SimCom SIM900D Hardware Design
  1. Manuals
  2. Brands
  3. SimCom Manuals
  4. Control Unit
  5. SIM900D EVB
  6. Hardware design

SimCom SIM900D Hardware Design

Hide thumbs Also See for SIM900D:
Table of Contents

Advertisement

Quick Links

Download this manual
a
SIM900D_Hardware
Design_V1.04

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the SIM900D and is the answer not in the manual?

Questions and answers

Related Manuals for SimCom SIM900D

Summary of Contents for SimCom SIM900D

  • Page 1 SIM900D_Hardware Design_V1.04...
  • Page 2 Document Control ID: General Notes SIMCom offers this information as a service to its customers, to support application and engineering efforts that use the products designed by SIMCom. The information provided is based upon requirements specifically provided to SIMCom by the customers. SIMCom has not undertaken any independent search for additional relevant information, including any information that may be in the customer’s possession.

  • Page 3: Table Of Contents

    3.7 Power Saving ..............................33 3.7.1 Minimum Functionality Mode ......................33 3.7.2 Sleep Mode I (CSCLK=1).........................33 3.7.3 Wake Up SIM900D from SLEEP Mode (CSCLK=1) ..............34 3.7.4 Sleep Mode II (CSCLK=2) .......................34 3.7.5 Wake Up SIM900D from SLEEP Mode (CSCLK=2) ..............34 3.8 RTC Backup ..............................34 3.9 Serial Interfaces............................36...
  • Page 4 5.3 Power Supply Ratings ..........................54 5.4 Current Consumption ..........................56 5.5 Electro-Static Discharge..........................56 6 Mechanics ................................58 6.1 Mechanical Dimensions of SIM900D......................58 6.2 Top and Bottom View of the SIM900D.......................60 6.3 PIN Assignment of SIM900D ........................60 6.4 The Ramp-Soak-Spike Reflow Profile of SIM900D...................62 SIM900D_Hardware Design_V1.04 2010.10.09...
  • Page 5 TABLE23: PIN DEFINITION OF THE GPIO INTERFACE ..................51 TABLE24: PIN DEFINITION OF THE PWM ........................ 52 TABLE25: SIM900D CONDUCTED RF OUTPUT POWER..................53 TABLE26: SIM900D CONDUCTED RF RECEIVE SENSITIVITY ................53 TABLE27: SIM900D OPERATING FREQUENCIES..................... 53 TABLE28: ABSOLUTE MAXIMUM RATINGS......................54 TABLE29: SIM900D OPERATING TEMPERATURE ....................
  • Page 6 FIGURE36: SIM900D SIDE MECHANICAL DIMENSIONS ..................59 FIGURE37: RECOMMENDED PCB DECAL (UNIT: MM)..................59 FIGURE38: TOP AND BOTTOM VIEW OF THE SIM900D ..................60 FIGURE39: SIM900D PIN OUT DIAGRAM (TOP VIEW) ................... 60 FIGURE40: THE RAMP-SOAK-SPIKE REFLOW PROFILE OF SIM900D..............62 SIM900D_Hardware Design_V1.04...

  • Page 7: Version History

    §3.4.1.1Update the Figure8: Timing of turn on system using PWRKEY Jing.zhou §3.4.2.1Update the Figure9: Timing of turn off system using PWRKEY §4.2Update the Table25: SIM900D conducted RF receive sensitivity 2010-06-24 1.03 §3.8, Modify the VRTC pin connection when backup is not needed.

