Telit Communications GM862-QUAD Hardware User's Manual

Cellular quad band module

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Telit Communications S.p.A. 2005

Telit GM862-QUAD/-QUAD-PY

Hardware User Guide

1vv0300692, Rev. ISSUE#0, - 04/10/2005

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Page 1 Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 Telit Communications S.p.A. 2005 page 1 of 69 Reproduction forbidden without DAI Telecom written authorization – All Right reserved – Right of modification reserved...
Page 2 Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 Contents OVERVIEW HARDWARE COMMANDS Turning ON the GM862-QUAD Turning OFF the GM862-QUAD 2.2.1.1 Hardware shutdown 2.2.1.2 Hardware Unconditional Reset POWER SUPPLY Power Supply Requirements General Design Rules 3.2.1 Electrical design Guidelines 3.2.1.1...
Page 3 Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 SPEAKER Speaker lines characteristics and requirements General Design rules 6.2.1 Noise Filtering Handset earphone design Hands Free earphone (low power) design Car Kit speakerphone design GENERAL PURPOSE I/O Using a GPIO pin as INPUT...
Page 4: Overview
PY Product Description document where all the hardware information is reported. NOTE: In this document all the hardware solution are referenced to the GM862-QUAD. As a general rule, since all the product line GM862-QUAD, GM862-QUAD-PY is pin to pin hardware compatible, all these solutions apply also to the GM862-QUAD-PY.
Page 5: Hardware Commands
2 Hardware Commands 2.1 Turning ON the GM862-QUAD To turn on the GM862-QUAD the pin ON# must be tied low for at least 1 second and then released. The maximum current that can be drained from the ON# pin is 0,1 mA.
Page 6 Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 For example: 1- Let's assume you need to drive the ON# pin with a totem pole output of a +3/5 V microcontroller (uP_OUT1): 2- Let's assume you need to drive the ON# pin directly with an ON/OFF button: page 6 of 69 Reproduction forbidden without DAI Telecom written authorization –...
Page 7: Turning Off The Gm862-Quad
2.2.1.1 Hardware shutdown To turn OFF the GM862-QUAD the pin ON# must be tied low for at least 1 second and then released. The same circuitry and timing for the power on shall be used.
Page 8 NOTE: don't 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 GM862-QUAD power regulator and improper functioning of the module. The line RESET# must be connected only in open collector configuration.
Page 9: Power Supply
3.1 Power Supply Requirements The GM862-QUAD power requirements are: • Nominal Supply Voltage: 3.8 V • Max Supply Voltage: 4.2 V...
Page 10: Electrical Design Guidelines
• A Bypass low ESR capacitor of adequate capacity must be provided in order to cut the current absorption peaks close to the GM862-QUAD, 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.
Page 11: V Input Source Power Supply Design Guidelines
A switching power supply will be preferable because of its better efficiency especially with the 2A peak current load represented by the GM862-QUAD. • When using a switching regulator, a 500Khz switching frequency regulator is preferable because of its smaller inductor size and its faster transient response.
Page 12: Battery Source Power Supply Design Guidelines
NOTE: DON'T USE any Ni-Cd, Ni-MH, and Pb battery types. Their use can lead to overvoltage on the GM862-QUAD and damage it. USE ONLY Rechargeable 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.
Page 13 5% or less. This last phase is not implemented in the GM862-QUAD 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.
Page 14: Thermal Design Guidelines
Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 An example of battery charger can be: NOTE: In this particular application the battery charger input current must be limited to less than 1A. This can be done by using a current limited wall adapter as the power source.
Page 15: Power Supply Pcb Layout Guidelines
If your application doesn't have audio interface but only uses the data feature of the Telit GM862-QUAD, then this noise is not so disturbing and power supply layout design can be more forgiving.
Page 16 Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 • 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.
Page 17: Serial Port
The only configuration that doesn't need a level translation is the 2.8V UART. The serial port on the GM862-QUAD is a +2.8V UART with all the 7 RS232 signals. It differs from the PC-RS232 in the signal polarity (RS232 is reversed) and levels. The levels for the GM862-...
Page 18 NOTE: According to V.24, RX/TX signal names are referred to the application side, therefore on the GM862-QUAD 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 GM862-QUAD serial port and viceversa for RX.
Page 19: Rs232 Level Translation
+2.8V / +3.0V (dedicated) power supply. This is because in this way the level translator IC outputs on the module side (i.e. GM862-QUAD inputs) will work at +3.8V interface levels, stressing the module inputs at its maximum input voltage.
Page 20 Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 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: page 20 of 69...
Page 21: V Uart Level Translation
Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 4.2 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 set of signals.
Page 22 GM862-QUAD. Care must be taken to avoid latch-up on the GM862-QUAD and the use of this output line to power electronic devices shall be avoided, especially for devices that generate spikes and noise such as level translators, digital ICs or microcontrollers, failure in any of these condition can severely compromise the GM862-QUAD functionality.
Page 23: Microphone
5.1 Microphone line Characteristic and requirements The Telit GM862-QUAD provides two audio paths for the microphone and the earpiece: the internal and the external audio paths. Only one of the two paths can be active at a time and it is selectable by hardware line AXE or by AT command.
Page 24 If the echo canceller is left active with the headset, then some echo might be introduced by the echo cancel algorithm. The nominal sensitivity of the line indicates the voltage level on the GM862-QUAD pins that should be present during "normal spoken" conditions: for a handset a voice signal coming from the mouth of the talker at 7 cm of distance from the microphone, producing an acoustic pressure of -4,7 (@ 1 kHz) on the microphone membrane.
Page 25 = 3.3* 10 by having the microphone gain set to +10 dB (corresponding to 3 times) the signal in the nominal conditions on the input external mic. pins of the GM862-QUAD will be: Voltage @ GM862-QUAD__extmic = 3.3 * 10 * 3 = 1 mV Hence in these conditions the signal level on the input pins of the external mic.
Page 26: General Design Rules
Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 5.2 General Design Rules There are several configurations for the audio path, but the most effective difference is between balanced and unbalanced microphone. 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.
Page 27: Balanced Microphone Biasing
Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 5.3.1 Balanced Microphone biasing The balanced microphone bias voltage should be obtained from a dedicated voltage regulator, in order to eliminate the noise present on the power lines. This regulator can be the same for all the audio paths.
Page 28: Unbalanced Microphone Biasing
Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 5.3.2 Unbalanced Microphone biasing The unbalanced microphone biasing voltage should be obtained from a dedicated voltage regulator, in order to eliminate the noise present on the power lines. This regulator can be the same for all the audio paths.
Page 29: Microphone Buffering
1vv0300692, Rev. ISSUE#0, - 04/10/2005 5.4 Microphone buffering As seen previously, a microphone shall be connected to the input pins of the GM862-QUAD 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 mic.
Page 30 Mic_Voltage_Output = 10 = 3.3* 10 in order to have a signal of 50 mV on the GM862-QUAD internal mic. inputs then the buffer must have a gain of: Voltage @ GM862-QUAD_intmic/ Mic_Voltage_Output = (50 * 10 )/( 3.3 * 10 ) = 15 Hence in these conditions the signal level on the input pins of the internal mic.
Page 31: Buffered Unbalanced (Single Ended) Mic
Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 5.4.2 Buffered Unbalanced (Single Ended) Mic. A sample schematic for a buffered unbalanced (single ended) microphone can be: The schematic does not include the required mic. biasing circuitry. For the biasing the same circuit as seen before can be used;...
Page 32 1 mV (10 dB lower than the nominal input for the GM862-QUAD external mic. path) on the GM862-QUAD internal mic. inputs then the buffer must have a gain of: Voltage @ GM862-QUAD_intmic/ Mic_Voltage_Output = (1 * 10 )/( 3.3 * 10...
Page 33 Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 As a consequence the values of the capacitors C726 and C727 shall be: C726= 1/ (2π*8000*R719)= 3.5 *10 C727= 1/ (2π*8000*R711)= 1,2 *10 The commercial values of 3.3nF and 1nF are then chosen.
