simcom SIM340C User Manual v1.04

Hardware Design

SIM340C_HD_V1.04

SIM340C Hardware Design

Document Title:
Version:
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SIM340C Hardware Design

1.04

2009-03-18

Release

SIM340C_HD_V1.04

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. 2009

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Contents

Contents ............................................................................................................................................3

Version history..................................................................................................................................7

1 Introduction....................................................................................................................................8

1.1 Related documents ...............................................................................................................8

1.2 Terms and abbreviations.......................................................................................................9

2 SIM340C overview......................................................................................................................12

2.1 SIM340C key features........................................................................................................13

2.2 SIM340C functional diagram .............................................................................................14

2.3 SIM340C evaluation board ................................................................................................15

3 Application interface....................................................................................................................16

3.1 SIM340C pin description ...................................................................................................17

3.2 Operating modes ................................................................................................................19

3.3 Power supply ......................................................................................................................20

3.3.1 Power supply pins on the board-to-board connector................................................22

3.3.2 Minimizing power losses..........................................................................................22

3.4 Power up and power down scenarios .................................................................................22

3.4.1 Turn on SIM340C.....................................................................................................22

3.4.2 Turn off SIM340C....................................................................................................26

3.4.3 Restart SIM340C by the PWRKEY pin ...................................................................28

3.5 Charging interface..............................................................................................................28

3.5.1 Battery pack characteristics......................................................................................29

3.5.2 Recommended battery pack .....................................................................................30

3.5.3 Implemented charging technique..............................................................................31

3.5.4 Operating modes during charging ............................................................................31

3.5.5 Charger requirements ...............................................................................................33

3.6 Power saving ......................................................................................................................33

3.6.1 Minimum functionality mode...................................................................................33

3.6.2 Sleep mode (slow clocking mode)............................................................................33

3.6.3 Wake up SIM340C from SLEEP mode....................................................................34

3.7 Summary of state transitions (except SLEEP mode) .........................................................34

3.8 RTC backup........................................................................................................................35

3.9 Serial interfaces..................................................................................................................38

3.9.1 Function of serial port supporting ............................................................................40

3.9.2 Software upgrade and software debug......................................................................41

3.10 Audio interfaces ...............................................................................................................43

3.10.1 Speaker interface configuration..............................................................................44

3.10.2 Microphone interfaces configuration......................................................................45

3.10.3 Earphone interface configuration ...........................................................................46

3.10.4 Referenced electronic characteristic.......................................................................46

3.11 Buzzer ..............................................................................................................................47

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3.12 SIM card interface............................................................................................................48

3.12.1 SIM card application ..............................................................................................48

3.12.2 Design considerations for SIM card holder............................................................50

3.13 LCD display interface ......................................................................................................52

3.14 ADC .................................................................................................................................52

3.15 Behaviors of the RI ..........................................................................................................53

3.16 Network status indication.................................................................................................54

3.17 General purpose input & output (GPIO) ..........................................................................55

3.18 Keypad interface ..............................................................................................................55

4 Antenna interface .........................................................................................................................56

4.1 Antenna installation............................................................................................................57

4.1.1 Antenna connector....................................................................................................57

4.1.2 Antenna pad..............................................................................................................57

4.2 Module RF output power ...................................................................................................57

4.3 Module RF receive sensitivity............................................................................................58

4.4 Module operating frequencies............................................................................................58

5 Electrical, reliability and radio characteristics .............................................................................59

5.1 Absolute maximum ratings.................................................................................................59

5.2 Operating temperatures ......................................................................................................59

5.3 Power supply ratings ..........................................................................................................60

5.4 Current consumption..........................................................................................................61

5.5 Electro-static discharge ......................................................................................................62

6 Mechanics ....................................................................................................................................63

6.1 Mechanical dimensions of SIM340C................................................................................. 63

6.2 Mounting SIM340C onto the application platform............................................................64

6.3 Board to Board connector ..................................................................................................64

6.3.1 Mechanical dimensions of the ASTRON 1590060-09T-R.......................................64

6.4 RF adapter cabling .............................................................................................................65

6.5 PIN assignment of SIM340C Board to Board connector...................................................67

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Table Index

TABLE 1: RELATED DOCUMENTS..................................................................................................... 8

TABLE 2: TERMS AND ABBREVIATIONS .........................................................................................9

TABLE 3: SIM340C KEY FEATURES.................................................................................................13

TABLE 4: CODING SCHEMES AND MAXIMUM NET DATA RATES OVER AIR INTERFACE..14

TABLE 5: BOARD-TO-BOARD CONNECTOR PIN DESCRIPTION ...............................................17

TABLE 6: OVERVIEW OF OPERATING MODES..............................................................................19

TABLE 7: AT COMMANDS USED IN ALARM MODE .....................................................................25

TABLE 8: RECOMMENDED BATTERY PROTECT CIRCUIT PARAMETER................................. 30

TABLE 9: SPEC OF RECOMMENDED BATTERY PACK................................................................. 30

TABLE10: OPERATING MODES ........................................................................................................32

TABLE 11: AT COMMAND USUALLY USED IN GHOST MODE ...................................................32

TABLE 12: SUMMARY OF STATE TRANSITIONS...........................................................................34

TABLE 14: LOGIC LEVELS OF THE SERIAL PORT AND DEBUG PORT .....................................39

TABLE 15: PIN DEFINITION OF THE AUDIO INTERFACE............................................................43

TABLE 16: MIC INPUT CHARACTERISTICS................................................................................... 46

TABLE 17: AUDIO OUTPUT CHARACTERISTICS..........................................................................47

TABLE 18: BUZZER OUTPUT CHARACTERISTICS .......................................................................47

TABLE 19:PIN DEFINITION OF THE SIM INTERFACE ..................................................................48

TABLE 20: PIN DESCRIPTION (AMPHENOL SIM CARD HOLDER) ............................................51

TABLE 21: PIN DESCRIPTION (MOLEX SIM CARD HOLDER) ....................................................52

TABLE 22: PIN DEFINITION OF THE LCD INTERFACE ................................................................52

TABLE 23: PIN DEFINITION OF ADC ...............................................................................................53

TABLE 24: ADC SPECIFICATION ......................................................................................................53

TABLE 25: BEHAVIOURS OF THE RI................................................................................................53

TABLE 26: WORKING STATE OF THE NETLIGHT .........................................................................54

TABLE 27: PIN DEFINITION OF THE GPIO .....................................................................................55

TABLE 29: SIM340C CONDUCTED RF OUTPUT POWER .............................................................. 57

TABLE 30: SIM340C CONDUCTED RF RECEIVE SENSITIVITY ..................................................58

TABLE 31: SIM340C OPERATING FREQUENCIES..........................................................................58

TABLE 32: ABSOLUTE MAXIMUM RATINGS.................................................................................59

TABLE 33: SIM340C OPERATING TEMPERATURE ........................................................................59

TABLE 34: SIM340C POWER SUPPLY RATINGS ............................................................................. 60

TABLE 35: SIM340C CURRENT CONSUMPTION............................................................................61

TABLE 36: THE ESD ENDURE STATUE MEASURED TABLE (TEMPERATURE: 25℃,

HUMIDITY:45% ) .........................................................................................................................62

TABLE 37: CONNECTION DIAGRAMS ............................................................................................67

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Figure Index

FIGURE 1: SIM340C FUNCTIONAL DIAGRAM...............................................................................15

FIGURE 2: TOP VIEW OF SIM340C EVB ..........................................................................................16

FIGURE 3:REFERENCE CIRCUIT OF THE VBAT INPUT ...............................................................21

FIGURE 4: REFERENCE CIRCUIT OF THE SOURCE POWER SUPPLY INPUT...........................21

FIGURE 5: VBAT VOLTAGE DROP DURING TRANSMIT BURST ................................................22

FIGURE 6: TURN ON SIM340C USING DRIVING CIRCUIT...........................................................23

FIGURE 7: TURN ON SIM340C USING BUTTON............................................................................ 23

FIGURE8: TIMING OF TURN ON SYSTEM ......................................................................................24