  • Page 8: Introduction

    This document describes the hardware interface of the SIMCom SIM900D module that connects to the specific application and the air interface. As SIM900D can be integrated into a wide range of applications, all functional components of SIM900D are described in great detail.
  • Page 9 SIM900D Hardware Design Abbreviation Description Analog-to-Digital Converter Adaptive Multi-Rate Antenna Reference Point ASIC Application Specific Integrated Circuit Bit Error Rate Base Transceiver Station CHAP Challenge Handshake Authentication Protocol Coding Scheme Circuit Switched Data Clear to Send Digital-to-Analog Converter Discontinuous Reception...
  • Page 10 SIM900D Hardware Design Abbreviation Description Mobile Terminated Password Authentication Protocol PBCCH Packet Switched Broadcast Control Channel Printed Circuit Board Personal Communication System, also referred to as GSM 1900 Protocol Data Unit Point-to-point protocol Radio Frequency Root Mean Square (value) Real Time Clock...

  • Page 11: Safety Precautions

    If not so, SIMCom does not take any liability for customer failure to comply with these precautions.
  • Page 12 SIM900D Hardware Design Road safety comes first! Do not use a hand-held cellular terminal or mobile when driving a vehicle, unless it is securely mounted in a holder for hands free operation. Before making a call with a hand-held terminal or mobile, park the vehicle.

  • Page 13: Sim900D Overview

    8 (optional) and supports the GPRS coding schemes CS-1, CS-2, CS-3 and CS-4. With a tiny configuration of 33mm x 33mm x 3mm, SIM900D can meet almost all the space requirements in your applications, such as M2M, smart phone, PDA, FWP, and other mobile devices.
  • Page 14 SIM900D Hardware Design Class 1 (1W) at DCS 1800 and PCS 1900 GPRS connectivity GPRS multi-slot class 10 （default） GPRS multi-slot class 8 (option) GPRS mobile station class B Temperature range Normal operation: -30°C to +80°C Restricted operation: -40°C to -30°C and +80 °C to +85°C Storage temperature -45°C to +90°C...

  • Page 15: Sim900D Functional Diagram

    CS-4: 21.4kbps 42.8kbps 85.6kbps 2.2 SIM900D Functional Diagram The following figure shows a functional diagram of the SIM900D and illustrates the mainly functional part: The GSM baseband engine Flash and SRAM The GSM radio frequency part The antenna interface The Other interfaces SIM900D_Hardware Design_V1.04...

  • Page 16: Sim900D Evaluation Board

    Figure1: SIM900D functional diagram 2.3 SIM900D Evaluation Board In order to help users with the application of SIM900D, SIMCom can supply an Evaluation Board (EVB) that interfaces SIM900D directly with appropriate power supply, SIM card holder, RS232 serial port, handset port, earphone port, antenna and all GPIO of the SIM900D.

  • Page 17: Figure2: Top View Of Sim900D Evb

    SIM900D Hardware Design Figure2: Top view of SIM900D EVB For details please refer to the SIM900D-EVB_UGD document. SIM900D_Hardware Design_V1.04 2010.10.09...

  • Page 18: Application Interface

    SIM900D Hardware Design 3 Application Interface SIM900D is equipped with a 48-pin SMT pad that connects to the cellular application platform. Sub-interfaces included in these SMT pads are described in detail in following chapters: Power supply and charging control (please refer to Chapter 3.3 and 3.5) Serial interface and Debug interface (please refer to chapter3.9)
  • Page 19 SIM900D Hardware Design PIN NAME DESCRIPTION DC CHARACTERISTICS PWRKEY Voltage input for PWRKEY. VILmax=1.2V already PWRKEY should be pulled VIHmin=2.6V pulled up low to power on or power off VIHmax=3.3V the system. The user should VILmin= 0V drive the PWRKEY to low...
  • Page 20 SIM900D Hardware Design sim card present detection pin,by “AT+CSDT”, If unused keep open Serial port PIN NAME DESCRIPTION DC CHARACTERISTICS COMMENT Receive data VILmax=0.4V 1. DTR Pin has VIHmin=2.4V been pulled up. Transmit data VILmin= 0V 2. If RXD pin...

