (Electromagnetic Compatibility). Standards: FCC47 Part 15
To meet the FCC's RF exposure rules and regulations:
- The system antenna(s) used for this transmitter must be installed to provide a separation
distance of at least 20 cm from all the persons and must not be co-located or operating in
conjunction with any other antenna or transmitter.
- The system antenna(s) used for this module must not exceed 3 dBi for mobile and fixed or mobile
operating configurations.
- Users and installers must be provided with antenna installation instructions and transmitter
operating conditions for satisfying RF exposure compliance.
Manufacturers of mobile, fixed or portable devices incorporating this module are advised to clarify
any regulatory questions and to have their complete product tested and approved for FCC
compliance.
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 49 of 51
UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
13 SAFETY RECOMMANDATIONS
READ CAREFULLY
Be sure the use of this product is allowed in the country and in the environment required. The use of
this product may be dangerous and has to be avoided in the following areas:
Where it can interfere with other electronic devices in environments such as hospitals, airports,
aircrafts, etc.
Where there is risk of explosion such as gasoline stations, oil refineries, etc.
It is responsibility of the user to enforce the country regulation and the specific environment regulation.
Do not disassemble the product; any mark of tampering will compromise the warranty validity.
We recommend following the instructions of the hardware user guides for a correct wiring of the
product. The product has to be supplied with a stabilized voltage source and the wiring has to be
conforming to the security and fire prevention regulations.
The product has to be handled with care, avoiding any contact with the pins because electrostatic
discharges may damage the product itself. Same cautions have to be taken for the SIM, checking
carefully the instruction for its use. Do not insert or remove the SIM when the product is in power
saving mode.
The system integrator is responsible of the functioning of the final product; therefore, care has to be
taken to the external components of the module, as well as of any project or installation issue,
because the risk of disturbing the GSM network or external devices or having impact on the security.
Should there be any doubt, please refer to the technical documentation and the regulations in force.
Every module has to be equipped with a proper antenna with specific characteristics. The antenna has
to be installed with care in order to avoid any interference with other electronic devices and has to
guarantee a minimum distance from the body (20 cm). In case of this requirement cannot be satisfied,
the system integrator has to assess the final product against the SAR regulation.
The European Community provides some Directives for the electronic equipments introduced on the
market. All the relevant information’s are available on the European Community website:
The text of the Directive 99/05 regarding telecommunication equipments is available, while the
applicable Directives (Low Voltage and EMC) are available at: