GC864 Hardware User Guide GC864-PY, GC864-QUAD 1vv0300733 Rev.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 Contents 1 Overview ...........................................................................................................................4 2 Hardware Commands ......................................................................................................5 2.1 Turning ON the GC864 ...........................................................................................................5 2.2 Turning OFF the GC864 .....................
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 7.5 Microphone buffering...........................................................................................................37 7.5.1 7.5.2 8 OUTPUT LINES (Speaker)..............................................................................................42 8.1 Short description..................................................................................................................42 8.2 Output lines characteristics . .........
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 1 Overview The aim of this document is the description of some hardware solutions useful for developing a product with the Telit GC864 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.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 2 Hardware Commands 2.1 Turning ON the GC864 To turn on the GC864 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: don't use any pull up resistor on the ON# line, it is internally pulled up.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 For example: 1- Let's assume you need to drive the ON# pad with a totem pole output of a +3/5 V microcontroller (uP_OUT1): 2- Let's assume you need to drive the ON# pad directly with an ON/OFF button: Reproduction forbidden without Telit Communications S.p.A.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 2.2 Turning OFF the GC864 The turning off of the device can be done in three ways: • by software command (see GC864 Software User Guide) • by hardware shutdown 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. 2.2.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 TIP: The unconditional hardware reboot should be always implemented on the boards and software should use it as an emergency exit procedure. For example: 1- Let's assume you need to drive the RESET# pad with a totem pole output of a +3/5 V microcontroller (uP_OUT2): Reproduction forbidden without Telit Communications S.p.A.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 3 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. 3.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 3.2 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. 3.2.1 Electrical design Guidelines The electrical design of the power supply depends strongly from the power source where this power is drained.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 An example of linear regulator with 5V input is: Reproduction forbidden without Telit Communications S.p.A.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 3.2.1.2 + 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 the GC864.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 3.2.1.3 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 GC864 module. The three cells Ni/Cd or Ni/MH 3,6 V Nom. battery types or 4V PB types MUST NOT BE USED DIRECTLY since their maximum voltage can rise over the absolute maximum voltage for the GC864 and damage it.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 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 pulsed charge process has no voltage regulation, instead the charge continues with pulses.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 3.2.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 3.2.3 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.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 4 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. 4.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 4.3 Antenna installation Guidelines • • • • Install the antenna in a place covered by the GSM 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.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 5 GC864 pins allocation The GC864 uses an 80 pin Molex p.n. 53949-0878 male connector for the connections with the external applications. This connector matches the 54150-0878 model.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 Pin Signal I/O Function Internal Pull up Type 27 C107/DSR O Output for Data set ready signal (DSR) to DTE CMOS 2.8V 28 C106/CTS O Output for Clear to send signal (CTS) to DTE CMOS 2.8V 29 C108/DTR I Input for Data terminal ready signal (DTR) from DTE CMOS 2.8V 30 C125/RING O Output for Ring indicator signal (RI) to DTE CMOS 2.8V 31 C105/RTS I Input for Request to send signal (RTS) from DTE CMOS 2.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 Pin Signal I/O Function Internal Pull up Type 67 TGPIO_08 / CAM_ON I/O Telit GPIO8 Configurable GPIO / Camera Interface CMOS 2.8V 68 TGPIO_06 / ALARM I/O Telit GPIO6 Configurable GPIO / ALARM CMOS 2.8V 69 TGPIO_23 I/O CMOS 2.8V 70 TGPIO_01 I/O Reserved to detect ON/OFF. It is physically connected to pin 49 (PWRMON) Telit GPIO1 Configurable GPIO 71 TGPIO_17 I/O Telit GPIO17 GPIO pin CMOS 2.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 6 Serial Port The serial port on the Telit GC864 is the core of the interface between the module and OEM hardware. Several configurations can be designed for the serial port on the OEM hardware, but the most common are: - RS232 PC com port - microcontroller UART @ 2.8V - 3V (Universal Asynchronous Receive Transmit) - microcontroller UART@ 5V or other voltages different from 2.
GC864 Hardware User Guide 1vv0300733 Rev.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 6.1 RS232 level translation In order to interface the Telit GC864 with a PC com port or a RS232 (EIA/TIA-232) application a level translator is required.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 An example of level translation circuitry of this kind is: the RS232 serial port lines are usually connected to a DB9 connector with the following layout: Reproduction forbidden without Telit Communications S.p.A.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 6.2 5V UART level translation If the OEM application uses a microcontroller with a serial port (UART) that works at a voltage different from 2.8 - 3V, 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, but since the translation requires very few components, then also a discrete design can be suited.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 NOTE: The UART input line TXD (rx_uart) of the GC864 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.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 7 Audio Section Overview The Base Band Chip of the GC864 Telit Module provides two different audio blocks; both in transmit (Uplink) and in receive (Downlink) direction: “MT lines” should be used for handset function, “HF lines” is suited for hands -free function (car kit). These two blocks can be active only one at a time, selectable by AXE hardware line or by AT command.
50cm 7cm -45dBV/Pa -45dBV/Pa +10dB 3,3mV 0,33mV Reproduction forbidden without Telit Communications S.p.A. written authorization - All Right reserved GC864 Audio Paths +20dB 23mV rms 365mV rms Mic_HF- Mic_HF+ Mic_MT- Mic_MT+ GC864 Ear_HF- Ear_HF+ Ear_MT- Ear_MT+ ended Single Balance Fully Differential Power Buffers 16 16 -12dBFS egolite.sk 8 Differential Line-Out Drivers GC864 Hardware User Guide 1vv0300733 Rev.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 7.1 Microphone paths characteristic and requirements TIP: being the microphone circuitry the more noise sensitive , its design and layout must be done with particular care. Both microphone paths are balanced and the OEM circuitry should be balanced designed to reduce the common mode noise typically generated on the ground plane. However also an unbalanced circuitry can be used for particular OEM application needs .
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 TIP: definition of the nominal sensitivity of the microphone lines . The nominal sensitivity of the microphone lines indicates the voltage level on the GC864 pins present during "normal spoken" conditions. For a handset , the "normal spoken” conditions take place when the talker mouth is 7cm far from the microphone ; under these conditions the voice will produce an acoustic pressure of -4,7dBPa @1kHz on the microphone membrane .
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 TIP: environment consideration . For hands-free/car kit microphone, you must take into account the voice attenuation, due to the distance between the microphone itself and the talker, when designing the external microphone amplifier.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 7.2 General Design Rules There are several configurations for the audio paths, but the most effective difference is between balanced and unbalanced microphone configuration. It is highly recommended to keep the whole microphone path balanced even if this means having 2 wires connecting the microphone instead of one needed (plus ground) in the unbalanced case.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 7.4 Microphone Biasing The electret microphones usually need a biasing voltage to work properly. Refer to your microphone provider for the characteristics required. NOTE: The microphones have a hot wire were the positive biasing must be connected. Usually it is indicated by a + symbol or a red point. If the polarity of the bias is reversed, then the microphone will not work properly. For this reason be sure to respect the mic. biasing polarity. 7.4.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 NOTE: The cable to the microphone should not be shielded, instead a twisted pair cable shall be used. NOTE: The microphone sensitivity changes with the value of R2 and R3. Usually the microphones are characterized with 2kΩ biasing resistance, so try to keep the sum of R2 and R3 around 2kΩ. Refer to your microphone manufacturer for the mic. characteristics. 7.4.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 NOTE: In the unbalanced application the capacitor C3 shall be > 200nF otherwise the frequency response will be cut at low band frequencies (down to 300Hz). This capacitor can be placed close to the MIC- pad (MIC_HF- or MIC_MT- depending on the audio path chosen) or if possible it should be placed close to the shielded cable connector.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 7.5 Microphone buffering As seen previously, a microphone shall be connected to the input pins of the GC864 through a buffer amplifier that boosts the signal level to the required value. Again the buffered microphone circuitry can be balanced or unbalanced : where possible it is always preferable a balanced solution. The buffering circuit shall be placed close to the microphone or close to the microphone wire connector. 7.5.1 Buffered Balanced Mic.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 The buffer gain is given by the formula: Gain = R604 R606 = R605 R607 The C636 and C637 capacitors are placed in order to cut off the gain at higher frequencies than the transmitted GSM band, the cutoff frequency (-3dB) should be 3500Hz in order to have -1dB at 3kHz. The cutoff frequency is given by the formula: freq. = 1 1 = [Hz] 2π * R604 * C 637 2π * R606 * C 636 TIP: example of calculation .
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 7.5.2 Buffered Unbalanced (Single Ended) Microphone . MIC+ To GC864 2,7nF MIC+ 6,8nF The above schematic can be used for a single ended (buffered unbalanced) microphone; the required biasing circuitry is not included. Note also that the capacitor C3 is not needed .
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 1 1 freq. = = [Hz] 2π * R719 * C 726 2π * R711* C 727 The buffer bandwidth at -3dB shall be 4KHz. Note that the biasing of the operational amplifier is given for the inverting amplifier by the series divider R714-R715. The 100nF capacitor C719 is needed to filter the noise that could be coupled to that divider.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 As a consequence of the assigned values of the resistors, the nominal values of C726 and C727 are : C726= 1/ (2π*4000*R719)= 7.10 *10 -9 F C727= 1/ (2π*4000*R711)= 2,65 *10 -9 F modified in 6,8nF (fc1=4181Hz ) and 2,7nF (fc2=3931Hz) because of commercial values . Reproduction forbidden without Telit Communications S.p.A.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 8 OUTPUT LINES (Speaker) 8.1 Short description. The Telit GC864 provides two audio paths in receive section. Only one of the two paths can be active at a time, selectable by AXE hardware line or by AT command.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 8.2 Output lines characteristics . “Ear_MT” Differential Line-out Drivers Path • line coupling: • line type: • output load resistance : • internal output resistance: • signal bandwidth: • max.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 8.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 8.4 Handset earphone design As seen previously, a 16Ω earpiece can be directly connected to the output pads EAR_MT+ and EAR_MT- of the GC864. This solution is often the more cost effective, reducing the components count to a minimum.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 The resulting gain and high pass cut can be obtained with the formula: Gain = freq. = R3 R2 1 [Hz] 2π * R3 * C 4 And an example of internal Ear amplifier could be: +12dB GC864 Some amplifier require a low impedance load at high frequency in order to avoid auto oscillation, this can be made with a capacitor (100nF) in series with a resistor (15Ω).
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 8.6 Car Kit speakerphone design For the car kit speaker phone function the power output requirement is usually at least 4W, therefore an amplifier is needed to boost the GC864 output. The design of the amplifier shall comply with the following guidelines: • • • • • • The input to the amplifier MUST be taken from the “Ear_HF” audio path of the GC864, because of its echo canceller parameters suited to a car cabin use.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 9 External SIM Holder Aim of this section is to give basic design guide lines to integrate a SIM holder in applications that uses Telit modules 9.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 When connection is not short, insertion of 10..100ohm resistor with 10..33pF capacitor (RC filter) is a good caution to improve EMI from SIMCLK line. Do not insert resistor on SIMVCC, SIMRST and SIMIO lines, their use is not supported by SIM electrical interface. 3) ESD: take standard ESD caution if application based on TELIT module has SIM holder with contacts reachable from human body.
GC864 Hardware User Guide 1vv0300733 Rev.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 10.3 Using the Alarm Output GPIO_06/ALARM The GPIO_06/ALARM pad, when configured as Alarm Output, is controlled by the GC864 module and will rise when the alarm starts and fall after the issue of a dedicated AT command.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 11 Camera 11.1 Camera characteristics The GC864 module provides a direct support for digital cameras with the following characteristics: Type: Technology: Max picture size: Output format: Sensitivity: 11.1.1 TRANSCHIP TC5747 CMOS COLOR camera VGA 480x640 pixels landscape JPEG 4 Lux Camera interface connectors The 24-pads ZIF connector provides the interface connection between GC864 and camera.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 * - n.c - - 14 DOUT_7 I/O - n.c - - 15 DOUT_8 I/O - n.c - - 16 VCLKOUT O - n.c - - 17 VALIDH O - n.c - - 18 VALIDV O - VCC_MAIN_CAM O 19 DVDD28 I D7 CAM_SDA/IIC_SDA 20 SDIN I/O - GND - Ground 21 PS1 I K11 TGPIO_08/CAM_ON O Camera power type selector 22 PS2 I - GND - Ground 23 SHIELD - - - - Flash Enable 24 LED_CTRL O External 2.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 11.1.5 EVB for Transchip camera support In order to interface the Telit GC864 module with a CMOS camera, Telit has developed an evaluation board (see Annex B). The EVK2 (see Annex A) allow connecting all Telit modules through 2 connectors of 40 pins each. The I2CBUS CAMERA board is plugged in the 2 connectors of 30 pins each on the module board. CAMERA BOARD MODULE BOARD MAIN BOARD Reproduction forbidden without Telit Communications S.p.A.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 11.1.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 12 Conformity Assessment Issues The GC864 module is assessed to be conform 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.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 13 SAFETY RECOMMANDATIONS READ CAREFULLY Be sure the use of this product is allowed in the country and in the environment required.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 14 Document Change Log Revision ISSUE#0 Date 12/06/06 Changes Release First ISSUE# 0 Reproduction forbidden without Telit Communications S.p.A.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 Annex A – EVK2 schematics Reproduction forbidden without Telit Communications S.p.A.
GND R113 1 2 +3.7V D104 D CHARGE 2:9B SMB U34 4.7 G 5% 0603 11 PL106 STPS340U 6 Vcc R112 1 680 10 CHARGER ON 1 A 47K 4.7nF X7R 50V 0603 R105 4.7 BATTERY CHARGER INPUT 5% 1206 C105 5% 1206 2 9 9019915102410 2 R111 S 0 0 0603 1 + - CURRENT UNLIMITED R104 PL103 1984617PT1.5_2-3.5-H 8 3 R110 7 . TO-263AB IRL5602SPBF Q103 6 4.7 5 5% 1206 4 4.
1 2 3 4 5 6 7 8 9 10 11 A +3.
7 8 +3.7V U302 A ON-OFF* BYPASS 4 GND 26 28 C1+ L20A MA05A C305 GND C1- 47K 10uF 10V CONT-A 4 1 5% 0402 C2+ V- 3 GND U304 C2LDO_ON_OFF* 1:11B;6C;4:6E;5:2B;5:2D;5:8C V+ 25 R304 C306 15nF X7R 25V 0402 27 C316 2.2uF X5R 6.3V 0603 5 220nF X7R 10V 0603 3 V_OUT GND C312 C302 V_IN 11 220nF X7R 10V 0603 2 C309 1 10 C314 LP2982AIM5X-3_0-NOPB JP302 9 2.2uF X5R 6.
3 4 5 6 7 8 9 10 11 0 R411 C412 10pF COG 50V 0603 2 A 0 0603 1 0 noMount=YES +3.
3 4 5 3 C508 2 4 C503 27pF COG 50V 0402 CP12A 5 VCC 100nF X5R 10V 0402 GND 3 74AHC1GU04DCKRG4 3.3V_HUB R515 U506 LP2982AIM5X-3_3 3.3V_HUB noMount=YES GND 0 +5V_USB 5% 0402 15K R519 3.3V_HUB B ADBUS0 6 3V3OUT ADBUS1 5% 0402 5% 0402 USB HUB 27 5% 0402 1.
GC864 Hardware User Guide 1vv0300733 Rev. 0 - 12/06/06 Annex B - Camera EVB schematics Reproduction forbidden without Telit Communications S.p.A.
2 3 4 5 6 7 8 4773540103470 10 9 11 TRIZIUM GM862 1 SO109 A 3 2 1 SO101 SO102 4779723130417 4779723130417 1 PD[2] 5A 1 2 2 CAM_PWR_ON/AGILENT 6B SO107 4773540103470 3 TC5747MF24L 4 3 CAM_SYNC/AGILENT 5A 4 10D 5 MON1/CAM_CLK 3 2 1 5 TGPIO_08/CAM_ON 6 5D 6 5C 7 TGPIO_09/CAM_RST 9 DOUT2 DOUT3 DOUT4 DOUT5 DOUT6 DOUT7 DOUT8 VCLKOUT VALIDH VALIDV DVDD28 SDIN PS1 PS2 Shield LED_CTRL 0 0402 0 R115 CAM_M_CLK 10D;5A 0 0402 R107 18 19 19 20 20 21 21
TUTTI I DIRITTI RISERVATI RIPRODUZIONE E DIVULGAZIONE VIETATE ALL RIGHTS RESERVED REPRODUCTION AND DISCLOSURE FORBIDDEN MODIFY DATE PATH /Archivio_PCB/cs1170 FILE NAME cs1170 DESCRIPTION cs1170 I2CBUS DUAL CAMERA FILE GERBER ANNOTATION Mod. 048 Rev.0 6/99 Silkscreen side A Project by Drawn by: Pasqualini Natascia Verif. by FORM 06/09/2005 Project 0276 SHEET N. 1 A3 OF SHEETS DRAWING CODE 2 CS1170.
TUTTI I DIRITTI RISERVATI RIPRODUZIONE E DIVULGAZIONE VIETATE ALL RIGHTS RESERVED REPRODUCTION AND DISCLOSURE FORBIDDEN MODIFY DATE PATH /Archivio_PCB/cs1170 FILE NAME cs1170 DESCRIPTION cs1170 I2CBUS DUAL CAMERA FILE GERBER ANNOTATION Mod. 048 Rev.0 6/99 Silkscreen side B Project by Drawn by: Pasqualini Natascia Verif. by FORM 06/09/2005 Project 0276 SHEET N. 2 A3 OF SHEETS DRAWING CODE 2 CS1170.