  • Page 21: Operating Modes

    SIM900D Hardware Design digital converter. open TEMP_BAT measure battery If unused keep temperature open. Pulse Width Modulation PIN NAME DESCRIPTION DC CHARACTERISTICS COMMENT PWM Output VOHmin= 2.7V If unused keep VOLmax=0.1V open VOHmax= 3V VOLmin= 0V 3.2 Operating Modes The table below briefly summarizes the various operating modes referred in the following chapters.

  • Page 22: Power Supply

    3.3 Power Supply The power supply of SIM900D is from a single voltage source of VBAT= 3.2V...4.8V. In some case, the ripple in a transmitting burst may cause voltage drops when current consumption rises to typical peaks of 2A. So the power supply must be able to provide sufficient current up to 2A.

  • Page 23: Power Supply Pins

    SIM900D Hardware Design But the Ni_Cd or Ni_MH battery types must be used carefully, since their maximum voltage can rise over the absolute maximum voltage for the module and damage it. Figure4: Reference circuit of the source power supply input The following figure is the VBAT voltage ripple wave at the maximum power transmit phase, the test condition is VBAT=4.0V, VBAT maximum output current =2A, C...

  • Page 24: Monitoring Power Supply

    3.4.1.1 Turn on SIM900D Using the PWRKEY Pin (Power on) User can turn on the SIM900D by driving the PWRKEY to a low level voltage for a short time, then release. This pin has pulled up to 3V in the module. The simple circuit illustrates as the following figures.
  • Page 25 Serial Port Undefined Figure9: Timing of turn on system using PWRKEY When power on procedure completes, the SIM900D will send out following result code to indicate the module is ready to operate when set as fixed baud rate. SIM900D_Hardware Design_V1.04...

  • Page 26: Turn Off Sim900D

    3.4.2.1 Turn Off SIM900D Using the PWRKEY Pin (Power down) User can turn off the SIM900D by driving the PWRKEY to a low level voltage for a short time and then release (Please refer to the turn on circuit).

  • Page 27: Figure10: Timing Of Turn Off System Using Pwrkey

    < 0.1V Figure10: Timing of turn off system using PWRKEY 3.4.2.2 Turn Off SIM900D Using AT Command User can use the AT command “AT+CPOWD=1” to turn off the module. This command lets the module log off from the network and allows the module to enter into a secure state and save data before completely disconnecting the power supply.

  • Page 28: Restart Sim900D Using The Pwrkey Pin

    3.4.3 Restart SIM900D Using the PWRKEY Pin User can restart SIM900D by driving the PWRKEY to a low level voltage for a short time and then release, the same as turning on SIM900D using the PWRKEY pin. Before restarting the SIM900D, user need delay at least 800ms from detecting the STATUS low level on.

  • Page 29: Battery Pack Characteristics

    ℃ 3.5.1 Battery pack characteristics SIM900D has optimized the charging algorithm for the Li-Ion battery that meets the characteristics listed below. The maximum charging voltage of the Li-Ion battery pack is 4.2V and the recommended capacity is 1100mAh. The Battery packs with more than 1100 mAh capacity will cost more time for charging.

  • Page 30: Implemented Charging Technique

    1.5V. The battery is not suitable for fast charging when its condition is DDLO or UVLO. The SIM900D provides a small constant current to the battery when the battery is between DDLO and UVLO. In DDLO charging, SIM900D gives out 1mA current to the battery. And in UVLO charging, SIM900D provides about less than 200mA current to the battery.

  • Page 31: Operating Modes During Charging

    Fast charge: If there is a charger supply and battery present and the battery is not in DDLO and UVLO, SIM900D will enter fast charge state. Fast charge is controlled by the software to make the current/voltage regulation. The charging scheme for the Li-Ion battery is constant current (about 550mA) first, followed by constant voltage charging once 4.2V is reached.

  • Page 32: Charger Requirements

    Charge-only mode to Charging in normal mode. In Charge-only mode, the default value is 0. 3.5.5 Charger requirements Following is the requirements of charger for SIM900D. - Simple transformer power plug - Output voltage: 5.0V-6V - Minimum supply current: 750mA - A 10V peak voltage is allowed for maximum 1ms when charging current is switched off.