FIGURE 9: TIMING OF TURN OFF SYSTEM ...................................................................................26

FIGURE10: TIMING OF RESTART SYSTEM ....................................................................................28

FIGURE11: BATTERY CHARGER AND PACK..................................................................................29

FIGURE12: RTC SUPPLY FROM NON-CHARGEABLE BATTERY ................................................ 35

FIGURE13: RTC SUPPLY FROM RECHARGEABLE BATTERY..................................................... 36

FIGURE14: RTC SUPPLY FROM CAPACITOR .................................................................................36

FIGURE 15: PANASONIC EECEMOE204A CHARGE CHARACTERISTIC ...................................37

FIGURE 16: MAXELL TC614 CHARGE CHARACTERISTIC.......................................................... 37

FIGURE 17: SEIKO TS621 CHARGE CHARACTERISTIC............................................................... 38

FIGURE 18: CONNECTION OF THE SERIAL INTERFACE.............................................................40

FIGURE 19: CONNECTION OF SOFTWARE UPGRADE.................................................................42

FIGURE 20: CONNECTION OF SOFTWARE DEBUG......................................................................42

FIGURE 21: RS232 LEVEL CONVERTER CIRCUIT ......................................................................... 43

FIGURE 22: SPEAKER INTERFACE CONFIGURATION .................................................................44

FIGURE 23: SPEAKER INTERFACE WITH AMPLIFIER CONFIGURATION ................................45

FIGURE 24: MICROPHONE INTERFACE CONFIGURATION ........................................................45

FIGURE 25: EARPHONE INTERFACE CONFIGURATION..............................................................46

FIGURE 26: REFERENCE CIRCUIT OF BUZZER ............................................................................ 47

FIGURE 27: REFERENCE CIRCUIT OF THE 8 PINS SIM CARD HOLDER...................................49

FIGURE 28: REFERENCE CIRCUIT OF THE 6 PINS SIM CARD HOLDER...................................49

FIGURE 29: AMPHENOL C707 10M006 512 2 SIM CARD HOLDER.............................................. 50

FIGURE 30: MOLEX 91228 SIM CARD HOLDER ............................................................................51

FIGURE 31: SIM340C SERVICES AS RECEIVER .............................................................................54

FIGURE 32: SIM340C SERVICES AS CALLER .................................................................................54

FIGURE 33: REFERENCE CIRCUIT OF THE NETLIGHT................................................................55

FIGURE 34: REFERENCE CIRCUIT OF THE KEYPAD INTERFACE............................................. 56

FIGURE 35: MECHANICAL DIMENSIONS OF SIM340C（UNIT: MM）......................................63

FIGURE 36:RECOMMENED PCB LAYOUT（UNIT: MM） ........................................................... 63

FIGURE 37: ASTRON1590060-09T-R BOARD TO BOARD CONNECTOR.....................................64

FIGURE 38: ASTRON BOARD TO BOARD CONNECTOR PHYSICAL PHOTO ...........................65

FIGURE 39: MM9329-2700B................................................................................................................ 66

FIGURE 40: RF CONNECTOR MXTK................................................................................................66

FIGURE 41: BOTTOM VIEW OF SIM340C........................................................................................67

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Version history

Date Version Description of change Author

2007-01-23 1.01 origin liyongsheng

2007-08-30 1.02 Modify the current of VDD_EXT to 10mA.

Modify the range of autobauding as 4800-115200bps.

Add the function of over-voltage automatic shutdown.

Add the chapter 2.2, the chapter 2.3, the chapter 3.18,

the Add the figure 1, 2, 4, 6, 7, 21, 34 and the table 8,

24.

Modify the figure 9: Timing of turning off system

(pulldown time of the PWRKEY from 1s-2s to 2s-3s),

figure 5, figure 10.

2007-10-26 1.03 Modify the figure 9: Timing of turning off system

(pulldown time of the PWRKEY from 2s-3s to 0.5s-1s)

Add notes about Restricted operation

2008-03-12 1.04 Modify the duration of DTR low level that wakes up the

module from sleep mode.

Modify the behaviours of RI.

Modify RF connector type MM9329-2700B to

MM9329-2700RA1

Add notes that LCD display interface function is option.

Add notes that keypad interface function is option.

Add notes that GPIO function is option.

song

anyong

Lvning

2009-3-18 1.04 Modify Figure 14: delete ghost KROW4 key.

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1 Introduction

This document describes the hardware interface of the SIMCom SIM340C module that connects

to the specific application and the air interface. As SIM340C can be integrated with a wide range

of applications, all functional components of SIM340C are described in great detail.

This document can help you quickly understand SIM340C interface specifications, electrical and

mechanical details. With the help of this document and other SIM340C application notes, user

guide, you can use SIM340C module to design and set-up mobile applications quickly.

1.1 Related documents

Table 1: Related documents

SN Document name Remark

[1] SIM300C_ATC SIM300C_ATC

[2] ITU-T Draft new

Serial asynchronous automatic dialing and control

recommendation

V.25ter:

[3] GSM 07.07: Digital cellular telecommunications (Phase 2+); AT command

set for GSM Mobile Equipment (ME)

[4] GSM 07.05: Digital cellular telecommunications (Phase 2+); Use of Data

Terminal Equipment – Data Circuit terminating Equipment

(DTE – DCE) interface for Short Message Service (SMS) and

Cell Broadcast Service (CBS)

[5] GSM 07.10: Support GSM 07.10 multiplexing protocol

[6] GSM 11.14: Digital cellular telecommunications system (Phase 2+);

Specification of the SIM Application Toolkit for the Subscriber

Identity Module – Mobile Equipment (SIM – ME) interface

[7] GSM 11.11: Digital cellular telecommunications system (Phase 2+);

Specification of the Subscriber Identity Module – Mobile

Equipment (SIM – ME) interface

[8] GSM 03.38: Digital cellular telecommunications system (Phase 2+);

Alphabets and language-specific information

[9] GSM 11.10 Digital cellular telecommunications system (Phase 2) ；

Mobile Station (MS) conformance specification； Part 1:

Conformance specification

[10]

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1.2 Terms and abbreviations

Table 2: Terms and abbreviations

Abbreviation Description

ADC Analog-to-Digital Converter
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

kbps Kilo bits per second

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LED Light Emitting Diode

Abbreviation Description

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

TDMA Time Division Multiple Access

TE Terminal Equipment, also referred to as DTE

TX Transmit Direction

UART Universal Asynchronous Receiver & Transmitter

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

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Phonebook abbreviations
Abbreviation Description

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)

ON SIM (or ME) own numbers (MSISDNs) list

RC Mobile Equipment list of received calls

SM SIM phonebook

M2M Machine to Machine

NC Not connect

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2 SIM340C overview

Designed for global market, SIM340C is a Quad-band GSM/GPRS engine that works on

frequencies of GSM 850 MHz, EGSM 900 MHz, DCS 1800 MHz and PCS 1900 MHz.SIM340C
features GPRS multi-slot class 10/ class8（optional） capability and support the GPRS coding

schemes CS-1, CS-2, CS-3 and CS-4.

With a tiny configuration of 50mm x 33mm x 6.2mm, SIM340C can meet almost all the space

requirement in your industrial application, such as M2M, and mobile data communication system

etc. With the charge circuit integrated inside the SIM340C, it is very suitable for the battery power

application.

The physical interface to the mobile application is a 60 pins Board to Board connector, which

provides all hardware interfaces between the module and customers’ boards except the RF antenna

interface.

z The keypad and LCD display interface will give you the flexibility to develop customized

applications.

z Serial port and Debug port can help you easily develop your applications.

z Two audio channels include two microphones inputs and two speakers’ outputs. This can be

easily configured by AT command.

z Charge interface

The SIM340C provides RF antenna interface with alternatives: antenna connector and antenna pad.

