Hardware Design
SIM802_HD_V2.01
SIM802 Hardware Design
Document Title:
Version:
Date:
Status:
Document Control ID:
SIM802 Hardware Design
2.01
2010-01-12
SIM802_HD_V2.01
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. Furthermore, system validation of this product designed
by SIMCom within a larger electronic system remains the responsibility of the customer or the
customer’s system integrator. All specifications supplied herein are subject to change.
Copyright
This document contains proprietary technical information which is the property of SIMCom
Limited., copying of this document and giving it to others and the using or communication of the
contents thereof, are forbidden without express authority. Offenders are liable to the payment of
damages. All rights reserved in the event of grant of a patent or the registration of a utility model
or design. All specification supplied herein are subject to change without notice at any time.
Copyright © Shanghai SIMCom Wireless Solutions Ltd. 2010
SIM802_HD_V2.01 12.01.2010
2
SIM802 Hardware Design
Contents
Contents ........................................................................................................................................... 3
Version history................................................................................................................................. 8
1 Introduction................................................................................................................................... 9
1.1 Related documents .............................................................................................................. 9
1.2 Terms and abbreviations.................................................................................................... 10
1.3 Safety caution.................................................................................................................... 12
2 Product concept........................................................................................................................... 14
2.1 SIM802 key features at a glance ....................................................................................... 15
2.2 SIM802 functional diagram .............................................................................................. 17
2.3 SIM802 evaluation board.................................................................................................. 18
3 Application interface................................................................................................................... 19
3.1 SIM802 Pin description..................................................................................................... 19
3.2 Operating modes ............................................................................................................... 23
3.3 Power supply ..................................................................................................................... 24
3.3.1 Power supply pins ................................................................................................... 25
3.3.2 Minimizing power losses......................................................................................... 26
3.3.3 Monitoring power supply ........................................................................................ 26
3.4 Power up/down scenarios.................................................................................................. 26
3.4.1 Turn on SIM802 ...................................................................................................... 26
3.4.2 Turn off SIM802 ..................................................................................................... 29
3.5 Charging interface............................................................................................................. 32
3.5.1 Battery pack characteristics..................................................................................... 33
3.5.2 Recommended battery pack .................................................................................... 34
3.5.3 Implemented charging technique............................................................................. 34
3.5.4 Operating modes during charging ........................................................................... 35
3.5.5 Charger requirements .............................................................................................. 36
3.6 Power saving ..................................................................................................................... 36
3.6.1 Minimum functionality mode.................................................................................. 37
3.6.2 GSM Sleep mode (slow clocking mode)................................................................. 37
3.6.3 SRD sleep mode (slow clocking mode) .................................................................. 38
3.6.4 Wake up SIM802 from GSM sleep mode ............................................................... 38
3.7 Summary of state transitions (except sleep mode) ............................................................ 38
3.8 RTC backup....................................................................................................................... 39
3.9 Serial interfaces................................................................................................................. 43
3.9.1 Main serial port and Debug serial port supporting .................................................. 44
3.9.2 GSM part software upgrade and software debug .................................................... 45
3.10 Audio interfaces .............................................................................................................. 47
3.10.1 Speaker interface configuration............................................................................. 48
3.10.2 Microphone interfaces configuration..................................................................... 49
3.10.3 Referenced electronic characteristic...................................................................... 49
SIM802_HD_V2.01 12.01.2010
3
SIM802 Hardware Design
3.11 SIM interface................................................................................................................... 50
3.11.1 SIM card application ............................................................................................. 50
3.11.2 Design considerations for SIM card holder ........................................................... 51
3.11.3 Design considerations for SIM card holder ........................................................... 52
3.12 LCD display interface ..................................................................................................... 54
3.13 General purpose input & output (GPIO) ......................................................................... 55
3.14 ADC ................................................................................................................................ 55
3.15 Behaviors of the Ring line (The main serial interface only) ........................................... 56
3.16 Network status indication LED lamp .............................................................................. 57
3.17 SRD interface.................................................................................................................. 57
3.18 Buzzer ............................................................................................................................. 59
4 Antenna interface........................................................................................................................ 60
4.1 Antenna installation........................................................................................................... 60
4.1.1 Antenna pad............................................................................................................. 60
4.2 Module RF output power .................................................................................................. 61
4.3 Module RF receive sensitivity........................................................................................... 61
4.4 Module operating frequencies........................................................................................... 61
5 Electrical, reliability and radio characteristics ............................................................................ 62
5.1 Absolute maximum ratings................................................................................................ 62
5.2 Operating temperatures ..................................................................................................... 62
5.3 Power supply rating........................................................................................................... 62
5.4 Current consumption......................................................................................................... 63
5.5 Electro-Static discharge..................................................................................................... 64
6 Mechanics ................................................................................................................................... 65
6.1 Mechanical dimensions of SIM802................................................................................... 65
6.2 PIN assignment of SIM802............................................................................................... 69
6.3 The ramp-soak-spike reflow profile of SIM802................................................................ 72
SIM802_HD_V2.01 12.01.2010
4
SIM802 Hardware Design
Table Index
TABLE 1: RELATED DOCUMENTS.................................................................................................... 9
TABLE 2: TERMS AND ABBREVIATIONS ...................................................................................... 10
TABLE 3: SIM802 KEY FEATURES................................................................................................... 15
TABLE 4: CODING SCHEMES AND MAXIMUM NET DATA RATES OVER AIR INTERFACE.16
TABLE 5: PIN DESCRIPTION ............................................................................................................ 19
TABLE 6: OVERVIEW OF OPERATING MODES............................................................................. 23
TABLE 7: AT COMMANDS USED IN ALARM MODE .................................................................... 29
TABLE 8: SPEC OF RECOMMENDED BATTERY PACK................................................................ 34
TABLE 9: OPERATING MODES ........................................................................................................ 35
TABLE 10: AT COMMAND USUALLY USED IN GHOST MODE .................................................. 36
TABLE 11: SUMMARY OF STATE TRANSITIONS.......................................................................... 38
TABLE 12: SPECIFICATION OF XH414H-IV01E ............................................................................. 42
TABLE 13: LOGIC LEVELS OF SERIAL PORTS PINS.................................................................... 43
TABLE 14: AUDIO INTERFACE SIGNAL......................................................................................... 47
TABLE 14: MIC INPUT CHARACTERISTICS .................................................................................. 50
TABLE 15: AUDIO OUTPUT CHARACTERISTICS ......................................................................... 50
TABLE 17: SIGNAL OF SIM INTERFACE ........................................................................................ 51
TABLE 18: PIN DESCRIPTION (AMPHENOL SIM CARD HOLDER) ........................................... 53
TABLE 19: PIN DESCRIPTION (MOLEX SIM CARD HOLDER) ................................................... 53
TABLE 20: PIN DEFINITION OF THE LCD INTERFACE ............................................................... 55
TABLE 21: GPIO OF SIM802 .............................................................................................................. 55
TABLE 22: ADC SPECIFICATION ..................................................................................................... 55
TABLE 23: BEHAVIOURS OF THE RING LINE............................................................................... 56
TABLE 24: WORKING STATE OF NETWORK STATUS INDICATION LED PIN ......................... 57
TABLE 25: PIN DEFINITION OF THE SRD INTERFACE ............................................................... 57
TABLE 26: BUZZER OUTPUT CHARACTERISTICS...................................................................... 59
TABLE 27: SIM802 CONDUCTED RF OUTPUT POWER................................................................ 61
TABLE 28: SIM802 CONDUCTED RF RECEIVE SENSITIVITY .................................................... 61
TABLE 29: SIM802 GSM OPERATING FREQUENCIES.................................................................. 61
TABLE 30: SIM802 SRD OPERATING FREQUENCIES................................................................... 61
TABLE 31: ABSOLUTE MAXIMUM RATING.................................................................................. 62
TABLE 32: SIM802 OPERATING TEMPERATURE.......................................................................... 62
TABLE 33: SIM802 POWER SUPPLY RATING................................................................................. 62
TABLE 34: SIM802 CURRENT CONSUMPTION ............................................................................. 63
TABLE 35: THE ESD ENDURE STATUE MEASURED TABLE ...................................................... 64
TABLE 36: PIN ASSIGNMENT........................................................................................................... 69
SIM802_HD_V2.01 12.01.2010
5
SIM802 Hardware Design
Figure Index
FIGURE 1: SIM802 FUNCTIONAL DIAGRAM ................................................................................ 17
FIGURE 2: TOP VIEW OF SIM802 EVB ............................................................................................ 18
FIGURE 3: VBAT INPUT ................................................................................................................. 24
FIGURE 4: REFERENCE CIRCUIT OF THE SOURCE POWER SUPPLY INPUT.......................... 25
FIGURE 5: VBAT VOLTAGE DROP DURING TRANSMIT BURST ............................................... 25
FIGURE 6: TURN ON SIM802 USING DRIVING CIRCUIT ............................................................ 27
FIGURE 7: TURN ON SIM802 USING BUTTON.............................................................................. 27
FIGURE 8 TIMING OF TURN ON SYSTEM ..................................................................................... 28
FIGURE 9: TIMING OF TURN OFF SYSTEM ............................................................................... 30
FIGURE 10: TIMING OF RESTART SYSTEM .................................................................................. 32
FIGURE 11: BATTERY CHARGER AND PACK................................................................................ 33
FIGURE 12: TYPICAL CONNECTION OF DTR ............................................................................... 37
FIGURE 13: RTC SUPPLY FROM NON-CHARGEABLE BATTERY .............................................. 40
FIGURE 14: RTC SUPPLY FROM RECHARGEABLE BATTERY ................................................... 40
FIGURE 15: RTC SUPPLY FROM CAPACITOR ............................................................................... 40
FIGURE 16: PANASONIC EECEMOE204A CHARGE CHARACTERISTIC .................................. 41
FIGURE 17: MAXELL TC614 CHARGE CHARACTERISTIC......................................................... 41
FIGURE 18: SEIKO TS621 CHARGE CHARACTERISTIC .............................................................. 42
FIGURE 19: CONNECTION OF SERIAL PORTS.............................................................................. 44
FIGURE 20: CONNECTION OF SOFTWARE UPGRADE................................................................ 45
FIGURE 21: CONNECTION OF SOFTWARE DEBUG..................................................................... 46
FIGURE 22: RS LEVEL CONVERTER CIRCUIT.............................................................................. 46
FIGURE 23: SPEAKER INTERFACE CONFIGURATION ................................................................ 48
FIGURE 24: SPEAKER INTERFACE WITH AMPLIFIER CONFIGURATIO.................................. 48
FIGURE 26: EARPHONE INTERFACE CONFIGURATION............................................................. 49
FIGURE 27: SIM INTERFACE REFERENCE CIRCUIT WITH 6 PINS SIM CARD ....................... 52
FIGURE 28: AMPHENOL C707-10M006 512 2 SIM CARD HOLDER ............................................ 53
FIGURE 29: MOLEX 91228 SIM CARD HOLDER ........................................................................... 54
FIGURE 30: SIM802 SERVICES AS RECEIVER............................................................................... 56
FIGURE 31: SIM802 SERVICES AS CALLER................................................................................... 56
FIGURE 32: REFERENCE CIRCUIT FOR NETWORK STATUS LED ............................................ 57
FIGURE 33: I2C APPLICATION OF THE SRD INTERFACE ............................................................ 58
FIGURE 34: SPI APPLICATION OF THE SRD INTERFACE ........................................................... 58
FIGURE 35: REFERENCE CIRCUIT OF BUZZER ........................................................................... 59
FIGURE 36: RF PAD (BOTTOM VIEW) ............................................................................................ 60
FIGURE 37: SIM802 TOP VIEW......................................................................................................... 65
FIGURE 38: SIM802 SIDE VIEW ....................................................................................................... 66
FIGURE 39: SIM802 BOTTOM VIEW ............................................................................................... 66
FIGURE 40: PAD BOTTOM VIEW..................................................................................................... 67
FIGURE 41: FOOTPRINT RECOMMENDATION ............................................................................. 68
FIGURE 42: SIM802 PINS DEFINITION (TOP VIEW) .................................................................. 70
FIGURE 43: BOTTOM VIEW OF SIM802 ......................................................................................... 71
SIM802_HD_V2.01 12.01.2010
6
SIM802 Hardware Design
FIGURE 44: TOP VIEW OF SIM802 ................................................................................................... 71
FIGURE 45: THE RAMP-SOAK-SPIKE REFLOW PROFILE OF SIM802....................................... 72
SIM802_HD_V2.01 12.01.2010
7
SIM802 Hardware Design
Version history
Data Version Description of change Author
2010-01-12 2.01 Origin Jirang Feng
Scope of the document
This document is intended for the following versions of the SIMCom modules
•SIM802-A: GSM/GPRS 900/1800 MHz and 850/1900MHz, SRD RF 433MHz Version
SIM802-B: GSM/GPRS 900/1800 MHz and 850/1900MHz, SRD RF 868MHz Version
SIM802-C: GSM/GPRS 900/1800 MHz and 850/1900MHz, SRD RF 915MHz Version
SIM802_HD_V2.01 12.01.2010
8
SIM802 Hardware Design
1 Introduction
This document describes the hardware interface of the SIMCom SIM802 module that connects to
the specific application and the air interface. As SIM802 can be integrated with a wide range of
applications, all functional components of SIM802 are described in great detail.
