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AL7020S Designer’s Guide
GSM Socket Modem
AL7020S, AL7020S-3V Series
Designer’s Guide
RELEASED 17. JANUARY 2005
Doc. No. DG_7020C Altec Electronic AG Seite 1 / 32
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AL7020S Designer’s Guide Information provided by Altec Electronic AG is believed to be accurate and reliable. However, no responsibility is assumed by Altec Electronic 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 Altec other than for circuitry embodied in Altec products. Altec Electronic r
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AL7020S Designer’s Guide Table of Contents 1. INTRODUCTION..........................................................................................................5 1.1 Models Description.......................................................................................................5 1.2 Summary......................................................................................................................5 1.3 Product Specifications.........................................
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AL7020S Designer’s Guide List of Tables & Figures Table 3-1. Serial TTL Signals...................................................................................................9 Table 3-2. Signal Descriptions ...............................................................................................10 Table 3-3. Signal Descriptions (Cont'd)..................................................................................11 Table 3-3. Signal Descriptions (Cont'd
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AL7020S Designer’s Guide 1. INTRODUCTION 1. INTRODUCTION 1.1 Models Description Models Operating Bands Interface Connectors Interfaces / Power • DIL-64 Header (RM2) • RS232 TTL Level AL7020S GSM 900/1800 MHz • MMCX RF Connector • 5 VDC Power • DIL-64 Header (RM2) • RS232 TTL Level AL7020S-3V GSM 900/1800 MHz • MMCX RF Connector • 3.3 VDC Power • RS232 TTL Level • DIL-64 Header (RM2) AL7020S-ES GSM 900/1800 MHz • SIM Card Interface • MMCX RF Connector • 5 VDC Power • DIL-64
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AL7020S Designer’s Guide 1.3 Product Specifications Product Features Voice Functions Operating EGSM: 900/1800 MHz Telephony systems: GSM: 850/1900 MHz Digital audio Differential analog audio lines Physical Characteristics Vocoders EFR/ER/FR/AMR DTMF support 64.5 x 26.5 mm Socket Size: Audio control: echo cancellation, noise Modem Form Faktor suppression, side tone and gain control Mounting: Through DIL-64 connectors GSM Supplementary Services Weight: US
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AL7020S Designer’s Guide 2. TECHNICAL OVERVIEW 2. TECHNICAL OVERVIEW 2.1 Block Diagramm of GSM Module 2.2 Supported Interfaces The major hardware signal interfaces of the DF Series SocketGSM Modem are illustrated in Figure 1-1. 5 TTL Antenna 1 3 Serial Interface interface Socket 3 GSM External SIM (Optional) Modem 1 1 Module Speaker Microphone 1 2 Leds Interface Figure 2-1. Interface Block Diagram
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AL7020S Designer’s Guide 3. HARDWARE INTERFACE 3. HARDWARE INTERFACE 3.1 Interface Signals The Socket Modem pin assignments with DTE serial TTL interface, SIM Card and Analog Interface are shown in Figure 3-1 and are listed in Table 3-1. 3.2 Signal Description The Socket Modem interface signals are described in Table 3-3. The digital electrical characteristics are listed in Table 3-4. The analog electrical characteristics are listed in Table 3-5.
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AL7020S Designer’s Guide 1 64 NC SPKR 2 63 NC GND POWER 62 MIC AUDIO 61 VCC Top View 24 41 RESET# GND 25 40 NC DTR# 26 39 SIM / LED GND DCD# SERIAL TTL 27 38 INTERFACE LED-GPRS CTS# INTERFACE 28 37 SIMVCC DSR# 29 36 GSM LED RI# 30 35 SIMDATA TXD# 31 34 SIMRST RXD# 32 33 SIMCLK RTS# Notes: Pins 3-23 and 42-60 are not installed. Figure 3-1. SERIAL PINOUT Table 3-1. Serial TTL Signals PI NAME I/O TYPE PIN NAME I/O TYPE
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AL7020S Designer’s Guide Table 3-2. Signal Descriptions Label I/O Type Signal Name/Description +5 VDC. A standard 5V +/- 5% - 1.5A power supply is strictly required to supply this module (5V Versions). Average current is 270mA (350mA @ PCL5). See also chapter 5.1.2 VCC PWR +3.-3 VDC. A standard 3.3V +/- 5% - 1A power supply is strictly required to supply this module (3V Versions). Average current is 270mA (350mA @ PCL5). See also chapter 5.1.3 GND GND Digital Ground Co