Page 34: Speaker
6.1 Speaker lines characteristics and requirements The Telit GM862-QUAD provides two audio paths for both the microphone and the earpiece: the internal and the external audio paths. Only one of the two paths can be active at a time and it is selectable by hardware line AXE or by AT command.
Page 35 Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 • maximum power output: 7.5 mW • volume level steps (SW): - 2 dB • number of volume steps (SW): The EVK v.1.2 audio output characteristics are: internal/external ear single ended •...
Page 36: General Design Rules
The three groups have different power requirements, usually the first two applications need only few mW of power, which can be directly drained from the GM862-QUAD pins, provided a suited speaker is used. This direct connect design is the cheaper and simpler solution and will be suited for the most of the earphone design requirements.
Page 37 QUAD which is limited and for some particular applications may not be enough. For these reasons, when the power output of the GM862-QUAD is not enough or if the speaker characteristics are different from the suggested, then it is preferable to use an amplifier to increase the power and current output capabilities.
Page 38: Hands Free Earphone (Low Power) Design
The same design considerations made for the handset are valid for the hands free earphone, the only difference is that the external ear audio output level from the GM862-QUAD is 6dB lower than the internal one, so the gain of the amplifier must be 6dB higher to provide the same audio level.
Page 39 • The power to the amplifier should be decoupled as much as possible from the GM862-QUAD power supply, by either keeping separate wires and placing bypass capacitors of adequate value close to the amplifier power input pins.
Page 40: General Purpose I/O
Input pins can only be read and report the digital value (high or low) present on the pin at the read time; output pins can only be written or queried and set the value of the pin output; an alternate function pin is internally controlled by the GM862-QUAD firmware and acts depending on the function implemented.
Page 41: Using The Alarm Output Gpio6
1vv0300692, Rev. ISSUE#0, - 04/10/2005 7.3 Using the Alarm Output GPIO6 The GPIO6 pin, when configured as Alarm Output, is controlled by the GM862-QUAD module and will rise when the alarm starts and fall after the issue of a dedicated AT command.
Page 42: Camera
Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 8 Camera 8.1 Agilent Camera The GM862-QUAD provides a direct support for digital cameras with the following characteristics: Type: AGILENT ADCM2650 Technology: CMOS COLOR camera Max picture size: VGA 640x480 pixels...
Page 43 Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 CAM_DRDY Data ready in an output for the camera and an input for the GM862-QUAD CAM_PWR_ON O 2,8V power supply enable for the VCC_MAIN I camera Horizontal sync n.c. HSYNC...
Page 44: Evb For Camera Support
PC. To switch on the level translator a jumper shall be set on PL203. • 12 pin Berg male connector (PL202) to supply the GM862-QUAD mounted on the EVB. The input source power should be in the range 4,5V-12V. Charge line is also provided in case a Li- Ion battery is connected to the VBATT pins.
Page 45: Camera Transchip
Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 8.2 Camera Transchip The GM862-QUAD provides a direct support for Transchip digital cameras with the following characteristics: Type: TRANSCHIP TC5747 Technology: CMOS COLOR camera Max picture size: VGA 480x640 pixels landscape...
Page 46 Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 VCLKOUT VALIDH VALIDV GPIO7 External 2.8V Regulator enable DVDD28 controlled by CAM_PWR_ON pin CAM_PWR_ON GPIO4 I/O I2C bus serial data SDIN IICSDA_CAM 2-4-6 Ground GPIO8 Camera power type selector PD(0)
Page 47: Evb For Agilent And Transchip Camera Support
Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 8.2.2EVB for Agilent and Transchip camera support In order to interface the Telit GM862 with a CMOS camera, Telit has developed an evaluation board. The EVK allow connecting all Telit modules through 2 connectors of 40 pins each.
Page 48: Block Diagram For Supported Cameras
Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 8.2.3Block Diagram for supported cameras CAMERA TRANSCHIP CAMERA AGILENT PD[6] DVDD AVDD IICSDA_CAM PD[1] IICSCL_CAM CAM_CLK CAM_PWR_ON CAM_DRDY PD[7] PD[6] PD[5] PD[4] PD[3] PD[2] PD[1] PD[0] CAM_SYNC CAM_CLK DVDD IICSDA_CAM...
Page 49: Schematic Diagrams For Supported Cameras
Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 8.2.4 Schematic Diagrams for supported cameras page 49 of 69 Reproduction forbidden without DAI Telecom written authorization – All Right reserved – Right of modification reserved...
Page 50 Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 page 50 of 69 Reproduction forbidden without DAI Telecom written authorization – All Right reserved – Right of modification reserved...
Page 51: Example Usage Script For Camera
Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 8.2.5Example usage script for camera Camera setting: (shown here are the defaults ones) >AT#CAMSEL=0 (camera selection: 0-auto, 1-agilent, 2-transchip) >AT#CMODE=0 (camera mode: 0-day, 1-night) >AT#CAMQUA=0 (camera quality: 0-low, 1-medieum, 2-high) >AT#CAMRES=0...
Page 52: Document Change Log
Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 9 Document Change Log Revision Date Changes page 52 of 69 Reproduction forbidden without DAI Telecom written authorization – All Right reserved – Right of modification reserved...
Page 53: Annex A - Evk Schematics
Telit GM862-QUAD/-QUAD-PY Hardware User Guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 10 Annex A - EVK schematics page 53 of 69 Reproduction forbidden without DAI Telecom written authorization – All Right reserved – Right of modification reserved...
Page 54 WARNING!!!! Max current limit must be properly CURRENT UNLIMITED set for the size of battery in use BATTERY CHARGER INPUT C101 Keep max current around 1/2 of 4.7nF 6 Vcc battery pack capacity FCMM0502 E.g. 1000mAh -> 500 mA max SO104 0603 Curr.
Page 55 +5V input linear regulator U201 SO201 LT1528CQ FCMM0502 C201 +5V INPUT V_IN V_OUT 100uF 4,5V-8 Vcc SHDN* DZ201 D205 C203 C202 R202 6KA24 STPS140Z SENSE CONT-D 39nF 10uF GND_1 SOD123 6KA24 noMount=YES 0603 CONT-E 0603 R201 WARNING!!!! Care must be taken to ensure +5V/+12V select that the right polarity in the 0603...
Page 56 +3.7V PL302 1215061-02F RS232 LEVEL TRANSLATOR POWER SELECTION U301 ICL3207CA SSOP-24 TO RS232 SO301 L316 787200-1 LQG18HN39NJ00 L315 T1_OUT T1_IN 39nH LQG18HN39NJ00 004:6D L314 LQG18 T2_OUT T2_IN TX_PROG LQG18HN39NJ00 39nH 004:6D L313 LQG18 TR3_OUT T3_IN LQG18HN39NJ00 39nH 004:5D L312 LQG18 T4_OUT T4_IN LQG18HN39NJ00...
Page 57 L401 0.35 +3.7V 4312-020 noMount=YES L403 GM862 CONNECTOR BLM21 C405 C404 C403 C402 C401 L404 PL401 100nF 100pF 100nF 100pF 33pF 53748-0504 0603 0603 BLM21 0603 0603 0603 GND_EXT S1 CONNECTOR L402 0.35 SO402 4773541130470 4312-020 noMount=YES EAR_HF+ EAR_HF+ EAR_MT- EAR_MT- EAR_HF- EAR_HF-...
Page 58 +3.7V +3.7V R503 R510 0603 PL506 1215061-02F 0603 PLCC2 GPIO2 004:4D YELLOW 004:5D GREEN - GPIO2 LED GPIO2 OUTPUT LY-T670HK DL503 ON BUTTON +3.7V SW502 +3.7V Q506 BCR148W TC7S08FU SOT-323 SKHHAL C501 100nF U501 VCC_1 Q503 TC7S08FU BCR148W U501 GND_1 SOT-323 0603 +3.7V...
Page 59 BALANCED MICROPHONE POLARIZATION +3V_INT_MIC_BAL R601 BALANCED MICROPHONE BUFFER +24 dB 0603 DECOUPLING CAPACITORS Q601 BC847BW SOT-323 C601 +3V_INT_MIC_BAL 4.7uF +3V_INT_MIC_BAL R616 SO606 CONT-R J01001A1944 INT_MIC+ 0603 U602 TS3V912ID R602 SIGNAL FILTERING +3V_INT_MIC_BAL SO601 L602 0603 LGK2009-0201 C627 R615 LQG18HN39NJ00 PL603 BALANCED 100nF 1215061-03F...
Page 60 BALANCED MICROPHONE POLARIZATION +3V_EXT_MIC_BAL R705 0603 Q702 DECOUPLING CAPACITORS BC847BW BALANCED MICROPHONE BUFFER +10 dB SOT-323 C702 4.7uF +3V_EXT_MIC_BAL SO705 CONT-R R713 J01001A1944 +3V_EXT_MIC_BAL EXT_MIC+ 0603 +3V_EXT_MIC_BAL U702 R702 TS3V912ID PL702 1215061-03F +3V_MIC NOISE FILTERING 0603 +3V_EXT_MIC_SINGLE BALANCED SO701 L703 SINGLE ENDED LGK2009-0201 C718...
Page 61 INTERNAL EAR AMPLIFIER +6dB NOISE FILTERING SO801 U801 LGY6502-0600 L802 +3.7V LM4862M LQG18HN39NJ00 BRIDGED 39nH INTERNAL EAR EAR_MT+ LQG18 004:3D;006:10E SHUTDOWN LGY650X L801 BYPASS C821 C822 LQG18HN39NJ00 EAR_MT- 100nF 100nF 004:3D;006:10D C802 39nH LQG18 100nF C805 C806 C807 SO806 C804 C801 0603 0603...
Page 62 HIGH POWER EXT EAR AMPLIFIER (6W) +12V noMount=YES NOISE FILTERING R901 U901 TDA8943SF-N1 L902 SO901 0603 EAR_HF+ FCMM0502 BLM21 OUT- 004:3D;008:10D C913 R902 HIGH POWER BRIDGED 1.5nF EXTERNAL EAR L901 MIN 8 OHM 0603 0603 OUT+ EAR_HF- BLM21 004:3D;008:10D MODE C904 C905 C906...
Page 65: Annex B - Camera Evb Schematics
Telit GM862-QUAD Hardware User guide 1vv0300692, Rev. ISSUE#0, - 04/10/2005 11 Annex B - Camera EVB schematics Reproduction forbidden without DAI Telecom written authorization – All Right reserved – Right of modification reserved page 65 of 69...

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