This document can help you quickly understand SIM802 interface specifications, electrical and
mechanical details. With the help of this document and other SIM802 application notes and user
guide, you can use SIM802 module to design and set-up mobile applications quickly.
1.1 Related documents
Table 1: Related documents
SN Document name Remark
[1] SIM802_ATC SIM802_ATC
[2] ITU-T Draft new
recommendation V.25ter:
[3] GSM 07.07: Digital cellular telecommunications (Phase 2+); AT
[4] GSM 07.05: Digital cellular telecommunications (Phase 2+); Use of
[5] GSM 11.14: Digital cellular telecommunications system (Phase 2+);
[6] GSM 11.11: Digital cellular telecommunications system (Phase 2+);
[7] GSM 03.38: Digital cellular telecommunications system (Phase 2+);
[8] GSM 11.10 Digital cellular telecommunications system (Phase 2)；
Serial asynchronous automatic dialing and control
command set for GSM Mobile Equipment (ME)
Data Terminal Equipment – Data Circuit terminating
Equipment (DTE – DCE) interface for Short Message
Service (SMS) and Cell Broadcast Service (CBS)
Specification of the SIM Application Toolkit for the
Subscriber Identity Module – Mobile Equipment (SIM –
ME) interface
Specification of the Subscriber Identity Module – Mobile
Equipment (SIM – ME) interface
Alphabets and language-specific information
Mobile Station (MS) conformance specification； Part 1:
Conformance specification
[9] GSM 11.10 Digital cellular telecommunications system (Phase 2)；
Mobile Station (MS) conformance specification； Part 1:
Conformance specification
[10] AN_SerialPort AN_SerialPort
SIM802_HD_V2.01 12.01.2010
9
SIM802 Hardware Design
1.2 Terms and abbreviations
Table 2: Terms and abbreviations
Abbreviation Description
ADC Analog-to-Digital Converter
AMR Adaptive Multi-Rate
ARP Antenna Reference Point
ASIC Application Specific Integrated Circuit
BER Bit Error Rate
BTS Base Transceiver Station
CHAP Challenge Handshake Authentication Protocol
CS Coding Scheme
CSD Circuit Switched Data
CTS Clear to Send
DAC Digital-to-Analog Converter
DRX Discontinuous Reception
DSP Digital Signal Processor
DTE Data Terminal Equipment (typically computer, terminal, printer)
DTR Data Terminal Ready
DTX Discontinuous Transmission
EFR Enhanced Full Rate
EGSM Enhanced GSM
EMC Electromagnetic Compatibility
ESD Electrostatic Discharge
ETS European Telecommunication Standard
FCC Federal Communications Commission (U.S.)
FDMA Frequency Division Multiple Access
FR Full Rate
GMSK Gaussian Minimum Shift Keying
GPRS General Packet Radio Service
GSM Global Standard for Mobile Communications
HR Half Rate
I/O Input/Output
IC Integrated Circuit
IMEI International Mobile Equipment Identity
Inorm Normal Current
Imax Maximum Load Current
SIM802_HD_V2.01 12.01.2010
10
SIM802 Hardware Design
kbps Kilo bits per second
LED Light Emitting Diode
Li-Ion Lithium-Ion
MO Mobile Originated
MS Mobile Station (GSM engine), also referred to as TE
MT Mobile Terminated
PAP Password Authentication Protocol
PBCCH Packet Switched Broadcast Control Channel
PCB Printed Circuit Board
PCS Personal Communication System, also referred to as GSM 1900
PDU Protocol Data Unit
PPP Point-to-point protocol
RF Radio Frequency
RMS Root Mean Square (value)
RTC Real Time Clock
Rx Receive Direction
SIM Subscriber Identification Module
SMS Short Message Service
SRD Short range device
TDMA Time Division Multiple Access
TE Terminal Equipment, also referred to as DTE
TX Transmit Direction
URC Unsolicited Result Code
USSD Unstructured Supplementary Service Data
VSWR Voltage Standing Wave Ratio
Vmax Maximum Voltage Value
Vnorm Normal Voltage Value
Vmin Minimum Voltage Value
VIHmax Maximum Input High Level Voltage Value
VIHmin Minimum Input High Level Voltage Value
VILmax Maximum Input Low Level Voltage Value
VILmin Minimum Input Low Level Voltage Value
VImax Absolute Maximum Input Voltage Value
VImin Absolute Minimum Input Voltage Value
VOHmax Maximum Output High Level Voltage Value
VOHmin Minimum Output High Level Voltage Value
VOLmax Maximum Output Low Level Voltage Value
VOLmin Minimum Output Low Level Voltage Value
SIM802_HD_V2.01 12.01.2010
11
SIM802 Hardware Design
y
Phonebook abbreviations
FD SIM fix dialing phonebook
LD SIM last dialing phonebook (list of numbers most recently dialed)
MC Mobile Equipment list of unanswered MT calls (missed calls)
ME Mobile Equipment phonebook
RC Mobile Equipment list of received calls
SM SIM phonebook
DC ME dialed calls list(+CPBW may not be applicable for this storage)(same as
LD)
LA Last Number All list (LND/LNM/LNR)
ON SIM (or ME) own numbers (MSISDNs) list
SD SIM service dial number
VM SIM voice mailbox
BN SIM barred dialed number
1.3 Safety caution
The following safety precautions must be observed during all phases of the operation. Usage,
service or repair of any cellular terminal or mobile incorporating SIM802 module. Manufactures
of the cellular terminal should send words the following safety information to users and operating
personnel and to incorporate these guidelines into all manuals supplied with the product. If not so,
SIMCom does not take on any liability for customer failure to comply with these precautions.
When in a hospital or other health care facility, observe the restrictions about the
use of mobiles. Switch the cellular terminal or mobile off, medical equipment
may be sensitive to not operate normally for RF energy interference.
Switch off the cellular terminal or mobile before boarding an aircraft. Make sure
it be switched off. The operation of wireless appliances in an aircraft is forbidden
to prevent interference with communication systems. Forget to think much of
these instructions may lead to the flight safety or offender against local legal
action, or both.
Do not operate the cellular terminal or mobile in the presence of flammable gases
or fumes. Switch off the cellular terminal when you are near petrol stations, fuel
depots, chemical plants or where blasting operations are in progress. Operation of
any electrical equipment in potentially explosive atmospheres can constitute a
hazard.
safet
SIM802_HD_V2.01 12.01.2010
12
SIM802 Hardware Design
Your cellular terminal or mobile receives and transmits radio frequency energy
while switched on. RF interference can occur if it is used close to TV sets,
radios, computers or other electric equipment.
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. Road safety comes first! Do not use a hand-held cellular terminal or
GSM cellular terminals or mobiles operate over radio frequency signals and
cellular networks and cannot be guaranteed to connect in all conditions, for
example no mobile fee or a invalid SIM card. While y ou are in this condition
and need emergent help, Please Remember using emergency calls. In order to
make or receive calls, the cellular terminal or mobile must be switched on and
in a service area with adequate cellular signal strength.
Some networks do not allow for emergency call if certain network services or
phone features are in use (e.g. lock functions, fixed dialing etc.). You may have
to deactivate those features before you can make an emergency call.
Also, some networks require that a valid SIM card be properly inserted in the
cellular terminal or mobile.
SIM802_HD_V2.01 12.01.2010
13
SIM802 Hardware Design
2 Product concept
Designed for global market, SIM802 module is a complete Quad-Band GSM/GPRS solution that
is also equipped with SRD RF technology and embedded SIM card IC (optional).The GSM/GPRS
engine works on frequencies GSM/GPRS 900/1800 MHz and 850/1900MHz, SIM802 series
features GPRS multi-slot class 10/Class 8 (the default is class 10) capability and supports the
GPRS coding schemes CS-1, CS-2, CS-3 and CS-4. The SRD RF engine works on
433/868/915MHz, SRD RF supports the multi-channel choice, transparent date transfer without
complex user setting.
The compact design of the SIM802 makes it easy to integrate GSM/GPRS & SRD RF as an
all-in-one solution. You will save significantly both time and cost for the integration of additional
hardware components
With a tiny configuration of 33mm x 33mm x 5.2 mm, SIM802 can meet almost all the space
requirement in your application, such as M2M and mobile data communication system etc.
The hardware package of 60 pins
z 12 GND Pins and 2 VBAT pins
z 1 Pin is programmable as General Purpose I/O .This gives you the flexibility to develop
customized applications.
z Serial port and Debug port can help you easily develop your applications. But they can not
work at the same time.
z Two audio channels include two microphone inputs and two speakers’ outputs. This can be
easily configured by AT command.
z LCD display interface.
z Either SIM card interface or embedded SIM card IC is optional.
z Charge interface. Charge circuit integrated inside the SIM802, it is very suitable for the
battery power application.
z GSM RF and SRD RF antenna interface. Customer’s antenna should be located in the
customer’s mainboard and connect to module’s antenna pad through micro strip line or other
type RF traces which impendence must be 50Ω.