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AL7020S Designer’s Guide Table 3-3. Signal Descriptions (Cont'd) I/O Type Signal Name/Description Label The Serial interface signals are TTL-level signals. Request To Send (TTL Active Low). ~RTS is used to condition the local modem for data transmission and, during half-duplex operation, to control the direction of data transmission. On a full-duplex channel, RTS OFF maintains the modem in a non-transmit mode. A non-transmit mode does
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AL7020S Designer’s Guide Table 3-3. Signal Descriptions (Cont'd) Label I/O Type Signal Name/Description LED driver lines are open-drain inverter-driven (74HCT05) lines with 1.5 K Ω, 1/10W pull-up resistors. GSM activity LED. active low ! GSM LED OG connect LED to 5V with resistor in series. GPRS activity LED. active low ! GPRS LED OG connect LED to 5V with resistor in series. Audio/Headset Interface Microphone Voice Input. MICV is a single-ended microphone
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AL7020S Designer’s Guide Table 3-5. Digital Electrical Characteristics Parameter Symbol Min. Typ. Max. Units Test Conditions Input High Voltage V 2 - 5.5 Vdc IH pins 33,35,40 Input Low Voltage V 0 - 0.8 Vdc IL pins 33,35,40 Output High V VCC-0.1V VCC - Vdc ILOAD= -20 uA OH Voltage pins 34,36,37,38 3.8V 4.2 - ILOAD = -4 mA @VCC=4.5V Output High V OH Voltage VCC-0.1 VCC - ILOAD= -50 uA VCC=4.5V pin 39 3.8V - - ILOAD = -8 mA
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AL7020S Designer’s Guide Table 3-6. Absolute Maximum Ratings Parameter Symbol Min. Typ. Max. Units Test Condition Supply Voltage V Vdc DD -0.3 - +6.0 Input Voltage V Vdc IN -0.5 - +7.0 Nominal Supply Voltage V Vdc DD 5V Version 4.75 - 5.25 3V Version 3.20 - 3.45 Static Discharge Voltage V V ESD @ 25°C - +/- 2500 Operating Temperature Range T °C A Operational -20 - +60 Functional -20 - +
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AL7020S Designer’s Guide 3.4 Antenna Interface (RF) The AL7020S has two models, one for North America Frequency bands (850/1900 MHz), and one for European Bands (900/1800 MHz). The following connection requirements apply for the AL7020S antenna: • The AL7020S is terminated with an MMCX connector, and with 50-ohm impedance in the relevant frequencies. • The AL7020S can be connected to any antenna with 50-ohm impedance in the relevant frequency bands. • The AL7020S is designed to
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AL7020S Designer’s Guide 3.4.2 Antenna Performance Recommendations Table 3.7 - Antenna Performance Recommendations Frequencies: TX 824 – 849 MHz GSM 850 RX 869 – 893 MHz TX 880 – 915 MHz GSM 900 RX 925 – 960 MHz TX 1710 – 1785 MHz DCS 1800 RX 1805 – 1880 MHz TX 1850 - 1910 MHz PCS 1900 RX 1930 – 1990 MHz 0 dBi (unity) gain or Gain: greater Impedance: 50 Ohm Typical: 1.5:1 VSWR: Worst case: 2.5:1 3.4.3 Antenna Installation • A minimum separation distance of
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AL7020S Designer’s Guide 3.5 Internal SIM Card Interface The AL7020S module has a built-in SIM card reader within the module itself (see figure 3.5). The SIM card is inserted into the slot provided on the side of the connectors (bottom side). The SIM Interface controls a 3V SIM card. This interface is fully compliant with GSM 11.11 recommendation concerning SIM functions. 3.5.1 SIM Card reader pins supported: Signal Pin No I/O Description SIMVCC 1 O SIM Power Supply SIMRST
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AL7020S Designer’s Guide 3.6 SIM Card Mechanical Drawings Doc. No. DG_7020B Altec Electronic AG Seite 18 / 32
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AL7020S Designer’s Guide 3.7 External SIM Card Interface (-ES Option) 4 signals exist: • SIMVCC: SIM power supply. • SIMRST: reset. • SIMCLK: clock. • SIMDATA : I/O port. The SIM interface controls a 3V SIM. This interface is fully compliant with GSM 11.11 recommendations concerning SIM functions. It is recommended to add Transient Voltage Suppressor diodes on the signal connected to the SIM socket in order to prevent any Electrostatic Discharge. TVS diodes with low capacitance
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AL7020S Designer’s Guide 3.7.3 SIM Card Reader Integration: SIM interface controls a 3V SIM only. We add Transient Voltage Suppressor (TVS) diodes with low capacitance (less than 10pF) on signal connected to the SIM socket in order to prevent any Electrostatic Discharge. They shall be placed as close as possible to the SIM socket. Following references are used: DALC208SC6 from ST Microelectronics, which will be connected, to SIMCLK and SIMDATA. ESDA6V1 from ST Microelectronics for t