The antenna connector is MURATA MM9329-2700. And customer’s antenna can be soldered to

the antenna pad.

The SIM340C is designed with power saving technique; so that the current consumption is as low

as 2.5mA in SLEEP mode.

The SIM340C 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 very useful for those data

transfer applications.

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2.1 SIM340C key features

Table 3: SIM340C key features

Feature Implementation

Power supply Single supply voltage 3.4V – 4.5V

Power saving Typical power consumption in SLEEP mode to 2.5mA

(BS-PA-MFRMS =5 )

Frequency Bands

z SIM340C Quad-band: GSM 850, EGSM 900, DCS 1800, PCS

1900. The SIM340C 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

Transmitting power z Class 4 (2W) at EGSM900

z Class 1 (1W) at DCS1800 and PCS 1900

GPRS connectivity

z GPRS multi-slot class 10 (default)
z GPRS multi-slot class 8 （option）
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 SIM340C supports the protocols PAP (Password Authentication

Protocol) usually used for PPP connections.

z The SIM340C 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)
z Enhanced Full Rate (ETS 06.50 / 06.60 / 06.80)

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z Echo suppression

Serial port and Debug

port

z Serial port: seven lines on serial interface
z Serial port can be used for CSD FAX, GPRS service and send

AT command to control module.

z Serial port can use multiplexing function
z Autobauding supports baud rate from 4800 bps to 115200bps.
z Debug port: two lines on serial interface /TXD and /RXD
z Debug port only used for debugging

Phonebook management Support phonebook types: SM, FD, LD, RC, ON, MC.

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: 50±0.15 x 33±0.15 x7.7±0.3mm (including application

connector)

50±0.15 x 33±0.15 x 6.2±0.3mm (excluding application

connector)

Weight: 13.8g

Firmware upgrade Firmware upgrade by serial port

(1) The SIM340C does works, but deviations from the GSM specification may occur, For example,

both the frequency error and the phase error will be large.

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

2.2 SIM340C functional diagram

The following figure shows a functional diagram of the SIM340C and illustrates the mainly

functional part:

z The GSM baseband engine
z Flash and SRAM
z The GSM radio frequency part
z The antenna interface
z The board-to-board interface

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Antenna
connector

Flash+

SRAM

SIM340C

Radio

Frequency

Baseband

Engine

POWER

SIM

KEYPADS

LCD

UART

GPIO

ADC

Board-to-board Connector

AUDIO

Figure 2: SIM340C functional diagram

2.3 SIM340C evaluation board

In order to help you on the application of SIM340C application, SIMCom can supply an

Evaluation Board (EVB) that interfaces the SIM340C directly with appropriate power supply, SIM

card holder, RS232 serial port, handset port, earphone port, antenna and all GPIO of the

SIM340C.

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SIM340C Hardware Design

Figure 3: Top view of SIM340C EVB

For details please refer to the SIM340C-EVB_UGD document.

3 Application interface

SIM 300C is equipped with a 60-pin 1.27mm pitch Board to Board connector that connects to the

cellular application platform. Sub-interfaces included in this Board to Board connector are

described in detail in following chapters:

z Power supply (please refer to Chapter 3.3
z Serial interfaces (please refer to Chapter 3.9
z Two analog audio interfaces (please refer to Chapter 3.10
z SIM card interface (please refer to Chapter 3.12

Electrical and mechanical characteristics of the Board to Board connector are specified in Chapter

6. There we also include order information for mating connectors.

)

)

)

)

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3.1 SIM340C pin description

Table 5: Board-to-board connector pin description
Power Supply

PIN NAME I/O DESCRIPTION DC CHARACTERISTICS

VBAT 5 VBAT pins of the Board to Board

connector are dedicated to connect

the supply voltage. The power supply

of SIM340C has to be a single

voltage source of VBAT= 3.4V...4.5V.

It must be able to provide sufficient

current in a transmitting burst which

typically rises to 2A. may be about

0.1ms up to 3A in some times , these

5 pins are voltage input

VRTC I/O Current input for RTC when the

battery is not supplied for the system.

Current output for backup battery

when the main battery is present and

the backup battery is in low voltage

state.

VDD_EXT O Supply 2.93V voltage for external

circuit. By measuring this pin, user

can judge whether the system is

power on or off. When the voltage is

low, the system is power off.

Otherwise, the system is power on.

Vmax= 4.5V

Vmin=3.4V

Vnorm=4.0V

Vmax=2.0V

Vmin=1.2V

Vnorm=1.8V

Iout(max)= 20uA

Iin=5 uA

Vmax=3.0V

Vmin=2.75V

Vnorm=2.93V

Imax=10mA

VCHG I Voltage input for the charge circuit;

making the system detect the charger.

Vmax=5.25V

Vmin=1.1 * VBAT

Vnorm=5.1V

GND Digital ground

Power on or power off

PIN NAME I/O DESCRIPTION DC CHARACTERISTICS

PWRKEY I Voltage input for PWRKEY.

PWRKEY should be pulled low to

power on or power off the system.

VILmax=0.2*VBAT

VIHmin=0.6*VBAT

VImax=VBAT

The user should keep pressing the

key for a moment when power on or

power off the system because the

system need margin time in order to

assert the software.

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Audio interfaces

PIN NAME I/O DESCRIPTION DC CHARACTERISTICS

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

Audio DC Characteristics

refer to chapter 3.10.4

BUZZER O Buzzer output

AGND Analog ground

General purpose input/output

PIN NAME I/O DESCRIPTION DC CHARACTERISTICS

KBC0~KBC4 O

KBR0~KBR4 I

DISP_DATA I/O

DISP_CLK O

DISP_CS O

DISP_D/C O

DISP_RST O

Keypad interface

LCD display interface

VILmin=0V

VILmax=0.3 *VDD_EXT

VIHmin=0.7*VDD_EXT

VIHmax= VDD_EXT+0.3

VOLmin=GND

VOLmax=0.2V

VOHmin= VDD_EXT-0.2

VOHmax= VDD_EXT

NETLIGHT O Network status indication

STATUS O Indicate work status

GPIO0 I/O

Normal input/output port

GPIO1 I/O

Serial port

PIN NAME I/O DESCRIPTION DC CHARACTERISTICS

DTR I Data terminal ready

RXD I Receive data

TXD O Transmit data

RTS I Request to send

VILmin=0V

VILmax=0.3*VDD_EXT

VIHmin=0.7*VDD_EXT

VIHmax= VDD_EXT+0.3

VOLmin=GND

CTS O Clear to send

RI O Ring indicator

DCD O Data carrier detection

VOLmax=0.2V

VOHmin= VDD_EXT-0.2

VOHmax= VDD_EXT

Debug port

DBG_TXD O

Serial interface for debugging only

DBG_RXD I

SIM interface

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PIN NAME I/O DESCRIPTION DC CHARACTERISTICS

SIM_VDD O Voltage supply for SIM card The voltage can be select

by software automatically

either 1.8V or 3V

SIM_DATA I/O SIM data output

SIM_CLK O SIM clock

SIM_PRESENCE I SIM card detection

SIM_RST O SIM reset

VILmin=0V

VILmax=0.3*SIM_VDD

VIHmin=0.7*SIM_VDD

VIHmax= SIM_VDD+0.3

VOLmin=GND

VOLmax=0.2V

VOHmin= SIM_VDD-0.2

VOHmax= SIM_VDD

AUXADC

PIN NAME I/O DESCRIPTION DC CHARACTERISTICS

ADC0 I General purpose analog to digital

converter.