2
C and SPI interfaces for SRD.
z I
The SIM802 is designed with power saving technique, so that the current consumption is as low
as 6mA in SLEEP mode (BS-PA-MFRMS=5, only GSM sleep mode current consumption).
The SIM802 is integrated with the TCP/IP protocol，Extended TCP/IP AT commands are
developed for customers to use the TCP/IP protocol easily, which is useful for those data transfer
applications.
.
SIM802_HD_V2.01 12.01.2010
14
SIM802 Hardware Design
2.1 SIM802 key features at a glance
Table 3: SIM802 key features
Feature Implementation
Power supply Single supply voltage 3.4V – 4.5V
Power saving Typical power consumption in SLEEP mode to 6mA
( BS-PA-MFRMS=5 )
Charging Supports charging control for Li-Ion battery
GSM frequency Bands
z SIM802 quad-band: GSM/GPRS 900/1800 MHz and
850/1900MHz. The SIM802 can search the 4 frequency bands
automatically. The frequency bands also can be set by AT
command.
z Compliant to GSM Phase 2/2+
GSM class Small MS（CLASS:A,B,C,D）
Transmit power z Class 4 (2W) at EGSM900/GSM850
z Class 1 (1W) at DCS1800/PCS1900
GPRS connectivity
z GPRS multi-slot class 8 （optional）
z GPRS multi-slot class 10 ( default)
z GPRS mobile station class B
Temperature range
z Normal operation: -30°C to +80°C
z Restricted operation: -40°C to -30°C and +80°C to +85°C
z Storage temperature: -45°C to +90°C
DATA GPRS:
CSD:
z GPRS data downlink transfer: max. 85.6 kbps
z GPRS data uplink transfer: max. 42.8 kbps
z Coding scheme: CS-1, CS-2, CS-3 and CS-4
z SIM802 supports the protocols PAP (Password Authentication
Protocol) usually used for PPP connections.
z The SIM802 integrates the TCP/IP protocol.
z Support Packet Switched Broadcast Control Channel (PBCCH)
z CSD transmission rates: 2.4, 4.8, 9.6, 14.4 kbps,
non-transparent
z Unstructured Supplementary Services Data (USSD) support
(1)
SMS z MT, MO, CB, Text and PDU mode
z SMS storage: SIM card
FAX Group 3 Class 1
SIM interface Support SIM card: 1.8V ,3V
External antenna Connected via 50 Ohm antenna connector or antenna pad
Audio features Speech codec modes:
z Half Rate (ETS 06.20)
z Full Rate (ETS 06.10)
SIM802_HD_V2.01 12.01.2010
15
SIM802 Hardware Design
z Enhanced Full Rate (ETS 06.50 / 06.60 / 06.80)
z Adaptive multi rate (AMR)
z Echo Cancellation
Serial interface and
Debug interface
z Serial Port: Seven lines on Serial Port Interface
z Serial Port can be used for CSD FAX, GPRS service and
sending AT command of controlling module.
z Debug port: provide two lines on Serial Port Interface /TXD
and /RXD
z Debug port is only used for debugging
Phonebook management Support phonebook types: SM, FD, LD, MC, RC, ON,
ME,BN,VM,LA,DC,SD
SIM Application Toolkit Support SAT class 3, GSM 11.14 Release 99
Real time clock Implemented
Timer function Programmable via AT command
Physical characteristics Size: 33±0.15 x 33±0.15 x 5.15±0.15 mm
Weight: 10g
Firmware upgrade Firmware upgrade over serial interface
SRD frequency Bands SIM802-A :433MHz– 434.79MHz
SIM802-B: 863MHz – 870MHz
SIM802-C: 902MHz – 928MHz
SRD modulation schemes GFSK
SRD frequency interval 100KHz
SRD maximum transmit
18dBm
power
SRD receive sensitivity -118dBm@2400bps
SRD air interface date
2400 – 128000bps
rate
SRD TX current
100mA@18dBm (peak value)
consumption
SRD RX current
29mA
consumption
Table 4: Coding schemes and maximum net data rates over air interface
Coding scheme 1 Timeslot 2 Timeslot 4 Timeslot
CS-1: 9.05kbps 18.1kbps 36.2kbps
CS-2: 13.4kbps 26.8kbps 53.6kbps
CS-3: 15.6kbps 31.2kbps 62.4kbps
CS-4: 21.4kbps 42.8kbps 85.6kbps
SIM802_HD_V2.01 12.01.2010
16
SIM802 Hardware Design
2.2 SIM802 functional diagram
The following figure shows a functional diagram of the SIM802 and illustrates the mainly
functional part:
z The GSM baseband engine
z Flash and SRAM
z The GSM radio frequency part
z The GSM antenna interface
z The SRD radio frequency part
z The SRD RF antenna interface
z The embedded SIM card IC (optional)
z The other external interfaces
MIAN
SERIAL
POWER
INTERFACE
LCD
INTERFACE
SIM
INTERFACE
Flash+SRAM
Baseband
Engine
Module
Embed SIM
Card
DEBUG
SERIAL
INTERFACE
Figure 1: SIM802 functional diagram
GSM Radio
Frequency
SRD Radio
Frequency
AUDIO
INTERFACE
GSM RF
PAD
SRD RF
PAD
SIM802_HD_V2.01 12.01.2010
17
SIM802 Hardware Design
2.3 SIM802 evaluation board
In order to help you on the application of SIM802, SIMCom can supply an Evaluation Board
(EVB) that interfaces the SIM802 directly with appropriate power supply, SIM card holder, the
main serial port and debug serial port, handset port, LCD (optional), antenna and all GPIO of the
SIM802.
Figure 2: Top view of SIM802 EVB
For details please refer to the SIM802-EVB_UGD document.
SIM802_HD_V2.01 12.01.2010
18
SIM802 Hardware Design
3 Application interface
All hardware interfaces are described in detail in following chapters:
z Power supply and charging control (see Chapters 3.3 and 3.5)
z Provide main serial interface and debug serial interface (see chapter3.9)
z Two analog audio interfaces (see chapter 3.10)
z SIM interface (see chapter 3.11)
z LCD interface (see chapter 3.12)
z GPIO interface (see chapter 3.13)
z ADC interface (see chapter 3.14)
z Buzzer interface (see chapter 3.18)
3.1 SIM802 Pin description
Table 5: Pin description
Power supply
Pin Name I/O Description DC characteristics Comment
VBAT Power 2 VBAT pins are dedicated to
connect the supply voltage.
The power supply of SIM802
has to be a single voltage
source of VBAT=
3.4V...4.5V. It must be able to
provide sufficient current in a
transmit burst which
typically rises to 2A.Mostly,
these 2 pins are voltage
input, however ,when use the
charge circuit to charge the
battery ,these pins become
the current output, select one
of these pins as the charge
current output Pin
Vmax= 4.5V
Vmin=3.4V
Vnorm=4.0V
VRTC Power Current input for RTC when
the battery is not supplied for
SIM802_HD_V2.01 12.01.2010
19
Vmax=2.0V
Vmin=1.2V
Do not keep pin
open, it should be
SIM802 Hardware Design
the system.
Current output for backup
battery when the main
Vnorm=1.8V
Iout(max)= 20uA
Iin=5 uA
battery is present and the
backup battery is in low
voltage state.
VCHG I Voltage input for the charge
circuit, as the signal for
detecting the charger
connecting
Vmax=5.25V
Vmin=1.1* VBAT
Vnorm=5.1V
Imax=650mA
GND ground Digital ground
Power on or power off
Pin name I/O Description
PWRKEY I Press the key , the PWRKEY
get a low level voltage for
user to power on or power
C characteristics
VILmax=0.2*VBAT
VIHmin=0.6*VBAT
VImax=VBAT
off the system, the user
should keep pressing the key
for a moment when power on
or power off the system.
Because the system need
margin time assert the
software.
connected to a
battery or a
capacitor.
If unused keep pin
open
omment
Pull up to VBAT
inside.
Audio interfaces
Pin name I/O Description DC characteristics Comment
MIC1P
MIC1N
MIC2P
MIC2N
SPK1P
SPK1N
SPK2P
SPK2N
I Positive and negative voice
band input
I Auxiliary positive and
negative voice band input
O Positive and negative voice
band output
O Auxiliary positive and
negative voice band output
Characteristics refer
to chapter 3.10
If unused keep
pins open
AGND Analog ground Separate ground
connection for
external audio
circuits.
If unused, it
should be
connected to GND
General purpose input/output
SIM802_HD_V2.01 12.01.2010
20
SIM802 Hardware Design
Pin name I/O Description DC characteristics Comment
STATUS O Indicate work status VOLmin=GND
VOLmax=0.2V
VOHmin=
If unused keep
pins open
2.93V-0.2
VOHmax= 2.93V
GPIO I/O General Input Output Port
DISP_DATA I/O Display interface
If unused keep
pins open
DISP _CLK O
DISP _CS O
DISP _D/C O
DISP _RST O
KBR0 I Pull up inside, if
unused keep pin
open
Main serial interface
Pin name I/O Description DC characteristics Comment
RXD I Receive data
DTR I Data terminal Ready
TXD O Transmit data
RTS I Request to send
CTS O Clear to send
RI O Ring indicator
DCD O
VILmin=0V
VILmax=0.3*2.93V
VIHmin=0.7*2.93V
VIHmax=
2.93V+0.3
VOLmin=GND
VOLmax=0.2V
VOHmin=
2.93V-0.2
VOHmax= 2.93V
If only use TXD,
RXD, GND three
pins to
communicate,
RTS Pin connect
to GND directly.
DTR Pin is
pulled up inside.
If unused keep
pins open
Debug serial interface
Pin name I/O Description DC characteristics Comment
DBG_TXD O
DBG_RXD I
Serial interface for debug
only
If unused keep
pins open
SIM interface
Pin Name I/O Description DC characteristics Comment
SIM_VDD O Voltage supply for SIM card The voltage can be
select by software
either 1.8V or 3V
SIM_DATA I/O SIM data output
SIM_CLK O SIM clock
SIM_RST O SIM reset
SIM802_HD_V2.01 12.01.2010
21
VILmin=0V
VILmax=0.3*SIM_
VDD
VIHmin=0.7*SIM_
All signals of SIM
interface are
protected against
ESD with a TVS
SIM802 Hardware Design
VDD
VIHmax=
diode array.
SIM_VDD+0.3
VOLmin=GND
VOLmax=0.2V
VOHmin=
SIM_VDD-0.2
VOHmax=
SIM_VDD
ADC
Pin Name I/O Description DC characteristics Comment
ADC0 I General purpose analog to
digital converter.
TEMP_BAT I Measure the battery
Input voltage value
scope 0V to 2.4V
If unused keep
pins open
temperature
SRD interface
Pin name I/O Description DC characteristics Comment
SDA O/I I2C data , default for GPIO
SCK O I2C clock , default for GPIO
NSS O SPI chip select , default for
GPIO
VOLmin=GND
VOLmax=0.2V
VOHmin= 3.3V -0.2
VOHmax= 3.3V
If unused keep
pins open
SCLK O SPI clock , default for GPIO
MOSI O Master out slave in, default
for GPIO
MISO I Master in slave out, , default
for GPIO
C2D Reserve
NRST Reserve
SIM802_HD_V2.01 12.01.2010
22
SIM802 Hardware Design
3.2 Operating modes
The table below briefly summarizes the various operating modes referred to in the following
chapters.