  • Page 33: Power Saving

    SIM card function will not be accessible. If SIM900D has been set by “AT+CFUN=4”, the RF function will be closed, the serial port is still active. In this case all AT commands correlative with RF function will not be accessible.

  • Page 34: Wake Up Sim900D From Sleep Mode (Csclk=1)

    Enable DTR pin to wake up SIM900D. If DTR pin is pulled down to a low level，this signal will wake up SIM900D from power saving mode. The serial port will be active after DTR changed to low level for about 50ms.

  • Page 35: Figure14: Rtc Supply From Non-Chargeable Battery

    SIM900D Hardware Design Module VRTC Core Non-chargeable Backup Battery Figure14: RTC supply from non-chargeable battery Module VRTC Core Rechargeable Backup Battery Figure15: RTC supply from rechargeable battery Module VRTC Core Large-capacitance Capacitor Figure16: RTC supply from capacitor Li-battery backup Coin-type Rechargeable Capacitor such as XH414H-IV01E form Seiko can be used.

  • Page 36: Serial Interfaces

    DBG_TXD Transmit data SIM900D provides two unbalanced asynchronous serial ports. One is the serial port and the other is the debug port. The GSM module is designed as a DCE (Data Communication Equipment), following the traditional DCE-DTE (Data Terminal Equipment) connection. The module and the client (DTE) are connected through the following signal (as following figure shows).

  • Page 37: Function Of Serial Port & Debug Port Supporting

    Serial port can be used for CSD FAX, GPRS service and send AT command of controlling module. Also serial port can be used for multiplexing function. SIM900D supports only basic mode of multiplexing so far. Serial port supports the communication rates as following:...

  • Page 38: Software Upgrade And Software Debug

    The TXD and RXD also should be connected to the IO connector, if user wants to send AT command or data stream to SIM900D. The PWRKEY pin is recommended to connect to the IO connector. The user also can add a switch between the PWRKEY and the GND.

  • Page 39: Figure19: Connection Of Software Upgrade And Software Debug

    SIM900D Hardware Design MODULE(DCE) DBG_TXD DBG_RXD PWRKEY PWRKEY I/O Connector Serial port Figure19: Connection of software upgrade and software debug The serial port and the debug port do not support the RS_232 level and it only supports the CMOS level. Please refer to the table 12 for details about the voltage level.

  • Page 40: Audio Interfaces

    The difference audio signals have to be layout according to different signal layout rules. As shown in the following figures (Note: all components package are 0603.) If user wants to adopt an amplifier circuit for audio, SIMCom recommends National Company’s LM4890. Of course users can select it according to their own requirement.

  • Page 41: Speaker Interface Configuration

    SIM900D Hardware Design 3.10.1 Speaker Interface Configuration Close to speaker Differential layout MODULE ANTI 10pF 33pF SPK1P 10pF 33pF SPK1N ANTI 10pF 33pF Figure21: Speaker interface configuration Close to speaker MODULE Differential layout Amplifier 10pF 33pF ANTI Circuit SPK2P 10pF...

  • Page 42: Microphone Interfaces Configuration

    SIM900D Hardware Design 3.10.2 Microphone Interfaces Configuration Close to Microphone MODULE Differential layout 10pF 33pF ANTI MIC1P Electret 10pF 33pF Microphone MIC1N 33pF ANTI 10pF Figure23: Microphone interface configuration 3.10.3 Earphone Interface Configuration Close to Socket Close to MODULE Differential...

  • Page 43: Referenced Electronic Characteristics

    SIM900D Hardware Design 3.10.4 Referenced Electronic Characteristics Table14: MIC Input Characteristics Parameter Unit Working Voltage Working Current External Microphone Load Resistance k Ohms Internal biasing DC Characteristics Differential input 15.9 mVrms THD <1% at F=1KHz; voltage pre-amp gain = 20 dB;...