Input voltage range: 0V to

2.4V

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

Normal operation GSM/GPRS

SLEEP

Module will automatically go into SLEEP mode if DTR is set

to high level and there is no on air 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 registered to the GSM network,

and the module is ready to send and receive.

GSM TALK 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

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.

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19

SIM340C Hardware Design

power control level), uplink / downlink data rates and GPRS

configuration (e.g. used multi-slot settings).

POWER DOWN Normal shutdown by sending the “AT+CPOWD=1” command or using the

PWRKEY. The power management ASIC disconnects the power supply from

the base band part of the module, and only the power supply for the RTC is

remained. Software is not active. The serial port is not accessible. Operating

voltage (connected to VBAT) 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 RF part of the module

will not work or the SIM card is not accessible, or both RF part and SIM card be

closed all, and the serial port 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. SIM340C 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 SIM340C 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＝1”

Charge mode

during normal

Start charging while the module is in normal mode including: SLEEP, IDLE,

TALK, GPRS STANDBY and GPRS DATA)

operation

3.3 Power supply

The power supply of SIM340C is from a single voltage source of VBAT= 3.4V...4.5V. 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.

For the VBAT input, a local bypass capacitor is recommended. A capacitor (about 100µF, low

ESR) is recommended. Multi-layer ceramic chip (MLCC) capacitors can provide the best

combination of low ESR and small size but may not be cost effective. A lower cost choice may be

a 100µF tantalum capacitor (low ESR) with a small (0.1µF to 1µF) ceramic in parallel, which is

illustrated as following figure. The capacitors should put as close as possible to the SIM340C

VBAT pins. The following figure is the recommended circuit.

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20

SIM340C Hardware Design

Figure 3: Reference circuit of the VBAT input

The circuit design of the power supply depends strongly from the power source (DC input) where

this power is drained. The following figure is the reference design of DC input source power

supply. The designed VBAT 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 SIM340C

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

SIM340C_HD_V1.04 18.03.2009

=1µF.

B

21

=100µF tantalum

A

SIM340C Hardware Design

577us

4.615ms

IVBAT

Burst:2A

VBAT

Max:400mV

Figure5: VBAT voltage drop during transmit burst

3.3.1 Power supply pins on the board-to-board connector

Five VBAT pins of the board-to-board connector are dedicated to connect the supply voltage; Five

GND pins are recommended for grounding. 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. The PCB traces from the VBAT pins of connector to the power

source must be wide enough to ensure no voltage drops occur in the transmitting burst mode.

3.3.3 Monitoring power supply

To monitor the supply voltage, you can use the “AT+CBC” command which include three

parameters: charging status, percent of battery capacity and voltage value (in mV). It returns

charge state, the percent of battery 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.

3.4 Power up and power down scenarios

3.4.1 Turn on SIM340C

SIM340C can be turned on by various ways, which are described in following chapters:

z Via PWRKEY pin: starts normal operating mode (please refer to chapter 3.4.1.1);
z Via RTC interrupt: starts ALARM modes (please refer to chapter 3.4.1.2)

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SIM340C Hardware Design

Note: The AT command must be set after the SIM340C is power on and Unsolicited Result Code
“RDY” is received from the serial port. However, if the SIM340C was set autobauding, the
serial port will received nothing, the AT command can be set after 2-3s from the SIM340C is
power on. You can use AT+IPR=x;&W to set a fix baud rate and save the configuration to
non-volatile flash memory. After the configuration was saved as fix baud rate, the Code “RDY”
should be received from the serial port all the time that the SIM340C was power on. Please
refer to the chapter AT+IPR in document [1].

3.4.1.1 Turn on SIM340C using the PWRKEY pin (Power on)

You can turn on the SIM340C by driving the PWRKEY to a low level voltage for some time and

then released. The simple circuit illustrates as the following figures.

PWRKEY

4.7K

Turn on impulse

Figure 6: Turn on SIM340C using driving circuit

Figure 7: Turn on SIM340C using button

47K

S1

PWRKEY

TVS1

The power on scenario illustrates as following figure.

SIM340C_HD_V1.04 18.03.2009

23

SIM340C Hardware Design

VBAT

Pulldown > 2s

Hiz

> 0.6*VBAT

PWRKEY

(INPUT)

VIL<0.2*VBAT

V

IH

STATUS

（OUTPUT）

Figure8: Timing of turn on system

When power on procedure complete, SIM340C will send out following result code to indicate the

module is ready to operate, and STATUS pin will drive to 2.8V and keep this level when in work

mode. If the SIM340C is configured to a fix baud rate, it will send out an Unsolicited Result Code

(URC):

RDY

This result code does not appear when autobauding is active.

3.4.1.2 Turn on SIM340C using the RTC (Alarm mode)

Alarm mode is a power-on approach by using the RTC. The alert function of RTC makes the

SIM340C wake up while it is power off. In alarm mode, SIM340C 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

SIM340C is power down by “AT+CPOWD=1” or by PWRKEY pin. Once the alarm time expires

and executed, SIM340C will go into the Alarm mode. In this case, if the SIM340C is configured

to a fixed baud rate, it will send out an Unsolicited Result Code (URC):

RDY

ALARMMODE

This result code does not appear when autobauding is active.

During alarm mode, using AT+CFUN command to query the status of software protocol stack; it

SIM340C_HD_V1.04 18.03.2009

24

SIM340C Hardware Design

will return 0 which indicates that the protocol stack is closed. Then after 90s, SIM340C 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 will cause SIM340C to be

powered down (Please refer to the power down scenario).

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

3.4.1.3 Turn on the SIM340C using the VCHG signal

As described in chapter 3.5, charger can be connected to the SIM340C’s VCHG pin regardless of

the module’s operating mode.

If the charger is connected to the module’s VCHG pin while the SIM340C is in POWER DOWN

mode, it 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 3.5.4.

When the SIM340C is powered on using the VCHG signal and configured to a fixed baud rate, it

will send out a result code as following:

RDY
GHOST MODE
+CFUN: 0

This result code does not appear when autobauding is active.

In GHOST mode, by driving the PWRKEY to a low level voltage for period time (Please refer to

the power on scenario in 3.4.1.1), the SIM340C will power up and go into charge mode (charging

in normal mode), all operation and AT commands can be available. In this case, if the SIM340C is

configured to a fixed baud rate, it will send out result code as following:

From GHOST MODE to NORMAL MODE

This result code does not appear when autobauding is active.

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SIM340C Hardware Design

3.4.2 Turn off SIM340C

Following procedure can be used to turn off the SIM340C:

z Normal power down procedure: Turn off SIM340C using the PWRKEY pin
z Normal power down procedure: Turn off SIM340C using AT command
z Over-voltage or under-voltage automatic shutdown: Take effect if over-voltage or

under-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 SIM340C using the PWRKEY pin (Power down)

You can turn off the SIM340C by driving the PWRKEY to a low level voltage for some time.

Please refer to the turn on circuit. The power down scenario illustrates as following figure.

This procedure lets the module log off from the network and allow the software to enter into a

secure state and save data before completely disconnect the power supply.

Before the completion of the switching off procedure the module will send out result code:

NORMAL POWER DOWN

After this moment, the AT commands can’t be executed. The module enters the POWER DOWN

mode, only the RTC is still active. POWER DOWN can also be indicated by VDD_EXT pin,

which is a low level voltage in this mode.

Logout net about 2s to 8s

PWRKEY

（INPUT）

1s>Pulldown >0.5s

V

VIL<0.2*VBAT

>0.6*VBAT

IH

STATUS

（OUTPUT）

Figure 8: Timing of turn off system

3.4.2.2 Turn off SIM340C using AT command

You can use an AT command “AT+CPOWD=1” to turn off the module. This command will let

the module to log off from the network and allow the module to enter into a secure state and save

data before completely disconnecting the power supply.