Table 6: Overview of operating modes
Mode Function
GSM/GPRS
SLEEP
Module will automatically go into SLEEP mode if DTR is set to high
level and there is no on air or audio activity is required and no
hardware interrupt (such as GPIO interrupt or data on serial port).
In this case, the current consumption of module will reduce to the
minimal level.
During sleep mode, the module can still receive paging message and
SMS from the system normally.
GSM IDLE Software is active. Module has been registered to the GSM network,
and the module is ready to send and receive.
GSM TALK
Normal operation
Connection is going on between two subscribers. In this case, the
power consumption depends on network settings such as DTX off/on,
FR/EFR/HR, hopping sequences, antenna.
GPRS
STANDBY
Module is ready for GPRS data transfer, but no data is currently sent
or received. In this case, power consumption depends on network
settings and GPRS configuration (e.g. multi-slot settings).
GPRS DATA There is GPRS data in transfer (PPP or TCP or UDP). In this case,
power consumption is related with network settings (e.g. power
control level), uplink / downlink data rates and GPRS configuration
(e.g. used multi-slot settings).
SRD DATA
There are two statuses: receive or transmit .Transmitting power levels
can be set up to 4 levels. Power consumption is related with
transmitting power levels.
For details please refer to document [1]
POWER DOWN Normal shutdown by sending the “AT+CPOWD” command or using
the PWRKEY. The power management ASIC disconnects the power
supply from the baseband part of the module，and only the power
supply for the RTC is remained. Software is not active. The serial
interfaces are not accessible. Operating voltage (connected to BATT)
remains applied.
Minimum functionality
mode (without remove
power supply)
Use the “AT+CFUN” command can set the module to a minimum
functionality mode without remove the power supply. In this case, the
GSM RF part of the module will not work or the SIM card will not be
accessible, or both RF part and SIM card will be closed all, and the
SIM802_HD_V2.01 12.01.2010
23
SIM802 Hardware Design
serial interfaces is still accessible. The power consumption in this case
is very low.
Alarm mode RTC alert function launches this restricted operation while the module
is in POWER DOWN mode. SIM802 will not be registered to GSM
network and only parts of AT commands can be available.
GHOST Mode
(Charge-only mode)
GHOST mode means off and charging mode. In this mode, the
module can not be registered to GSM network and only limited AT
commands can be accessible, the following way will launch GHOST
mode:
z From POWER DOWN mode: Connect charger to the module’s
VCHG Pin and VBAT Pin while SIM802 is power down.
z From Normal mode: Connect charger to the module’s VCHG Pin
and VBAT Pin, then power down the module by “AT+CPOWD”
z From Normal mode: Connect charger to the module’s VCHG Pin
and VBAT Pin, then press the PWRKEY get a low level voltage
for about 2s.
Charge mode during
normal operation
Start charging while the module is in normal mode including: SLEEP,
IDLE, TALK, GPRS STANDBY and GPRS DATA
3.3 Power supply
The power supply of VBAT voltage range is from 3.4 to 4.5V .The ripple in a transmitting burst
may cause voltage drops when current consumption rise to typical peaks of 2A, So the power
supply must be able to provide sufficient current up to 2A.
For the VBAT input, a local bypass capacitor is recommended. For example, a lower cost choice
may be a 100 µF tantalum capacitor (low ESR) with a small (0.1 µF to 1 µF) ceramic in parallel,
which is illustrated as figure 3. The capacitors should be put as closer as possible to the SIM802
VBAT pins.
Figure 3: VBAT input
The circuit design of the power supply depends strongly from the power source where this power
SIM802_HD_V2.01 12.01.2010
24
SIM802 Hardware Design
is drained. The following figure is the reference design of +5V input source power supply. The
designed output for the power supply is 4V, thus a linear regulator can be used. If there’s a big
difference between the input source and the desired output (VBAT), a switching converter power
supply will be preferable because of its better efficiency especially with the 2A peak current in
burst mode of the module.
The single 3.6V Li-Ion cell battery type can be connected to the power supply of the SIM802
VBAT directly. 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.
Figure 4: 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
capacitor (ESR=0.7Ω) and C
577us
=1µF.
B
4.615ms
IVBAT
=100µF tantalum
A
Burst:2A
VBAT
Max:400mV
Figure 5: VBAT voltage drop during transmit burst
3.3.1 Power supply pins
Two VBAT pins of SIM802 are dedicated to connect the supply voltage. Twelve GND pins and
SIM802_HD_V2.01 12.01.2010
25
SIM802 Hardware Design
one analog GND pins are recommended for grounding. The VCHG Pin serves as a control signal
for charging a Li-Ion battery. VRTC Pin can be used to back up the RTC.
3.3.2 Minimizing power losses
Please pay special attention to the supply power when you are designing your applications. Please
make sure that the input voltage will never drop below 3.4V even in a transmitting burst during
which the current consumption may rise up to 2A. If the power voltage drops below 3.4V, the
module may be switched off. You should also take the resistance from the power supply lines on
the host board or from battery pack into account.
3.3.3 Monitoring power supply
To monitor the supply voltage, you can use the “AT+CBC” command which include three
parameters: charging state, voltage percentage and voltage value (in mV). It returns charge state，
the battery voltage 1-100 percent of capacity and actual value measured at VBAT and GND.
The voltage is continuously measured at intervals depending on the operating mode. The
displayed voltage (in mV) is averaged over the last measuring period before the AT+CBC
command is executed.
For details please refer to document [1]
3.4 Power up/down scenarios
3.4.1 Turn on SIM802
SIM802 can be turned on by various ways, which are described in following chapters:
z Via PWRKEY Pin: starts normal operating mode (see chapter 3.2);
z Via VCHG Pin: starts GHOST modes (see chapter 3.4.1.2);
z Via RTC interrupt: starts ALARM modes (see chapter 3.4.1.4)
Note: The AT command must be set after the SIM802 is power on and Unsolicited Result Code
“RDY” is received from the serial port. However if the SIM802 is set autobauding, the serial
port will receive nothing. The AT commands can be set in 2-3s after the SIM802 is power on.
You can use AT+IPR=x;&W to set a fixed baud rate and save the configuration to non-volatile
flash memory. After the configuration is saved as fixed baud rate, the Code “RDY” should be
received from the serial port all the time that the SIM802 is power on. Please refer to the
chapter AT+IPR in document [1].
SIM802_HD_V2.01 12.01.2010
26
SIM802 Hardware Design
3.4.1.1 Turn on SIM802 using the PWRKEY Pin (Power on)
Turn on the SIM802 by driving the PWRKEY to a low level voltage for a period time. This Pin is
pulled up to VBAT in the module. The simple circuit illustrates as the following figures.
PWRKEY
4.7K
Turn on impulse
47K
Figure 6: Turn on SIM802 using driving circuit
S1
TVS1
Figure 7: Turn on SIM802 using button
The power on scenarios illustrates as following figure.
PWRKEY
SIM802_HD_V2.01 12.01.2010
27
SIM802 Hardware Design
VBAT
Pulldo w n > 2 s
Hiz
V
PWRKEY
(INPUT)
VIL<0.2*VBAT
> 0.6*VBAT
IH
STATUS
（OUTPUT）
Figure 8 Timing of turn on system
When power on procedure completed, SIM802 will send out following result code to indicate the
module is ready to operate, when set as fixed baud rate. STATUS Pin will drive to 2.8V and keep
this level when in work mode. If configured to a fixed baud rate, SIM802 will send the result code
“RDY” to indicate that it is ready to operate. This result code does not appear when autobauding
is active.
3.4.1.2 Turn on the SIM802 using the VCHG signal
As described in chapter 3.4, charger can be connected to SIM802’s VCHG Pin regardless of the
module’s operating mode.
If the charger is connected to the module’s VCHG Pin while SIM802 is in POWER DOWN mode,
SIM802 will go into the GHOST mode (Off and charging). In this mode, the module will not
register to network, and only a few AT commands can work in this mode. For detailed
information please refers to chapter 3.5.
When module is powered on using the VCHG signal, SIM802 sends out result code as following
when fixed baud rate:
RDY
GHOST MODE
In GHOST mode, by driving the PWRKEY to a low level voltage for period time (Please refer to
the power on scenarios in 3.4), SIM802 will power up and go into charge mode (charging in
normal mode), all operation and AT commands can be available. In this case, SIM802 will send
out result code as following:
SIM802_HD_V2.01 12.01.2010
28
SIM802 Hardware Design
From GHOST MODE to NORMAL MODE
3.4.1.3 Turn on SIM802 using the RTC (Alarm mode)
Alarm mode is a power-on approach by using the RTC. The alert function of RTC makes the
SIM802 wakeup while the module power off. In alarm mode, SIM802 will not register to GSM
network and the software protocol stack is closed. Thus the parts of AT commands related with
SIM card and Protocol stack will not be accessible, and the others can be used as well as in
normal mode.
Use the AT+CALARM command to set the alarm time. The RTC remains the alarm time if
SIM802 is power down by “AT+CPOWD=1” or by PWRKEY Pin. Once the alarm time expired
and executed, SIM802 will go into the Alarm mode. In this case, SIM802 will send out an
Unsolicited Result Code (URC) when set as fixed baud rate:
RDY
ALARM MODE
During Alarm mode, use AT+CFUN command to query the status of software protocol stack; it
will return 0 which indicates that the protocol stack is closed. Then after 90s, SIM802 will power
down automatically. However, during Alarm mode, if the software protocol is started by
AT+CFUN=1 command, the process of automatic power down will not be available. In ALARM
mode, driving the PWRKEY to a low level voltage for a period time will cause SIM802 to be
powered down. (Please refer to the power down scenarios).
The table follow briefly summarizes the AT commands that are used usually during alarm mode,
for details of the instructions refer to document [1]:
Table 7: AT commands used in Alarm mode
AT command Use
AT+CALARM Set alarm time
AT+CCLK Set data and time of RTC
AT + CP O W D Power down
AT+CFUN Start or close the protocol stack
3.4.2 Turn off SIM802
Following procedure can be used to turn off the SIM802:
z Normal power down procedure: Turn off SIM802 using the PWRKEY Pin
z Normal power down procedure: Turn off SIM802 using AT command
z Under-voltage and over-voltage automatic shutdown: Take effect if under-voltage or
SIM802_HD_V2.01 12.01.2010
29
SIM802 Hardware Design
over-voltage is detected
z Over-temperature or under-temperature automatic shutdown: Take effect if over-temperature
or under-temperature is detected
3.4.2.1 Turn off SIM802 using the PWRKEY Pin (Power down)
You can turn off the SIM802 by driving the PWRKEY to a low level voltage for a period time.
The power down scenarios illustrate as figure 9.
This procedure lets the module log off from the network and allows the software to enter into a
secure state and saves data before completely disconnecting the power supply.