  • Page 44: Sim Card Interface

    SIM Card data I/O SIM_CLK SIM Card Clock SIM_RST SIM Card Reset Following figure is the reference circuit about SIM interface. SIMCom recommends an Electro-Static discharge device ST (www.st.com ) ESDA6V1W5 or ON SEMI (www.onsemi.com ) SMF05C for “ESD ANTI”. The 22Ω...

  • Page 45: Design Considerations For Sim Card Holder

    Figure26: Reference circuit of the 6-pin SIM card holder 3.11.2 Design Considerations for SIM Card Holder For 6-pin SIM card holder, SIMCom recommends to use Amphenol C707 10M006 512 2 .User can visit http://www.amphenol.com for more information about the holder.

  • Page 46: Table17: Pin Description (Amphenol Sim Card Holder)

    SIM Card Reset. SIM_CLK SIM Card Clock. Connect to GND. Not connect. SIM_DATA SIM Card data I/O. For 8 pins SIM card holder, SIMCom recommends users to use Molex 91228.Users can visit http://www.molex.com for more information about the holder. SIM900D_Hardware Design_V1.04 2010.10.09...

  • Page 47: Table18: Pin Description (Molex Sim Card Holder)

    SIM900D Hardware Design Figure28: Molex 91228 SIM card holder Table 18 : Pin description (Molex SIM card holder) Pin Name Signal Description SIM_VDD SIM Card Power supply, it can identify automatically the SIM Card power mode，one is 3.0V±10%, another is 1.8V±10%. Current is about 10mA.

  • Page 48: Lcd Display Interface

    The DISP_RST can select the KBR0 or GPO0, when KBR0 or GPO0 is not used for another function. 3.13 ADC SIM900D provides one auxiliary ADC0 (General purpose analog to digital converter) as voltage input pin, which can be used to detect the values of some external items such as voltage, temperature etc. User can use AT command “AT+CADC”...

  • Page 49: Behaviors Of The Ri

    SIM900D Hardware Design 3.14 Behaviors of the RI Table21: Behaviours of the RI State RI respond Standby HIGH Voice calling Change LOW, then: （1）Change to HIGH when the call is established. （2）Use AT command ATH, the RI pin will be changed to HIGH.

  • Page 50: Network Status Indication

    Table22: Working state of the NETLIGHT State SIM900D function SIM900D is not running 64ms On/ 800ms Off SIM900D does not find the network 64ms On/ 3000ms Off SIM900D find the network 64ms On/ 300ms Off GPRS communication Provide a reference circuit for user, shown as following figure: SIM900D_Hardware Design_V1.04...

  • Page 51: General Purpose Input Output (Gpio)

    3.16 General Purpose Input Output (GPIO) SIM900D provides a limited number of General Purpose Input/Output signal pin. The output and input voltage level of the GPIO can be set by AT command. For more details, please refer to related document [1]...

  • Page 52: Table24: Pin Definition Of The Pwm

    SIM900D Hardware Design ringtones or alert tones. The tone level can be adjusted over a 24 dB range in 4 dB steps, or it can be muted. Table24: Pin definition of the PWM Pin Name Pin Number Pulse-Width Modulator Signal SIM900D_Hardware Design_V1.04...

  • Page 53: Antenna Interface

    SIM900D Hardware Design 4 Antenna Interface SIM900D provides RF antenna interface. And customer’s antenna should be located in the customer’s main board and connect to module’s antenna pad through microstrip line or other type RF trace which impendence must be controlled in 50Ω.

  • Page 54: Electrical, Reliability And Radio Characteristics

    Table29: SIM900D operating temperature Parameter Unit Ambient temperature ℃ Restricted operation* -40 to -30 +80 to+ 85 ℃ Storage temperature ℃ * The SIM900D does work, but deviations from the GSM specification may occur. 5.3 Power Supply Ratings SIM900D_Hardware Design_V1.04 2010.10.09...