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SIM340C Hardware Design

Before the completion of the switching off procedure the module will send out result code:

NORMAL POWER DOWN

After this moment, the AT commands can’t be executed. The module enters the POWER DOWN

mode, only the RTC is still active. POWER DOWN can also be indicated by VDD_EXT pin,

which is a low level voltage in this mode.

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-VOLTAGE 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 VDD_EXT 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

SIM340C_HD_V1.04 18.03.2009

27

SIM340C Hardware Design

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

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 VDD_EXT 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]

3.4.3 Restart SIM340C by the PWRKEY pin

You can restart SIM340C by driving the PWRKEY to a low level voltage for some time, the same

as turn on SIM340C using the PWRKEY pin. Before restarting the SIM340C, you need delay at

least 0.5s from detecting the STATUS low level on. The restarting scenario illustrates as the

following figure.

PWRKEY

（INPUT）

STATUS

（OUTPUT）

Turn off

Delay > 0.5s

H

VIL<0.3*VDD_EX T

Restart

Pull down the PWR KEY

to turn on the module

Figure10: Timing of restart system

3.5 Charging interface

The SIM340C has integrated a charging circuit inside the module for Li-Ion batteries charging

SIM340C_HD_V1.04 18.03.2009

28

SIM340C Hardware Design

control, which make it very convenient for applications to manage their battery charging.

A common connection is shown in the following figure:

Figure11: Battery charger and pack

The TEMP_BAT function should be supported by the software in the module. It’s a customization

function. The R

is a NTC thermistor. We recommend using NCP15XH103F03RC from

TEMP

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

The SIM340C has optimized the charging algorithm for the Li-Ion battery that meets the

characteristics listed below. To use the SIM340C’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 capacity is

recommended to 580mAh. Battery packs with a The capacity of battery packs down to

580mAh or more than 580mAh are allowed, too.

z The battery pack should have a protection circuit to avoid overcharging, over discharging and

over-current. This circuit should be insensitive to pulsed current.

z The build-in circuit of the SIM340C’s power management chipset monitors the supply

voltage constantly. Once the Under-voltage is detected, the SIM340C will 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.

SIM340C_HD_V1.04 18.03.2009

29

SIM340C Hardware Design

It is recommended that the battery internal resistanc should not to exceed 70mΩ and the

internal resistance include battery and protection circuit of battery pack should not exceed

130mΩ.

z The battery pack must be protected from reverse pole connection.
z The Li-Lon/Polymer battery charge protect parameter is required as following table

Table 8: recommended battery protect circuit parameter

Item Min. Typ. Max. Unit

Over-charge protect threshold. 4.25 4.3 4.35 V

Released Voltage from Over-charge 4.1 4.2 V

Over-discharge protect threshold 2.2 2.35 V

Released Voltage from Over-discharge 2.35 2.4 2.45 V

3.5.2 Recommended battery pack

Following is the spec of recommended battery pack:

Table 9: Spec of recommended battery pack

Product name & type SCUD Li-Ion, 3.7V, 800mAh

To obtain more information,

SCUD (FU JIAN) Electronic CO..LTD

Please contact :

Normal voltage 3.7V

Capacity Minimum 800mAh

Charge Voltage 4.200~4.23V

Max Charge Current 1.2C

Max Discharge Current 2C

Charge Method CC / CV (Constant Current / Constant Voltage)

Internal resistance ≤130mΩ

Over-charge protect threshold.(V) 4.28 ± 0.025

Released Voltage from Over-charge(V) 4.08 ± 0.05

Over-discharge protect threshold(V) 2.3± 0.1

Released Voltage from Over-discharge(V) 2.3± 0.1

SIM340C_HD_V1.04 18.03.2009

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SIM340C Hardware Design

3.5.3 Implemented charging technique

The SIM340C includes the function for battery charging. There are two pins in the connector

related with the battery charging function: VCHG and VBAT 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 the SIM340C module to battery when charging is in fast charge state. The VBAT

gives out charging current from the SIM340C module to external battery.

So it is very simple to implement charging technique, you need only connect the charger to the

VCHG pin and connect the battery to the VBAT pin.

The SIM340C 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 under 2.4V. And 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 SIM340C provides a

small constant current to the battery when the battery is between DDLO and UVLO. In DDLO

charge, the SIM340C gives out 5mA current to the battery. And in UVLO charge, The SIM340C

provide about 30mA 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 SIM340C

hardware only.

Fast charge:

If there is a charger supply and battery present and the battery is not in DDLO and UVLO, the

SIM340C will enter fast charge state. Fast charge controlled by the software. Fast charge delivers

a strong and constant current (about 450mA) through VBAT pin to the battery until battery

voltage reach 4.2V.

Trickle charge:

After fast charging, the battery voltage is approach the whole battery capacity voltage, trick charge

begins .in this state, the SIM340C charge the battery under constant voltage.

3.5.4 Operating modes during charging

The battery can be charged during various operating mode. That means when the module is in

Normal mode (SLEEP, IDLE, TALK, GPRS IDLE or GPRS DATA mode), charging can be in

SIM340C_HD_V1.04 18.03.2009

31

SIM340C Hardware Design

progress while the SIM340C 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 the SIM340C is in POWER DOWN mode, the SIM340C will go into the GHOST mode

(Off and charging). The following table gives the difference between Charge mode and GHOST

mode:

Table10: operating modes

Charge Mode

How to activate mode Features

Connect charger to module’s VCHG

pin and connect battery to VBAT pin

of module while the SIM340C 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 interface is available in

IDLE, TALK mode, the AT command

set can be used fully in this case;

In SLEEP mode, the serial interface is not

available, once the serial port is connected

and there is data in transfer. Then the

SIM340C will exit the SLEEP mode.

Connect charger to module’s VCHG

pin while the SIM340C is in POWER

DOWN mode.

GHOST Mode

z Battery can be charged when GSM

engine is not registered to GSM

network;

z Only a few AT commands are

available as listed below.

Note: VBAT can not provide much more than 5mA current while SIM340C 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 SIM340C module is during the DDLO
charge state.

Table 9: 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

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SIM340C Hardware Design

3.5.5 Charger requirements

Following is the requirements of charger for the SIM340C.

- 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”

is used to set module into minimum functionality mode and DTR hardware interface signal can be

used to lead system to be in 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 SIM340C 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 correlative with RF function or SIM card function will not be accessible.

If SIM340C 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.

After SIM340C 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 Sleep mode (slow clocking mode)

We can control SIM340C module to enter or exit the SLEEP mode in customer applications

through DTR signal. Please note that the DTR pin is float inside SIM340C, so this pin must be in

SIM340C_HD_V1.04 18.03.2009

33

SIM340C Hardware Design

HIGH level to make the module enter SLEEP mode.

When DTR is in high level and there is no on air and hardware interrupt (such as GPIO interrupt

or data on serial port), SIM340C will enter SLEEP mode automatically. In this mode, SIM340C

can still receive paging or SMS from network but the serial port is not accessible.

Note: For SIM340C, 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 our AT command list.

3.6.3 Wake up SIM340C from SLEEP mode

When SIM340C is in SLEEP mode, the following method can wake up the module.

z Enable DTR pin to wake up SIM340C.

If DTR Pin is pulled down to a low level, this signal will wake up SIM340C from power

saving mode. The serial port will be active after DTR change to low level for about 40ms.

z Receiving a voice or data call from network to wake up SIM340C.
z Receiving a SMS from network to wake up SIM340C.
z RTC alarm expired to wake up SIM340C.

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 10: Summary of state transitions

Further
mode

POWER
DOWN

Normal
mode

Alarm mode Ghost mode

Current

mode

POWER

DOWN

Use

PWRKEY

Switch on from

POWER DOWN

mode by RTC

Normal

mode

AT+CPOWD

or use

PWRKEY pin

Set alarm by

“AT+CALARM”

, and then switch

off the module.