Before the completion of the switching off procedure the module will send out result code:
POWER DOWN
After this moment, the AT commands can not be executed. Module enters the POWER DOWN
mode, only the RTC is still active. POWER DOWN can also be indicated by STATUS Pin, which
is a low level voltage in this mode.
Logout net about 2000ms to 8000ms
Hiz
PWRKEY
（INPUT）
STATUS
（OUTPUT）
1000ms > Pulldown >500ms
>0.6*VBAT
V
IH
<0.2*VBAT
V
IL
Figure 9: Timing of turn off system
3.4.2.2 Turn off SIM802 using AT command
You can use an AT command “AT+CPOWD=1” to turn off the module. This command will make
the module log off from the network and allow the software to enter into a secure state and save
data before completely disconnecting the power supply.
Before the completion of the switching off procedure the module will send out result code:
NORMAL POWER DOWN
After this moment, any AT commands can not be executed. Module enters into the POWER
DOWN mode, only the RTC is still active. POWER DOWN can also be indicated by STATUS
Pin, which is a low level voltage in this mode.
SIM802_HD_V2.01 12.01.2010
30
SIM802 Hardware Design
Please refer to document [1] for detail about the AT command of “AT+CPOWD”.
3.4.2.3 Over-voltage or under-voltage automatic shutdown
The module will constantly monitor the voltage applied on the VBAT. If the voltage ≤ 3.5V, the
following URC will be presented:
UNDER-VOL TAGE WARNNING
If the voltage ≥ 4.5V, the following URC will be presented:
OVER-VOLTAGE WARNNING
The uncritical voltage range is 3.4V to 4.6V. If the voltage ≥ 4.6V or ≤ 3.4V, the module will
be automatic shutdown soon.
If the voltage ≤ 3.4V, the following URC will be presented:
UNDER-VOLTAGE POWER DOWN
If the voltage ≥ 4.6V, the following URC will be presented:
OVER-VOLTAGE POWER DOWN
After this moment, no further more AT commands can be executed. The module logs off from
network and enters POWER DOWN mode, and only the RTC is still active. POWER DOWN can
also be indicated by STATUS Pin, which is a low level voltage in this mode.
3.4.2.4 Over-temperature or under-temperature automatic shutdown
The module will constantly monitor the temperature of the module, if the temperature ≥ 85℃,
the following URC will be presented:
+CMTE:1
If the temperature ≤ -40℃, the following URC will be presented:
+CMTE:-1
The uncritical temperature range is -45℃ to 90℃. If the temperature ≥ 90℃ or ≤ -45℃, the
module will be automatic shutdown soon.
If the temperature ≥ 90℃, the following URC will be presented:
+CMTE:2
If the temperature ≤ -45℃, the following URC will be presented:
+CMTE:-2
SIM802_HD_V2.01 12.01.2010
31
SIM802 Hardware Design
After this moment, the AT commands can’t be executed. The module logs off from network and
enters POWER DOWN mode, and only the RTC is still active. POWER DOWN can also be
indicated by STATUS Pin, which is a low level voltage in this mode.
To monitor the temperature, you can use the “AT+CMTE” command to read the temperature
when the module is power on.
For details please refer to document [1]
You can restart SIM802 by driving the PWRKEY to a low level voltage for a period time, the
same as turning on SIM802 using the PWRKEY Pin. Before restarting the SIM802, you need
delay at least 500ms from detecting the STATUS low level on. The restarting scenarios illustrates
as the following figure.
PWRKEY
（INPUT）
Turn off
Restart > 500ms
Hiz
Startup
STATUS
（OUTPUT）
VIL<870mv
Figure 10: Timing of restart system
3.5 Charging interface
SIM802 has integrated a charging circuit inside the module for Li-Ion batteries charging control,
which make it very convenient for applications to manage their battery charging. A common
connection is shown in the following figure:
SIM802_HD_V2.01 12.01.2010
32
SIM802 Hardware Design
Figure 11: Battery charger and pack
The function of detecting the temperature of battery should be supported by the software in the
module. It’s a customization function. The R
is a NTC thermistor. We recommend to use
TEMP
NCP15XH103F03RC from MURATA. The impedance of the NTC thermistor is 10Kohm in 25 . ℃
Please refer to the fore figure for the reference circuit.
3.5.1 Battery pack characteristics
SIM802 has optimized the charging algorithm for the Li-Ion battery that meets the characteristics
listed below. To use SIM802’s charging algorithm properly, it is recommended that the battery
pack you integrated into your application is compliant with these specifications. The battery pack
compliant with these specifications is also important for the AT command “AT+CBC” to monitor
the voltage of battery, or the “AT+CBC” may return incorrect battery capacity values.
z The maximum charging voltage of the Li-Ion battery pack is 4.2V and the recommended
capacity is 580mAh. If the Battery packs with a capacity more than 580 mAh, it will cost
more time for charging.
z The pack should have a protection circuit to avoid overcharging, deep discharging and
over-current. This circuit should be insensitive to pulsed current.
z On the SIM802, the build-in circuit of SIM802’s power management chipset monitors the
supply voltage constantly. Once the Under-voltage is detected, the SIM802 will be power
down automatically. Under-voltage thresholds are specific to the battery pack.
z The internal resistance of the battery and the protection circuit should be as low as possible.
It is recommended not to exceed 200mΩ.
z The battery pack must be protected from reverse pole connection.
SIM802_HD_V2.01 12.01.2010
33
SIM802 Hardware Design
3.5.2 Recommended battery pack
Following is the spec of recommended battery pack:
Table 8: Spec of recommended battery pack
Product name & type BYD, Li-Ion, 3.7V, 580mAh
To obtain more information
BYD COMPANY LIMITED
Please contact :
Normal voltage 3.7V
Capacity NORMAL 580mAh
Charge Voltage 4.200±0.049V
Max Charge Current 1.5C
Charge Method CC / CV (Constant Current / Constant Voltage)
Max Discharge Current 1.5C (for continuous discharging mode)
Discharge Cut-off Voltage 2.75V/ cell
Internal resistance Initial≤200mΩ
After 400cycles ≤270mΩ
3.5.3 Implemented charging technique
The SIM802 include the function for battery charging. There are three pins in the connector
related with the battery charging function: VCHG, VBAT and BAT_TEMP pins. The VCHG Pin
is driven by an external voltage, system can use this Pin to detect a charger supply and provide
most charging current through SIM802 module to battery when charging is in fast charge state.
The VBAT give out charging current from SIM802 module to external battery. BAT_TEMP Pin
is for user to measure the battery temperature. Just let this Pin open if battery temperature
measuring is not your concern.
So it is very simple to implement charging technique, you need connect the charger to the VCHG
Pin and connect the battery to the VBAT Pin.
The SIM802 detect charger supply and the battery is present, battery charging will happen. If
there is no charger supply or no battery present the charging will not be enabled.
Normally, there are three main states in whole charging procedure.
z DDLO charge and UVLO charge;
z Fast charge;
z Trickle charge;
DDLO charge and UVLO charge:
DDLO (deep discharge lock out) is the state of battery when its voltage is under 2.4V. And
SIM802_HD_V2.01 12.01.2010
34
SIM802 Hardware Design
UVLO (under voltage lock out) means the battery voltage less than 3.2V and more than 2.4V. The
battery is not suitable for fast charge when its condition is DDLO or UVLO. The SIM802
provides a small constant current to the battery when the battery is between DDLO and UVLO. In
DDLO charge, SIM802 gives out 5mA current to the battery. And in UVLO charge, SIM802
provides about 25mA current to the battery.
DDLO charge terminated when the battery voltage reaches 2.4V. UVLO charge terminated when
the battery voltage is up to 3.2V. Both DDLO and UVLO charge are controlled by the SIM802
hardware only.
Fast charge:
If there is a charger supply and battery present and the battery is not in DDLO and UVLO,
SIM802 will enter fast charge state. Fast charge is controlled by the software. Fast charge delivers
a strong and constant current (about 550mA) through VBAT Pin to the battery until battery
voltage reach 4.2V.
Trickle charge:
After fast charging, the battery voltage is close to the whole battery capacity, trickle charge begins.
In this state, the SIM802 charges the battery under constant voltage.
3.5.4 Operating modes during charging
The battery can be charged during various operating mode. That means that when the GSM
engine is in Normal mode (SLEEP, IDLE, TALK, GPRS IDLE or GPRS DATA mode), charging
can be in progress while SIM802 remains operational (In this case the voltage supply should be
sufficient). Here we name Charging in Normal mode as Charge mode.
If the charger is connected to the module’s VCHG Pin and the battery is connected to the VBAT
Pin while SIM802 is in POWER DOWN mode, SIM802 will go into the GHOST mode (Off and
charging). The following table gives the difference between Charge mode and GHOST mode：
Table 9: operating modes
How to activate mode Features
Connect charger to module’s VCHG Pin
and connect battery to VBAT Pin of
module while SIM802 is in Normal
operating mode, including:
IDLE, TALK mode; SLEEP mode etc;
z GSM remains operational and
registered GSM network while
charging is in progress;
z The serial interfaces are available in
IDLE, TALK mode, the AT command
set can be used fully in this case;
Charge Mode
In SLEEP mode, the serial interfaces are
not available, once the serial port is
connected and there is data in transfer.
Then SIM802 will exit the SLEEP mode.
SIM802_HD_V2.01 12.01.2010
35
SIM802 Hardware Design
Connect charger to module’s VCHG Pin
while SIM802 is in POWER DOWN
mode.
IMPORTANT: Here GHOST mode is
GHOST Mode
OFF and Charging mode, it means that not
z Battery can be charged when GSM
engine is not registered to GSM
network;
z Only a few AT commands is available
as listed below.
all software tasks are running.
Note:
VBAT can not provide much more than 5mA current while SIM802 module is during the
DDLO charge state. In other words it is strongly recommended that VBAT should not be the
main power supply in the application subsystem while SIM802 module is during the DDLO
charge state.
Table 10: AT Command usually used in GHOST mode
AT command Function
AT+CALARM Set alarm time
AT+CCLK Set data and time of RTC
AT + CP O W D Power down
AT+CBC Indicated charge state and voltage
AT+CFUN Start or close the protocol
Set AT command“ AT+CFUN =1”,module
can be transferred from GHOST mode to
Charging in normal mode, In GHOST
mode , the default value is 0
3.5.5 Charger requirements
Following is the requirements of charger for SIM802.
- Simple transformer power plug
- Output voltage: 5.0V-5.25V
- Charging current limitation: 650mA
- A 10V peak voltage is allowed for maximum 1ms when charging current is switched off.
- A 1.6A peak current is allowed for maximum 1ms when charging current is switched on.
3.6 Power saving
There are two methods for the module to enter into low current consumption status.
“AT+CFUN=0” is used to set module into minimum functionality mode and DTR hardware
SIM802_HD_V2.01 12.01.2010
36
SIM802 Hardware Design
interface signal can be used to lead system to be SLEEP mode (or Slow clocking mode).