  • Page 55: Table30: Sim900D Power Supply Ratings

    SIM900D Hardware Design Table30: SIM900D power supply ratings Parameter Description Conditions Unit VBAT Supply voltage Voltage must stay within the min/max values, including voltage drop, ripple, and spikes. Voltage drop Normal condition, power control level for during transmit Pout max...

  • Page 56: Current Consumption

    SIM900D Hardware Design 5.4 Current Consumption Please refer to the following table for the values of current consumption. Table31: SIM900D current consumption (VBAT=3.8V) Voice Call GSM 850/EGSM 900 @power level #5 <300mA,Typical 250mA @power level #10,Typical 110mA @power level #19,Typical 80mA DCS 1800/PCS 1900 @power level #0 <200mA,Typical 175mA...

  • Page 57: Table32: The Esd Endure Statue Measured Table (Temperature: 25℃, Humidity:45% )

    SIM900D Hardware Design SIM900D module. The measured values of SIM900D are shown as the following table: ℃ Table32: The ESD endure statue measured table (Temperature: 25 , Humidity:45% ) Part Contact discharge Air discharge VBAT ±5KV ±10KV ±5KV ±10KV RXD, TXD ±2KV...

  • Page 58: Mechanics

    6 Mechanics This chapter describes the mechanical dimensions of SIM900D. 6.1 Mechanical Dimensions of SIM900D Following shows the Mechanical dimensions of SIM900D (top view, side view and bottom view). Dimensions shown in millimeters Figure34: SIM900D top mechanical dimensions Figure35: SIM900D bottom mechanical dimensions SIM900D_Hardware Design_V1.04...

  • Page 59: Figure36: Sim900D Side Mechanical Dimensions

    SIM900D Hardware Design Figure36: SIM900D side mechanical dimensions FOOT PRINT RECOMMENDATION: Figure37: Recommended PCB decal (Unit: mm) SIM900D_Hardware Design_V1.04 2010.10.09...

  • Page 60: Top And Bottom View Of The Sim900D

    SIM900D Hardware Design 6.2 Top and Bottom View of the SIM900D Figure38: Top and Bottom view of the SIM900D 6.3 PIN Assignment of SIM900D DBG_RXD DBG_TXD STATUS SIM_DATA SIM_CLK SIM_RST SIM900D SIM_VDD TOP VIEW KBR0 PWRKEY DISP_CLK DISP_DATA VRTC DISP_D/C Figure39: SIM900D pin out diagram (Top View) SIM900D_Hardware Design_V1.04...

  • Page 61: Table33: Pin Assignment

    SIM900D Hardware Design Table33: PIN Assignment Pin NUM NAME Pin NUM NAME DBG_RXD DBG_TXD STATUS SIM_DATA SIM_CLK SIM_RST SIM_VDD KBR0 PWRKEY DISP_CLK DISP_DATA VRTC DISP_D/C MIC2P MIC2N MIC1N MIC1P AGND SPK1P SPK1N SPK2N SPK2P TEMP_BAT VCHG ADC0 VBAT VBAT GPO1...

  • Page 62: The Ramp-Soak-Spike Reflow Profile Of Sim900D

    SIM900D Hardware Design 6.4 The Ramp-Soak-Spike Reflow Profile of SIM900D Figure40: The ramp-soak-spike reflow profile of SIM900D SIM900D_Hardware Design_V1.04 2010.10.09...
  • Page 63 SIM900D Hardware Design Contact us: Shanghai SIMCom Wireless Solutions Ltd Add: SIM Technology Building A, No. 633, Jinzhong Road, Shanghai, P. R. China 200335 Tel: +86 21 3252 3300 Fax: +86 21 3252 3020 URL: www.sim.com SIM900D_Hardware Design_V1.04 2010.10.09...

Table of Contents