When the timer

expire, the module

turn on and enter

Alarm mode

(Charge-only
mode)

Connect charger

to VCHG and

connect battery to

VBAT

Connect charger

to VCHG and

connect battery to

VBAT, then

switch off module

by AT+CPOWD

or using

PWRKEY

Charging in
normal

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 Use Use No transition Use AT+CFUN let

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SIM340C Hardware Design

mode PWRKEY pin

or wait

module

switch off

automatically

Ghost

mode

Disconnect

charger

(Charge-o

nly mode)

Charging

in normal

AT+CPOWD

→ “Ghost

mode” , then

disconnect

charger

3.8 RTC backup

AT+CFUN module enter

Normal mode, then

connect the charger

to VCHG pin of

module

No direct

transition, but

via “Charging

in normal”

mode

Set alarm by

“AT+CALARM”

, when the timer

expire, module

will enter Alarm

Turn on the module

using PWRKEY OR

SET AT Command

“AT+CFUN=1”

mode

Disconnect

the charger

No direct

transition

Switch off module

by AT+CPOWD

or using

PWRKEY

The RTC (Real Time Clock) power supply of module can be provided by an external capacitor or

a battery (rechargeable or non-chargeable) through the VRTC on the board to board connector.

There is a 10K resistance has been integrated in SIM340C module used for limiting current. You

need only a coin-cell battery or a super-cap to VRTC to backup power supply for RTC.

Note: The VRTC couldn’t be designed to a NC pin in your circuit. You should connect the
VRTC pin to a battery or a capacitor.

The following figures show various sample circuits for RTC backup.

module

VRTC

Non-chargeable
Backup Battery

10K

RTC

Core

Figure12: RTC supply from non-chargeable battery

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SIM340C Hardware Design

module

Rechargeable

Backup Battery

Figure13: RTC supply from rechargeable battery

Large-capacitance

Capacitor

VRTC

VRTC

10K

10K

RTC

Core

module

RTC

Core

Figure14: RTC supply from capacitor

z Li-battery backup

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 generally come pre-charged from the vendor.

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SIM340C Hardware Design

Figure 9: Panasonic EECEMOE204A Charge Characteristic

Figure 10: Maxell TC614 Charge Characteristic

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SIM340C Hardware Design

Figure 11: Seiko TS621 Charge Characteristic

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 0.2F to 0.3F, giving hours of backup time.

3.9 Serial interfaces

Table 13: Pin definition of the serial interfaces

Name Pin Function

DCD 37 Data carrier detection

DTR 39 Data terminal ready

RXD 41 Receive data

Serial port

TXD 43 Transmit data

RTS 45 Request to send

CTS 47 Clear to send

RI 49 Ring indicator

Debug port

DBG_RXD 48 Receive data

DBG_TXD 50 Transmit data

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SIM340C provides two unbalanced asynchronous serial ports. One is the serial port and another 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). Autobauding

supports baud rate from 4800 bps to 115200bps.

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 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

The logic levels are described in following table

Table 11: Logic levels of the serial port and debug port

Parameter Min Max Unit

VIL 0 0.3*VDD_EXT V

VIH 0.7 *VDD_EXT VDD_EXT +0.3 V

VOL GND 0.2 V

VOH VDD_EXT -0.2 VDD_EXT V

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SIM340C Hardware Design

MODULE (DCE)

TXD

RXD

RTS

CTS

DTR

DCD

RI

Debug port

DBG_TXD

DBG_RXD

Figure 12: Connection of the serial interface

CUSTOMER (DTE)

Serial port1Serial port

TXD

RXD

RTS

CTS

DTR

DCD

RI

Serial port2

/TXD
/RXD

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 Function of serial port supporting

Serial port

z Seven lines on serial interface
z Contains data lines TXD and RXD, State lines RTS and CTS, Control lines DTR, DCD and

RI.

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.

z Serial port supports the baud rates 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.

Autobauding allows the GSM engine to automatically detect the baud rate configured in the host

application. The serial port of the GSM engine supports autobauding for the following baud rates:

4800, 9600, 19200, 38400, 57600, 115200bps. Factory setting is autobauding enabled. This gives

you the flexibility to put the GSM engine into operation no matter what baud rate your host

application is configured to. To take advantage of autobauding mode specific attention should be

paid to the following requirements:





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SIM340C Hardware Design

Synchronization between DTE and DCE

When DCE powers on with the autobauding enabled, it is recommended to wait 2 to 3 seconds

before sending the first AT character. After receiving the “OK” response, DTE and DCE are

correctly synchronized.

Restrictions on autobauding operation

z The serial port has to be operated at 8 data bits, no parity and 1 stop bit (factory setting).
z The Unsolicited Result Codes like "RDY", "+CFUN: 1" and "+CPIN: READY” are not

indicated when you start up the ME while autobauding is enabled. This is due to the fact that

the new baud rate is not detected unless DTE and DCE are correctly synchronized as

described above.

Note: 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 Unsolicited
Result Codes like "RDY" should be received from the serial port all the time that the SIM340C
was power on.

Debug port

z Two lines on serial interface
z Only contains data lines DBG_TXD and DBG_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; it doesn’t support autobauding function.

z Debug port supports the baud rates as following:

9600, 19200, 38400, 57600, 115200bps

3.9.2 Software upgrade and software debug

The TXD、RXD、DBG_TXD、DBG_RXD and 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, 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 SIM340C is upgrading software.

Please refer to the following figure.

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SIM340C Hardware Design

MODULE(DCE)

CUSTOMER(DTE)

Serial port
TXD

RXD

GND

TXD

RXD

GND

PWRKEY

Figure 13: Connection of software upgrade

Note: The RTS PIN must be connected to the GND in the customer circuit when only TXD and
RXD are used in the Serial Port communication.

MODULE(DCE)

CUSTOMER(DTE)

Debug port
DBG_TXD

DBG_RXD

GND

Figure 20: Connection of software debug

The serial port and the debug port doesn’t support the RS_232 level, it only supports the CMOS

level. Please refer to the table 14 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.

TXD

RXD

GND

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SIM340C Hardware Design

Figure 14: RS232 level converter circuit

Note

：

For detail information about serial port application, please refer to document [10]

3.10 Audio interfaces

Table 12: PIN definition of the Audio interface

Name Pin Function

(AIN1/AOUT1)

(AIN2/AOUT2)

The module provides two analogy input channels, AIN1 and AIN2, which may be used for both

microphone and line inputs. The electret microphone is recommended when the interface used for

microphone. 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 multiplexes.

MIC1P 54 Microphone1 input +

MIC1N 56 Microphone1 input -

SPK1P 53 Audio1 output+

SPK1N 55 Audio1 output-

MIC2P 58 Microphone2 input +

MIC2N 60 Microphone2 input -

SPK2P 57 Audio2 output+

SPK2N 59 Audio2 output-

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SIM340C Hardware Design

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.