3.6.1 Minimum functionality mode
Minimum functionality mode reduces the functionality of the module to a minimum and, thus,
minimizes the current consumption to the lowest level. This mode is set with the “AT+CFUN”
command which provides the choice of the functionality levels <fun>=0，1，4
z 0: minimum functionality;
z 1: full functionality (Default);
z 4: disable phone both transmit and receive RF circuits;
If SIM802 has been set to minimum functionality by “AT+CFUN=0”, then the RF function and
SIM card function will be closed. In this case, the serial port is still accessible, but all AT
commands need RF function or SIM card function will not be accessible.
If SIM802 has been set by “AT+CFUN=4”, then RF function will be closed. In this case, the
serial ports is still active, but all AT commands need RF function will not be accessible.
After SIM802 has been set by “AT+CFUN=0” or “AT+CFUN=4”, it can return to full
functionality by “AT+CFUN=1”.
For detailed information about “AT+CFUN”, please refer to document [1].
3.6.2 GSM Sleep mode (slow clocking mode)
The SIM802 can be control module to enter or exit the SLEEP mode through DTR signal. The
DTR pin is pulled up to high level by a 10K resistor inside of SIM802 in order to make sure the
module can enter SLEEP mode.
Figure 12: Typical connection of DTR
SIM802_HD_V2.01 12.01.2010
37
SIM802 Hardware Design
When DTR is in high level, and there is no on air and audio activity is required and no hardware
interrupt (such as GPIO interrupt or data on serial port), SIM802 will enter SLEEP mode
automatically. In this mode, SIM802 can still receive paging or SMS from network.
In SLEEP mode, the serial port is not accessible.
Note: For some special soft versions, it requests to set AT command “AT+CSCLK=1” to enable
the sleep mode; the default value is 0, that can’t make the module enter sleep mode. For more
details please refer to the AT command list.
3.6.3 SRD sleep mode (slow clocking mode)
The SRD sleep mode is reserved.
3.6.4 Wake up SIM802 from GSM sleep mode
When SIM802 GSM part is in sleep mode, the following methods can wake up the module.
z Enable DTR Pin to wake up SIM802
If DTR Pin is pull down to a low level，this signal will wake up SIM802 from power saving
mode. The serial port will be active after DTR changed to low level for about 40mS.
z Receiving a voice or data call from network to wake up SIM802
z Receiving a SMS from network to wake up SIM802
z RTC alarm expired to wake up SIM802
Note: DTR Pin should be held low level during communicating between the module and DTE.
3.7 Summary of state transitions (except sleep mode)
Table 11: Summary of state transitions
Further
mode
Current
mode
Power down
mode
Normal
mode
Power down
Normal mode Ghost mode
mode
Use
PWRKEY
AT + CP O W D
Connect charger
or use
PWRKEY
Pin
(Charge-only
mode)
Connect charger
to VCHG and
connect battery
to VBAT
to VCHG and
connect battery
to VBAT, then
switch off
module by
Charging in normal
mode
No direct transition,
but via “Ghost
mode” or “Normal
mode”
Connect charger to
VCHG Pin of
module and connect
battery to VBAT Pin
of module
Alarm mode
Switch on
from
POWER
DOWN mode
by RTC
Set alarm by
“AT+CALAR
M”, and then
switch off the
module.
When the
SIM802_HD_V2.01 12.01.2010
38
SIM802 Hardware Design
Ghost mode
(Charge-only
Disconnect
charger
mode)
Charging in
normal mode
AT + CP O W D
→ “Ghost
mode”, then
disconnect
charger
Alarm mode Use
PWRKEY
Pin or wait
module
switch off
automatically
No direct
transition, but
via “Charging
in normal”
mode
Disconnect
the charger
Use
AT+CFUN
AT+ CP O WD or
using PWRKEY
Turn on the module
using PWRKEY OR
SET AT Command
“AT+CFUN=1”
Switch off
No direct
module by
AT+ CP O WD or
using PWRKEY
No transition Use AT+CFUN let
module enter Normal
mode, then connect
the charger to VCHG
Pin of module
timer expire,
the module
turn on and
enter Alarm
mode
Set alarm by
“AT+CALAR
M”, when the
timer expire,
module will
enter Alarm
mode
transition
3.8 RTC backup
The RTC (Real Time Clock) power supply of module can be provided by an external battery or a
battery (rechargeable or non-chargeable) through VRTC Pin. There is a 10K resistance which has
been integrated in SIM802 module used for limiting current. You need only a coin-cell battery or
a super-cap to VRTC Pin to backup power supply for RTC.
The following figures show various sample circuits for RTC backup.
SIM802_HD_V2.01 12.01.2010
39
SIM802 Hardware Design
Figure 13: RTC supply from non-chargeable battery
Figure 14: RTC supply from rechargeable battery
z Li-battery backup
Figure 15: RTC supply from capacitor
SIM802_HD_V2.01 12.01.2010
40
SIM802 Hardware Design
Rechargeable Lithium coin cells such as the TC614 from Maxell, or the TS621 from Seiko, are
also small in size, but have higher capacity than the double layer capacitors resulting in longer
backup times.
Typical charge curves for each cell type are shown in following figures. Note that the
rechargeable Lithium type coin cells are generally pre-charged from the vendor.
Figure 16: Panasonic EECEMOE204A Charge Characteristic
Figure 17: Maxell TC614 Charge Characteristic
SIM802_HD_V2.01 12.01.2010
41
SIM802 Hardware Design
Figure 18: Seiko TS621 Charge Characteristic
z Capacitor backup
Some suitable coin cells are the coin-type capacitors available from SEIKO (XH414H-IV01E), or
from SHOEI (PAS414HR-VG1). They have a small physical size (4.8 mm diameter) and give
hours of backup time.
The specification of XH414H-IV01E is shown in following table.
Table 12: Specification of XH414H-IV01E
Parameter Min Type Max Unit
Operation temperature -25 70 °C
Rated operation voltage 3.3 V
Charging voltage 3.3 V
Nominal capacity
0.015 mAh
( discharge capacity,3.3V to 2.0V)
Nominal capacity
0.07 F
( electrostatic capacity,3.3V to 0.0V)
Internal impedance 70 Ω
Nominal dimension (diameter) 4.8 mm
Nominal dimension (height) 1.4 mm
Note:
Gold-capacitance backup
Some suitable coin cells are the electric double layer capacitors available from Seiko (XC621),
or from Panasonic (EECEM0E204A). They have a small physical size (6.8 mm diameter) and a
nominal capacity of 0.2 F to 0.3 F, giving hours of backup time.
SIM802_HD_V2.01 12.01.2010
42
SIM802 Hardware Design
3.9 Serial interfaces
SIM802 provides two unbalanced asynchronous serial ports. One is the main serial port and the
other is the debug serial 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 figure 19 shows).
Autobauding supports bit rates from 1200 bps to 115200bps.
Main serial port
z TXD: Send data to the RXD signal line of the DTE
z RXD: Receive data from the TXD signal line of the DTE
Debug serial port
z DBG_TXD: Send data to the /RXD signal line of the DTE
z DBG_RXD: Receive data from the /TXD signal line of the DTE
NOTE: All pins of both serial ports have 8mA driver, the logic levels are described in following
table
Table 13: Logic levels of serial ports pins
Parameter Min Max Unit
Logic low input 0 0.87V V
Logic high input 2.05V 3.23V V
Logic low output GND 0.2 V
Logic high output 2.73V 2.93V V
SIM802_HD_V2.01 12.01.2010
43
SIM802 Hardware Design
Figure 19: Connection of serial ports
Note: The RTS PIN must be connected to the GND in the customer circuit when only the TXD
and RXD are used in the Serial Port communication.
3.9.1 Main serial port and Debug serial port supporting
Main serial port
z Seven lines on Serial Port Interface
z Contains Data lines TXD and RXD, State lines RTS and CTS, Control lines DTR, DCD and
RING;
z 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. SIM802 supports only basic
mode of multiplexing so far.
z Serial Port supports the communication rate as following:
300, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200 Default as 115200bps.
z Autobauding supports baud rates as following:
4800, 9600, 19200, 38400, 57600 and 115200bps
Debug serial port
z Two lines on Serial Port Interface
z Only contains Data lines /TXD and /RXD
z Debug Port only used for debugging. It cannot be used for CSD call, FAX call. And the
Debug port can not use multiplexing function;
z Debug port supports the communication rate as following:
SIM802_HD_V2.01 12.01.2010
44
SIM802 Hardware Design
9600, 19200, 38400, 57600, 115200bps
Note: You can use software to set a fixed baud rate and save the configuration to non-volatile
flash memory. After the configuration was saved as fixed baud rate, the Unsolicited Result
Codes like "RDY" should be received from the serial port all the time when the SIM802 was
power on.
3.9.2 GSM part software upgrade and software debug
The TXD、RXD、DBG_TXD、DBG_RXD、GND must be connected to the IO connector when
user need to upgrade software and debug software, the TXD、RXD should be used for software
upgrade and the DBG_TXD、 DBG_RXD for software debugging. The PWRKEY Pin is
recommended to connect to the IO connector. The user also can add a switch between the
PWRKEY and the GND. The PWRKEY should be connected to the GND when SIM802 is
upgrading software. Please refer to the following figure.
MODULE
(DCE)
TXD
RXD
GND
PWRKEY
RXD
TXD
GND
PWRKEY
IO ConnectorSerial Port
Figure 20: Connection of software upgrade
Note: The RTS PIN must be connected to the GND in the customer circuit when only the TXD
and RXD used in the Serial Port communication.
SIM802_HD_V2.01 12.01.2010
45
SIM802 Hardware Design
Figure 21: Connection of software debug
The main serial port and the debug serial port don’t support the RS_ level and it only supports the
CMOS level. Please refer to the table 5 for details about the voltage level. You should add the
level converter IC between the DCE and DTE. If you connect it to the computer, please refer to
the following figure.
Figure 22: RS232 level converter circuit
Note
：
For detail information about serial port application, please refer to the document [10]
SIM802_HD_V2.01 12.01.2010
46
SIM802 Hardware Design
3.10 Audio interfaces
Table 14: Audio interface signal
Name Pin Function
(AIN1/AOUT1)
MIC1P 21 Microphone1 input +
MIC1N 20 Microphone1 input -
SPK1P 23 Audio1 output+
SPK1N 24 Audio1 output-
(AIN2/AOUT2)
MIC2P 18 Microphone2 input +
MIC2N 19 Microphone2 input -
SPK2P 26 Audio2 output+
SPK2N 25 Audio2 output-
The module provides two analogy input channels, AIN1 and AIN2, which may be used for both
microphone and line inputs. The AIN1 and AIN2 channels are identical. One of the two channels
is typically used with a microphone built into a handset. The other channel is typically used with
an external microphone or external line input. The module analogy input configuration is
determined by control register settings and established using analogy multiplexers.
For each channels, you can use AT+CMIC to adjust the input gain level of microphone, use
AT+SIDET to set the side-tone level. In addition, you can also use AT+CLVL to adjust the output
gain level of both receiver and speaker at the same time, use AT+CHFA to activate one of the two
audio channels and deactivate the other one. For more details, please refer to document [1].
Note: Use AT command AT+CHFA to select audio channel:
0— AIN1/AOUT1 (normal audio channel), the default value is 0.
1— AIN2/AOUT2(aux_audio channel) .
It is suggested that you adopt one of the following two matching circuits in order to improve
audio performance. The difference audio signals have to be layout according to difference signal
layout rules. As show in following figures (Note: all components package are 0603.) If you want
to adopt an amplifier circuit for audio, we recommend National Company’s LM4890. Of course
you can select it according to your requirement.
SIM802_HD_V2.01 12.01.2010
47
SIM802 Hardware Design
3.10.1 Speaker interface configuration
Close to speaker
GND
Differential layout
10pF
33pF
ESD
ANTI
MODULE
MOUDLE
SPK1P
SPK1N
Figure 23: Speaker interface configuration
Differential layout
Amplifier
Circui
t
10pF
10pF
GND
Close to speaker
10pF
10pF
10pF
33pF
33pF
GND
33pF
33p
F
33pF
ESD
ANTI
ESD
ANTI
ESD
ANTI
GND
Figure 24: Speaker interface with amplifier configuration
SIM802_HD_V2.01 12.01.2010
48
SIM802 Hardware Design
3.10.2 Microphone interfaces configuration
Close to Microphone
GND
GND
Difference layout
10pF
MODULE
MICxP
10pF
MICxN
33pF
33pF
GND
ESD
ANTI
Electret
Microphone
AGND
AGND
10pF
GND
33pF
GND
ESD
ANTI
GND
Figure 25: Microphone interface configuration
Figure 26: Earphone interface configuration
3.10.3 Referenced electronic characteristic
SIM802_HD_V2.01 12.01.2010
49
SIM802 Hardware Design
Table 15: MIC Input Characteristics
Parameter Min Typ Max Unit
Worki n g Voltag e 1.2 1.5 2.0 V
Working Current 300 500 uA
External
1.2 2.2 k Ohms
Microphone
Load Resistance
Table 16: Audio Output Characteristics
Parameter Min Typ Max Unit
Normal
Output(SPK1)
Ended
Differential
load
Resistance
Ref level 0.5477
load
27 32 Ohm Single
Vpp
-12.04
dBm
27 32 Ohm
Resistance
Auxiliary
Output(SPK2)
Ended
Ref level 1.0954
-6.02
load
27 32 Ohm Single
Resistance
Ref level 0.5477
-12.04
Vpp
dBm
Vpp
dBm
Differential
load
27 32 Ohm
Resistance
Ref level 1.0954
-6.02
Vpp
dBm
3.11 SIM interface
3.11.1 SIM card application
You can use AT Command to get information in SIM card. For more information, please refer to
document [1].
The SIM interface supports the functionality of the GSM Phase 1 specification and also supports
the functionality of the new GSM Phase 2+ specification for FAST 64 kbps SIM (intended for use
with a SIM application Tool-kit).
Both 1.8V and 3.0V SIM Cards are supported.
SIM802_HD_V2.01 12.01.2010
50
SIM802 Hardware Design
The SIM interface is powered from an internal regulator in the module having normal voltage 3V.
All pins reset as outputs driving low. Logic levels are as described in table
Table 17: Signal of SIM interface
Signal Pin Description
SIM_VDD 9 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.
SIM_DATA 6 SIM Card data I/O
SIM_CLK 7 SIM Card Clock
SIM_RST 8 SIM Card Reset，it's best to connect PF cap to GND for ESD.
Notes: The SIM802 module default supports SIM card interfaces, but the SIM802 module
supports embedded SIM IC also, if the module has embedded SIM IC, SIM card interfaces keep
pins open.
Following is the reference circuit about SIM interface. We recommend an Electro-Static discharge
device ST (www.st.com
) ESDA6V1W5 or ON SEMI (www.onsemi.com ) SMF05C for “ESD
ANTI”. The 22Ω resistors showed in the following figure should be added in series on the IO line
between the module and the SIM card for protecting the SIM I/O port. The pull up resistor (about
10KΩ) must be added on the SIM_DATA line. Note that the SIM peripheral circuit should be
placed close to the SIM card socket.
3.11.2 Design considerations for SIM card holder
The reference circuit about 6 pins SIM card illustrates as following figure.
SIM802_HD_V2.01 12.01.2010
51
SIM802 Hardware Design
22O
22O
22O
22O
22O
SIM802
MODULE
SIM_VDD
SIM_CLK
SIM_RST
SIM_DATA
22P 22P 22P
Figure 27: SIM interface reference circuit with 6 pins SIM card
3.11.3 Design considerations for SIM card holder
220nF
SIM_VDD
GND
SIM_CLK
SIM_RST
SIM CARD
SIM_DATA
MOLEX-91228
TVS
For 6 pins SIM card, we recommend to use Amphenol C707-10M006 512 2 .You can visit
http://www.amphenol.com
for more information about the holder.
SIM802_HD_V2.01 12.01.2010
52
SIM802 Hardware Design
Figure 28: Amphenol C707-10M006 512 2 SIM card holder
Table 18: Pin description (Amphenol SIM card holder)
Pin Signal Description
C1
SIM_VDD SIM Card Power supply, it can identify automatically the
SIM Card power mode, one is 3.0V±10%, and another is
1.8V±10%. Current is about 10mA.
C2
C3
C4
C5
C6
SIM_RST SIM Card Reset.
SIM_CLK SIM Card Clock.
GND Connect to GND.
VPP Not connect.
SIM_DATA SIM Card data I/O.
Table 19: Pin description (Molex SIM card holder)
Pin Signal Description
C1
SIM_VDD SIM Card Power supply, it can identify automatically
the SIM Card power mode, one is 3.0V±10%, and
another is 1.8V±10%. Current is about 10mA.
C2
C3
SIM802_HD_V2.01 12.01.2010
SIM_RST SIM Card Reset.
SIM_CLK SIM Card Clock.
53
SIM802 Hardware Design
C4
C5
C6
C7
C8
SIM Card Detect 0Ω pulled up to VEXT
GND Connect to GND.
VPP Not connect.
SIM_DATA SIM Card data I/O.
SIM Card Detect 10KΩ pulled down to GND
For 8 pins SIM card holder, we recommend to use Molex 91228.You can visit
http://www.molex.com
for more information about the holder.
Figure 29: Molex 91228 SIM card holder
3.12 LCD display interface
SIM802 provides a serial LCD display interface. These are composite pins that can be used as
GPIO ports or LCD display interface according to your application. When used as LCD interface,
the following table is the pin definition. LCD interface timing should be united with the LCD
device.
SIM802_HD_V2.01 12.01.2010
54
SIM802 Hardware Design
Table 20: PIN definition of the LCD interface
Name Pin Function
DISP_CS 58 Display enable
DISP_CLK 13 Display clock
DISP_DATA 14 Display data output
DISP_D/C 16 Display data or command select
DISP_RST 59 LCD reset
Note: This function is not supported in the default firmware. For more information, please
contact SIMCom.
3.13 General purpose input & output (GPIO)
SIM802 provides a limited number of General Purpose Input/Output signal Pin.
Table 21: GPIO of SIM802
Name Pin I/O Description
GPIO 52 I/O General purpose Input/Output
SIM802 supports two general purpose output signal Pins. These Pins can be configured through
AT command “AT+CGPIO” in users’ application to high voltage level or low voltage level. For
detail of this AT command, please refer to
document [1].
3.14 ADC
SIM802 provide one auxiliary ADC (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+RADC” to read the voltage value added on
ADC Pin. For detail of this AT command, please refer to
Table 22: ADC specification
Min Type Max Units
Voltage range 0 2.4 V
ADC Resolution 16 bits
ADC accuracy1 0.59 mV
document [1].
Sampling rate 3 KHz
SIM802_HD_V2.01 12.01.2010
55
SIM802 Hardware Design
3.15 Behaviors of the Ring line (The main serial interface only)
Table 23: Behaviours of the Ring line
State RI respond
Standby HIGH
Voice calling Change LOW, then:
（1）Change to HIGH when establish calling.
（2）Use AT command ATH, the RI Pin changes to HIGH.
（3）Sender hangs up, change to HIGH.
(4) Change to HIGH when SMS received.
Data calling Change LOW, then：
（1）Change to HIGH when establish calling.
（2）Use AT command ATH, the RI changes to HIGH.
SMS When receive SMS, The RI will change to LOW and hold low level about
120 ms, then change to HIGH.
URC Some URCs triggers 120ms low level on RI. For more details, please refer
to document[10]
If the module is used as caller, signal RI will maintain high. But when it is used as receiver,
following is timing of RI.
HIGH
LOW
RI
Power on Ring
MO or MT
Hang up
Ring
Hang on
(talking)
MO or
MT
Hang up
Ring
Figure 30: SIM802 Services as Receiver
Figure 31: SIM802 Services as caller
SIM802_HD_V2.01 12.01.2010
56
SIM802 Hardware Design
3.16 Network status indication LED lamp
The NETLIGHT Pin can be used to drive a network status indication LED lamp. The working
state of this Pin is listed in table 24:
Table 24: Working state of network status indication LED Pin
State SIM802 function
Off SIM802 is not running
64ms On/ 800ms SIM802 does not find the network
64ms On/3000ms SIM802 find the network
64ms On/ 300ms GPRS communication
The reference circuitry for you, shown as following figure:
Figure 32: Reference circuit for Network status LED
3.17 SRD interface
Table 25: Pin definition of the SRD interface
Name I/O Typical Alternate Description
SCLK I/O GPIO Clock of SPI
MISO I/O GPIO Master in slave out of
SIM802_HD_V2.01 12.01.2010
57
General purpose input
and output
SIM802 Hardware Design
SPI
MOSI I/O GPIO Master out slave in of
SPI
NSS I/O GPIO Slave select input of SPI
SCK I/O GPIO I2C clock
SDA I/O GPIO I2C data
C2D Reserve
NRST Reserve
The reference circuit for I2C shown as following figure:
SIM802
MODULE
GSM
SRD
SDA
SCL
APPLICATION
3.3V
R2
R1
SDA
SCL
Figure 33: I2C application of the SRD interface
2
In the application I
C SDA and I2C SCL lines need to be connected to a positive supply voltage
via a pull-up resistor.
The reference circuit for SPI shown as following figure:
SIM802
MODULE
GSM
MISO
MOSI
SRD
SCLK
NSS
Figure 34: SPI application of the SRD interface
APPLICATION
SPI
Note: This function is not supported in the default firmware. For more information, please
contact SIMCom.
SIM802_HD_V2.01 12.01.2010
58
SIM802 Hardware Design
3.18 Buzzer
The buzzer can be used to drive a buzzer to indicate incoming call. The output volume of buzzer
can be set by “AT+CRSL”. The reference circuit for buzzer shown as following figure:
VBAT
MODULE
4.7K
BUZZER
47K
Figure 35: Reference circuit of Buzzer
Table 26: Buzzer output characteristics
Parameter Min Type Max Unit
Work i ng Volta g e 2.4 2.8 3.3 V
Working Current 2 mA
Load Resistance 1 k Ohms
SIM802_HD_V2.01 12.01.2010
59
SIM802 Hardware Design
4 Antenna interface
z The Pin 45 is the GSM RF antenna pad. The RF interface has an impedance of 50Ω.
z The Pin 33 is the SRD RF antenna pad. The RF interface has an impedance of 50Ω.