3.10.1 Speaker interface configuration

Figure 22: Speaker interface configuration

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SIM340C Hardware Design

Figure 23: Speaker interface with amplifier configuration

3.10.2 Microphone interfaces configuration

Close to Microphone

GND

GND

Difference layout

10pF

MODULE

MICxP

MICxN

AGND

AGND

10pF

10pF

GND

GND

33pF

33pF

33pF

GND

ESD

ANTI

Electret

Microphone

ESD

ANTI

GND

Figure 24: Microphone interface configuration

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SIM340C Hardware Design

3.10.3 Earphone interface configuration

Close to Socket

Close to MODULE

MIC2N
MIC2P

MODULE

SPK2P

1uF

AGND

33pF 33pF

AGND

3.10.4 Referenced electronic characteristic

10R

GNDGND

Figure 25: Earphone interface configuration

Difference

layout

33pF

33pF 10pF

ESD

ANTI

GND

GND

GND

GND

68R

33pF

GND

AGND

GND

3

4
2
1

Amphenol

9001-8905-050

ESD

ANTI

Table 13: MIC input characteristics

Parameter Min Typ Max Unit

Work i ng Vol tag e 1.2 1.5 2.0 V

Working Current 200 500 uA

External

Microphone

1.2 2.2 k Ohms

Load Resistance

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SIM340C Hardware Design

Table 14: Audio output characteristics

Parameter Min Typ Max Unit

load Resistance 27 32 Ohm

Single Ended

Normal

Output(SPK1)

Differential

Nominal Output

Level(PGA=0dB)

0.5477

-12.04

Vpp

dBm

load Resistance 27 32 ohm

Nominal Output

Level(PGA=0dB)

1.0954

-6.02

Vpp

dBm

load Resistance 27 32 Ohm

Single Ended

Auxiliary

Output(SPK2)

Differential

Nominal Output

Level(PGA=0dB)

0.5477

-12.04

Vpp

dBm

load Resistance 27 32 ohm

Nominal Output

Level(PGA=0dB)

1.0954

-6.02

Vpp

dBm

3.11 Buzzer

The BUZZER on the Board to Board connector 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 26: Reference circuit of BUZZER

Table 15: Buzzer output characteristics

Parameter Min Typ Max Unit

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SIM340C Hardware Design

Work i ng Vol tag e 2.4 2.8 3.3 V

Working Current 2 mA

Load Resistance 1 k Ohms

3.12 SIM card interface

3.12.1 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.

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 16:PIN definition of the SIM interface

Name Pin Description

SIM_VDD 25 SIM Card Power output automatic output on SIM

mode, one is 3.0V±10%, and another is

1.8V±10%. Current is about 10mA.

SIM_DATA 29 SIM Card data I/O

SIM_CLK 31 SIM Card Clock

SIM_RST 27 SIM Card Reset

SIM_PRESENCE 33 SIM Card Presence

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”. Note that the SIM peripheral circuit should be closed to the SIM card socket.

The SIM_PRESENCE pin is used for detecting the SIM card removal. You can use the AT

command “AT+CSDT” to configure this function. For detail of this AT command, please refer to

document [1]:

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SIM340C Hardware Design

You can select the 8 pins SIM card holder. The reference circuit about 8 pins SIM card holder

illustrates as the following figure.

Figure 27: Reference circuit of the 8 pins SIM card holder

If you don’t use the SIM card detection function, you can let the SIM_PRESENCE pin connect to

the GND. The reference circuit about 6 pins SIM card holder illustrate as the following figure.

Figure 28: Reference circuit of the 6 pins SIM card holder



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SIM340C Hardware Design

3.12.2 Design considerations for SIM card holder

For 6 pins SIM card holder, we recommend to use Amphenol C707 10M006 512 2 .You can visit

http://www.amphenol.com

for more information about the holder.

Figure 15: Amphenol C707 10M006 512 2 SIM card holder

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SIM340C Hardware Design

Table 20: Pin description (Amphenol SIM card holder)

Pin Signal Description

SIM Card Power supply, it can identify automatically the SIM

C1

SIM_VDD

Card power mode, one is 3.0V±10%, and another is

1.8V±10%. Current is about 10mA.

C2
C3
C5
C6
C7

SIM_RST SIM Card Reset.

SIM_CLK SIM Card Clock.

GND Connect to GND.

VPP Not connect.

SIM_DATA SIM Card data I/O.

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30:Molex 91228 SIM card holder

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SIM340C Hardware Design

Table 21: 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
C4
C5
C6
C7
C8

SIM_RST SIM Card Reset.

SIM_CLK SIM Card Clock.

GND Connect to GND.

GND Connect to GND.

VPP Not connect.

SIM_DATA SIM Card data I/O.

SIM_PRESENCE Detect SIM Card Presence

Notes: Implement SIM Card Presence function must select 8 pin SIM Card Holder, and use AT
command enable SIM Card Presence detect.

3.13 LCD display interface

SIM340C provides a serial LCD display interface that supports serial communication with LCD

device. 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.

Table 17: PIN definition of the LCD interface

Name Pin Function

DISP_CS 38 Display data output

DISP_CLK 40 Display clock for LCD

DISP_DATA 42 Display enable

DISP_D/C 44 Display data or command select

DISP_RST 46 LCD reset

Note: This function is not supported in the default firmware.There must be some special
firmware if you want. Please contact SIMCom for more details.

3.14 ADC

SIM340C provides 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. We can use AT command “AT+CADC” to read the voltage value added on

ADC0. For detail of this AT command, please refer to document [1].

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SIM340C Hardware Design

Table 18: Pin definition of ADC

Name Pin (On Board to Board connector) Input voltage( V )

ADC0 12 0 – 2.4

Table 19: ADC specification

Min Typ Max Unit

Voltage range 0 2.4 V

ADC Resolution 16 16 bits

ADC accuracy* 0.59 mV

Sampling rate 5 Sec

3.15 Behaviors of the RI

Table 20: Behaviours of the RI

State RI respond

Standby

Voice calling Change LOW, then:

Data calling Change LOW, then：

HIGH

（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.

（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, the RI on the board-to-board connector will maintain high.

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SIM340C Hardware Design

However, 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

Figure 31: SIM340C Services as Receiver

Figure 32: SIM340C Services as caller

Ring

3.16 Network status indication

The NETLIGHT on the Board to Board connector can be used to drive a network status indication

LED. The working state of this pin is listed in following table:

Table 21: Working state of the NETLIGHT

State SIM340C function

Off SIM340C is not running

64ms On/ 800ms +50%Off SIM340C does not find the network

64ms On/ 3000ms +50%Off SIM340C find the network

64ms On/ 300ms +50% Off GPRS communication

We provide a reference circuit for you, shown as following figure:

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SIM340C Hardware Design

VBAT

MODULE

300R

4.7K

NETLIGHT

47K

Figure 33: Reference circuit of the NETLIGHT

3.17 General purpose input & output (GPIO)

SIM340C provides a limited number of General Purpose Input/Output signal pins.

Table 22: Pin definition of the GPIO

Name Pin Function

STATUS 19 The Status indication of the module，General Purpose Output Port

GPIO0 21 General Purpose Input/Output Port

GPIO1 35 General Purpose Input/Output Port

Note: This function is not supported in the default firmware. There must be special firmware if
you require. Please contact SIMCom for more details

3.18 Keypad interface

The keypad interface consists of 5 keypad column outputs and 5 keypad row inputs. The basic

configuration is 5 keypad columns and 5 keypad rows, giving 25 keys, plus the 5 additional keys

(i.e. where a keypad row is pulled low regardless of which column is enabled).

28: Pin definition of the keypad interface

Table

KBC1 20

Name Pin Function

KBC2 22
KBC0 18

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SIM340C Hardware Design

KBC3 24

KBC4 26

KBR0 28

KBR1 30

KBR2 32

Keypad matrix row

KBR3 34

KBR4 36

The keypad interface allows a direct external matrix connection. A typical recommended circuit

about the keypad is as shown in the following figure. The GND column is added for the additional

5 keys.

Figure 16: Reference circuit of the keypad interface

Note: This function is not supported in the default firmware. There must be special firmware if
you want. Please contact SIMCom for more details.

4 Antenna interface

The RF interface has an impedance of 50Ω. To suit the physical design of individual applications

SIM340C offers alternatives:

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SIM340C Hardware Design

z Recommended approach: antenna connector on the component side of the PCB
z Antenna pad and grounding plane placed on the bottom side.

To minimize the loss on the RF cable, it need be very careful to choose RF cable. We recommend

the insertion loss should be meet following requirement:

z GSM850/EGSM900<1dB
z DCS1800/PCS1900<1.5dB

4.1 Antenna installation

4.1.1 Antenna connector

SIM340C uses MURATA’s MM9329-2700RA1 RF connector on the module side, we recommend

user use MURATA’s MXTK92XXXXX as matching connector on the application side. Please

refer to appendix for detail info about MURATA’s MXTK92XXXXX.