4.1 Antenna installation
4.1.1 Antenna pad
SIM802 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 50Ω. To help you to ground the antenna, SIM802 comes
with a grounding plane located close to the antenna pad. The antenna pad of SIM802 is shown as
figure 36:
Figure 36: RF Pad (Bottom view)
NOTE
：
Please do reassure that there isn’t any trace under GSM antenna pad and SRD antenna
pad when you paste SIM802 to your main PCB. You can play traces under the pads only when
there is a ground plane separated from disturbing.
SIM802 material properties:
SIM802 PCB material: FR4
Antenna pad: Gold plated pad
SIM802_HD_V2.01 12.01.2010
60
SIM802 Hardware Design
4.2 Module RF output power
Table 27: SIM802 conducted RF output power
Frequency Max Min
EGSM900 33dBm ±2db 5dBm±5db
GSM850 33dBm ±2db 5dBm±5db
DCS1800 30dBm ±2db 0dBm±5db
PCS1900 30dBm ±2db 0dBm±5db
SRD-RF 18dBm 9dBm
The SRD-RF output power can be programmed from 9dBm to 18dBm in 3dB steps. It can be
easily set through AT command.
4.3 Module RF receive sensitivity
Table 28: SIM802 conducted RF receive sensitivity
Frequency Receive sensitivity
EGSM900 < -106dBm
GSM850 < -106dBm
DCS1800 < -106dBm
PCS1900 < -106dBm
SRD-RF <-118dBm@2400bps
4.4 Module operating frequencies
Table 29: SIM802 GSM operating frequencies
Frequency Receive Transmit
EGSM900 925 ～ 960MHz 880 ～ 915MHz
GSM850 869 ～ 894MHz 824 ～ 849 MHz
DCS1800 1805 ～ 1880MHz 1710 ～ 1785MHz
PCS1900 1930 ～ 1990MHz 1850 ～ 1910MHz
Table 30: SIM802 SRD operating frequencies
Module Receive Frequency Frequency Interval
SIM802-A 433 ～ 434.79MHz
SIM802-B 863 ～ 870MHz
SIM802-C 902 ～ 928MHz
SIM802_HD_V2.01 12.01.2010
61
SIM802 Hardware Design
5 Electrical, reliability and radio characteristics
5.1 Absolute maximum ratings
Absolute maximum rating for power supply and voltage on digital and analog pins of SIM802 are
listed in table31:
Table 31: Absolute maximum rating
Parameter Min Max Unit
Peak current of power supply 0 3.0 A
RMS current of power supply (during one TDMA- frame) 0 0.7 A
Voltage at digit pins -0.3 3.3 V
Voltage at analog pins -0.3 3.0 V
Voltage at digit/analog pins in POWER DOWN mode -0.25 0.25 V
5.2 Operating temperatures
The operating temperature is listed in table32:
Table 32: SIM802 operating temperature
Parameter Min Type Max Unit
Ambient temperature -30 25 80 ℃
Restricted operation* -40 to -30 80 to 85 ℃
Storage temperature -45 90 ℃
* SIM802 does work, but the deviation from the GSM specification may occur, For example, the
frequency error or the phase error will be large
5.3 Power supply rating
Table 33: SIM802 power supply rating
Parameter Description Conditions Min Type Max Unit
Supply voltage Voltage must stay within the min/max
values, including voltage drop, ripple,
and spikes.
3.4 4.0 4.5 V VBAT
Voltage drop
during transmit
burst
SIM802_HD_V2.01 12.01.2010
Normal condition, power control level
for Pout max
62
400 mV
SIM802 Hardware Design
IVBAT
Voltage ripple Normal condition, power control level
for Pout max
@ f<200kHz
@ f>200kHz
Average supply
current
POWER DOWN mode
SLEEP mode ( BS-PA-MFRMS=5 )
IDLE mode
GSM850/EGSM 900
DCS1800/PCS1900
TALK mode
GSM850/EGSM 900
DCS1800/PCS1900
DATA mode GPRS, (3 Rx, 2 TX)
GSM850/EGSM 900
DCS1800/PCS1900
DATA mode GPRS, (4 Rx, 1 TX)
GSM850/EGSM 900
DCS1800/PCS1900
50
2
45
uA
2.5
18.7
18
250
184
436
350
245
180
mV
mA
mA
mA
mA
mA
Peak supply
Power control level for Pout max. 2 3 A
current (during
transmission
slot every
4.6ms)
5.4 Current consumption
The values for current consumption listed refer to following table.
Table 34: SIM802 current consumption
Voice Call
GSM 850/EGSM 900 @power level #5 <350mA,Typical 240mA
@power level #10,Typical 125mA
@power level #19,Typical 90mA
DCS1800/PCS1900 @power level #0 <300mA,Typical 220mA
@power level #10,Typical 115mA
@power level #15,Typical 90mA
GPRS Data
DATA mode, GPRS ( 1 Rx,1 Tx ) CLASS 8
GSM 850/EGSM 900 @power level #5 <350mA,Typical 260mA
@power level #10,Typical 125mA
SIM802_HD_V2.01 12.01.2010
63
SIM802 Hardware Design
@power level #19,Typical 90mA
DCS1800/PCS1900 @power level #0 <300mA,Typical 220mA
@power level #10,Typical 83mA
@power level #15,Typical 76mA
DATA mode, GPRS ( 3 Rx, 2 Tx ) CLASS 10
GSM 850/EGSM 900 @power level #5 <550mA,Typical 420mA
@power level #10,Typical 225mA
@power level #19,Typical 142mA
DCS1800/PCS1900 @power level #0 <450mA,Typical 380mA
@power level #10,Typical 140mA
@power level #15,Typical 127mA
DATA mode, GPRS ( 4 Rx,1 Tx ) CLASS 8
GSM 850/EGSM 900 @power level #5 <350mA,Typical 270mA
@power level #10,Typical 160mA
@power level #19,Typical 120mA
DCS1800/PCS1900 @power level #0 <300mA,Typical 230mA
@power level #10,Typical 120mA
@power level #15,Typical 113mA
Class 10 is default set when the module work at data translation mode, the module can also work
at class 8 set by AT command.
5.5 Electro-Static discharge
The GSM engine is not protected against Electrostatic Discharge (ESD) in general. Therefore, it is
subject to ESD handing precautions that typically apply to ESD sensitive components. Proper
ESD handing and packaging procedures must be applied throughout the processing, handing and
operation of any application using a SIM802 module.
The measured values of SIM802 are shown as the following table:
Table 35: The ESD endure statue measured table
The test condition: temperature 25℃, humidity 45%
Part Contact discharge Air discharge
VBAT,GND ±5KV ±10KV
KBR0-4, DTR, RXD, TXD, RTS,
±4KV ±8KV
DISP_DATA, DISP_CLK
Antenna pad ±5KV ±10KV
Other pad ±3KV ±6KV
SIM802_HD_V2.01 12.01.2010
64
SIM802 Hardware Design
6 Mechanics
This chapter describes the mechanical dimensions of SIM802.
6.1 Mechanical dimensions of SIM802
Following shows the mechanical dimensions of SIM802 (top view, side view and bottom view).
All dimensions are shown in millimeters.
Figure 37: SIM802 top view
SIM802_HD_V2.01 12.01.2010
65
SIM802 Hardware Design
Figure 38: SIM802 side view
Figure 39: SIM802 bottom view
SIM802_HD_V2.01 12.01.2010
66
SIM802 Hardware Design
Figure 40: Pad bottom view
Following shows the footprint recommendation dimensions of SIM802.
SIM802_HD_V2.01 12.01.2010
67
SIM802 Hardware Design
Figure 41: Footprint recommendation
Notes：
Keep out on the user mainboard below the test point and the keep out area, as these are solder
mask.
For maintain this module, the placement must be keep a distance between the module and other
component about 3 mm, and the height of near components must less than 16mm.
SIM802_HD_V2.01 12.01.2010
68
SIM802 Hardware Design
6.2 PIN assignment of SIM802
Table 36: PIN assignment
Pin No. NAME Pin No. NAME
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
DBG_RXD
DBG_TXD
RXD
TXD
STATUS
SIM_DATA
SIM_CLK
SIM_RST
SIM_VDD
KROW0
RI
PWRKEY
DISP_CLK
DISP_DATA
VRTC
DISP_D/C
GND
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
GND
GND
SRD_RF
GND
GND
SDA
SCL
SCLK
MISO
MOSI
NSS
C2D
NRST
GND
GSM_RF
GND
GND
18
19
20
21
22
23
24
25
26
27
28
29
30
MIC2P
MIC2N
MIC1N
MIC1P
AGND
SPK1P
SPK1N
SPK2N
SPK2P
TEMP_BAT
VCHG
ADC0
GND
48
49
50
51
52
53
54
55
56
57
58
59
60
GND
GND
VBAT
VBAT
GPIO
NETLIGHT
DCD
DTR
RTS
CTS
DISP_CS
DISP_RST
GND
NOTE: If any Pin you would not use in your application design, it is recommended that leave
the relative pad empty in your main board.
SIM802_HD_V2.01 12.01.2010
69
SIM802 Hardware Design
59 58 57 56 55 54 53 52 50 49 48 47 46 4551 4460
DISP_CS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
GND
DEBUG_RXD
DEBUG_TXD
RXD
TXD
STATUS
SIM_DATA
SIM_CLK
SIM_RST
SIM_VDD
KROW0
RI
PWRKEY
DISP_CLK
DISP_DATA
VRTC
DISP_D/C
GND
DISP_RST
CTS
RTS
DTR
DCD
NETLIGHT
GPIO8
VBAT
VBAT
GND
GND
GND
SIM802
GND
GND
GSM_RF
NRST
MOSI
MISO
SCLK
SRD_RF
C2D
NSS
SCL
SDA
GND
GND
GND
43
42
41
40
39
38
37
36
35
34
33
32
MIC2P
MIC2N
MIC1P
AGND
SPK1P
SPK1N
SPK2N
MIC1N
SPK2P
VCHG
TEMP_BAT
ADC0
GND
GND
18 19 20 21 22 23 24 25 26 27 28 29 30 31
Figure 42: SIM802 pins definition (top view)
SIM802_HD_V2.01 12.01.2010
70
SIM802 Hardware Design
Figure 43: Bottom view of SIM802
Figure 44: Top view of SIM802
SIM802_HD_V2.01 12.01.2010
71
SIM802 Hardware Design
6.3 The ramp-soak-spike reflow profile of SIM802
If both sides of the mainboard have SMD parts, the SIM802 module must be soldered last.
Figure 45: The ramp-soak-spike reflow profile of SIM802
SIM802_HD_V2.01 12.01.2010
72
Shanghai SIMCom Wireless Solutions Ltd.
Add: SIM Technology Building, No.633, Jinzhong Road, Changning District，
Shanghai, P. R. China 200335
Tel: +86 21 3252 3300
Fax: +86 21 3252 3020
URL: www.sim.com/wm
Loading...