4.1.2 Antenna pad

The antenna can be soldered to the pad, or attached via contact springs. To help you to ground the

antenna, SIM340C comes with a grounding plane located close to the antenna pad.

SIM340C material properties:

SIM340C PCB Material: FR4

Antenna pad: Gold plated pad
Antenna pad soldering temperature: we recommend 350℃.

Note: The soldering time for antenna pad and GND pad are different, less than 3s for antenna
pad and less than 10s for GND pad.

4.2 Module RF output power

Table23:SIM340CconductedRFoutputpower

Frequency Max Min

GSM850 33dBm ±2db 5dBm±5db

EGSM900 33dBm ±2db 5dBm±5db

DCS1800 30dBm ±2db 0dBm±5db

PCS1900 30dBm ±2db 0dBm±5db

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4.3 Module RF receive sensitivity

Table 30: SIM340C conducted RF receive sensitivity

Frequency Receive sensitivity

GSM850 < -106dBm

EGSM900 < -106dBm

DCS1800 < -106dBm

PCS1900 < -106dBm

4.4 Module operating frequencies

Table31:SIM340Coperating frequencies

Frequency Receive Transmit

GSM850 869 ～ 894MHz 824 ～ 849 MHz

EGSM900 925 ～ 960MHz 880 ～ 915MHz

DCS1800 1805 ～ 1880MHz 1710 ～ 1785MHz

PCS1900 1930 ～ 1990MHz 1850 ～ 1910MHz

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SIM340C 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 SIM340C

are listed in following table:

Table 32: Absolute maximum ratings

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 following table:

Table 33: SIM340C operating temperature

Parameter Min Typ Max Unit

Ambient temperature -30 25 80 ℃

Restricted operation* -40 to -30 80 to 85 ℃

Storage temperature -45 90 ℃

* SIM340C does work, but deviations from the GSM specification may occur, For example, the

frequency error or the phase error will be large.

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5.3 Power supply ratings

Table 34: SIM340C power supply ratings

Parameter Description Conditions Min Typ Max Unit

VBAT Supply voltage Voltage must stay within the

min/max values, including

voltage drop, ripple, and spikes.

Voltage drop

during transmit

Normal condition, power control

level for Pout max

burst

Voltage ripple Normal condition, power control

level for Pout max

@ f<200kHz

@ f>200kHz

I

VBAT

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,2Tx)

GSM850/EGSM 900

DCS1800/ PCS1900

3.4 4.0 4.5 V

400 mV

50

mV

2

35

2.5

23

23

260

200

470

uA

mA

mA

mA

mA

340

Peak supply

DATA mode, GPRS (4 Rx,1Tx)

GSM850/EGSM 900

DCS1800/ PCS1900

Power control level for Pout max 2 A

275

220

mA

current (during

transmission slot

every 4.6ms)

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5.4 Current consumption

Please refer to the following table for the values of current consumption.

Table 24: SIM340C current consumption

Voice Call

GSM 850/EGSM 900 @power level #5 <350mA,Typical 260mA

@power level #10,Typical 130mA

@power level #19,Typical 86mA

DCS 1800/ PCS 1900 @power level #0 <300mA,Typical 200mA

@power level #10,Typical 87mA

@power level #15,Typical 80mA

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

@power level #19,Typical 84mA

DCS 1800/ PCS 1900 @power level #0 <300mA,Typical 200mA

@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 470mA

@power level #10,Typical 225mA

@power level #19,Typical 142mA

DCS1800/ PCS1900 @power level #0 <450mA,Typical 340mA

@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

DCS 1800/ PCS 1900 @power level #0 <300mA,Typical 220mA

@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.

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SIM340C Hardware Design

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 SIM340C module.

Despite of this, we have equipped some clamp diodes to protect most lines of SIM340C from over

voltage. And the measured values are shown as the following table:

Table25: The ESD endure statue measured table (Temperature: 25℃, Humidity:45% )

Part Contact discharge Air discharge

VBAT,GND ±4KV ±8KV

KBR0-4,KBC0-4, NETLIGHT ±1KV ±2KV

Antenna port ±4KV ±8KV

Other port ±4KV ±8KV

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SIM340C Hardware Design

6 Mechanics

This chapter describes the mechanical dimensions of SIM340C.

6.1 Mechanical dimensions of SIM340C

Following shows the Mechanical dimensions of SIM340C (top view and side view).

Figure 17: Mechanical dimensions of SIM340C（Unit: mm）



Figure 18:Recommened PCB Layout（Unit: mm）

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SIM340C Hardware Design

6.2 Mounting SIM340C onto the application platform

Use the connector ASTRON1491060-09T-R and four mounting pads to fix the SIM340C onto

customer platform.

6.3 Board to Board connector

We recommend ASTRON Company’s1491060-09T-R and 1590060-09T-R as the board-to-board

connector. This high density SMT connector is designed for parallel PCB-to-PCB applications.

6.3.1 Mechanical dimensions of the ASTRON 1590060-09T-R

Figure 37: ASTRON1590060-09T-R Board to Board connector

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SIM340C Hardware Design

Figure 38: ASTRON Board to Board connector physical photo

NOTE:
The connector ASTRON ASTRON1491060-09T-R is used in pin side (SIM340C module) and
1590060-09T-R is used in socket side (user side).

6.4 RF adapter cabling

The RF connector in module side is Murata Company Microwave Coaxial Connectors

MM9329-2700RA1, it makes a pair with Murata Company RF connector MXTK. It is have high

performance with wide frequency range, surface mountable and reflow solderable. Following is

parameter. Certainly you can visit http://www.murata.com/

for more information.

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SIM340C Hardware Design



Figure 39: MM9329-2700B



Figure 40: RF connector MXTK

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SIM340C Hardware Design

For more information about the connector, please visit http://www.murata.com/

Figure 41: Bottom view of SIM340C

6.5 PIN assignment of SIM340C Board to Board connector

Table 26: Connection diagrams

PIN NO. PIN NAME I/O PIN NO. PIN NAME I/O
1
3
5
7
9
11
13
15
17
19

VBAT I/O

VBAT I/O

VBAT I/O

VBAT I/O

VBAT I/O

VCHG I

TEMP_BAT I

VDD_EXT O

PWRKEY I

STATUS O

2
4
6
8
10
12
14
16
18
20

GND

GND

GND

GND

GND

ADC0 I

VRTC I/O

NETLIGHT O

KBC0 O

KBC1 O

21
23
25
27
29

SIM340C_HD_V1.04 18.03.2009

GPIO0 I/O

BUZZER O

SIM_VDD O

SIM_RST O

SIM_DATA I/O

22
24
26
28
30

67

KBC2 O

KBC3 O

KBC4 O

KBR0 I

KBR1 I

SIM340C Hardware Design

31
33
35
37
39
41
43
45
47
49
51
53
55
57
59

SIM_CLK O

SIM_PRESENCE I

GPIO1 I/O

DCD O

DTR I

RXD I

TXD O

RTS I

CTS O

RI O

AGND

SPK1P O

SPK1N O

SPK2P O

SPK2N O

32
34
36
38
40
42
44
46
48
50
52
54
56
58
60

KBR2 I

KBR3 I

KBR4 I

DISP_CS O

DISP_CLK O

DISP_DATA I/O

DISP_D/C O

DISP_RST O

DBG_RXD I

DBG_TXD O

AGND

MIC1P I

MIC1N I

MIC2P I

MIC2N I

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Contact us:
Shanghai SIMCom Wireless Solutions Ltd

Building A，SIM Technology Building，No.633，Jinzhong Road，Changning District，
Shanghai P.R. China 200335
Tel: [phone]
Fax: [phone]
URL: www.sim.com/wm