SimTech SIMCom SIM800 Supplement

SIM800_Hardware Design_V1.09

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SIM800_Hardware Design_V1.09 2 2016-06-30
Document Title
SIM800 Hardware Design
Version
1.09
Date
2016-06-30
Status
Release
Document Control ID
SIM800_Hardware Design_V1.09
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. 2016

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Contents
1. Introduction................................................................................................................................................. 10
2. SIM800 Overview........................................................................................................................................ 10
2.1. SIM800 Key Features............................................................................................................................. 10
2.2. Operating Modes .................................................................................................................................... 12
2.3. SIM800 Functional Diagram.................................................................................................................. 13
3. Package Information................................................................................................................................... 14
3.1. Pin Out Diagram..................................................................................................................................... 14
3.2. Pin Description....................................................................................................................................... 15
3.3. Package Dimensions............................................................................................................................... 18
4. Application Interface .................................................................................................................................. 20
4.1. Power Supply.......................................................................................................................................... 20
4.1.1. Power Supply Pin................................................................................................................................ 21
4.1.2. Monitoring Power Supply................................................................................................................... 22
4.2. Power on/off SIM800............................................................................................................................. 22
4.2.1. Power on SIM800 ............................................................................................................................... 22
4.2.2. Power off SIM800............................................................................................................................... 23
4.2.3. Reset Function..................................................................................................................................... 25
4.3. Power Saving Mode................................................................................................................................ 26
4.3.1. Function Mode.................................................................................................................................... 26
4.3.2. Sleep Mode (AT+CSCLK=1) ............................................................................................................. 26
4.3.3. Wake Up SIM800 from Sleep Mode (AT+CSCLK=1) ...................................................................... 27
4.4. RTC Backup........................................................................................................................................... 27
4.5. Serial Port and USB Interface ................................................................................................................ 28
4.5.1 Function of Serial Port ........................................................................................................................ 29
4.5.2 Serial Port............................................................................................................................................ 29
4.5.3 USB Interface...................................................................................................................................... 31
4.5.4 Software Upgrade and Debug............................................................................................................. 32
4.6. RI Behaviors........................................................................................................................................... 33
4.7. Audio Interfaces ..................................................................................................................................... 34
4.7.1. Speaker Interfaces Configuration........................................................................................................ 35
4.7.2. Microphone Interfaces Configuration................................................................................................. 35
4.7.3. Audio Electronic Characteristic .......................................................................................................... 35
4.7.4. TDD .................................................................................................................................................... 36
4.8. Bluetooth ................................................................................................................................................ 36
4.9. SIM Card Interface................................................................................................................................. 36
4.9.1. SIM Card Application ......................................................................................................................... 37
4.9.2. SIM Card Design Consideration......................................................................................................... 38
4.9.3. Design Considerations for SIM Card Holder...................................................................................... 38
4.10. PCM Interface ........................................................................................................................................ 40
4.10.1. PCM Interface.................................................................................................................................. 41
4.11. Keypad Interface .................................................................................................................................... 41
4.12. I2C BUS ................................................................................................................................................. 44
4.13. General Purpose Input/Output (GPIO)................................................................................................... 44
4.14. ADC........................................................................................................................................................ 45

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4.15. PWM ...................................................................................................................................................... 45
4.16. Network Status Indication ...................................................................................................................... 46
4.17. Operating Status Indication .................................................................................................................... 47
4.18. KPLED................................................................................................................................................... 47
4.19. RF Synchronization Signal..................................................................................................................... 48
4.20. Antenna Interface ................................................................................................................................... 48
4.20.1. GSM Antenna Interface................................................................................................................... 49
4.20.2. Bluetooth Antenna Interface............................................................................................................ 50
5. PCB Layout.................................................................................................................................................. 51
5.1 PIN Assignment...................................................................................................................................... 51
5.2 Principle of PCB Layout......................................................................................................................... 51
5.2.1 Antenna............................................................................................................................................... 51
5.2.2. Power Supply...................................................................................................................................... 51
5.2.3 SIM Card Interface.............................................................................................................................. 51
5.2.4 Audio Interface.................................................................................................................................... 52
5.2.5 Others.................................................................................................................................................. 52
5.3 Recommended PCB Layout ................................................................................................................... 52
6. Electrical, Reliability and Radio Characteristics ..................................................................................... 53
6.1 Absolute Maximum Ratings................................................................................................................... 53
6.2 Recommended Operating Conditions..................................................................................................... 53
6.3 Digital Interface Characteristics............................................................................................................. 53
6.4 SIM Card Interface Characteristics ........................................................................................................ 54
6.5 SIM_VDD Characteristics...................................................................................................................... 54
6.6 VDD_EXT Characteristics..................................................................................................................... 54
6.7 VRTC Characteristics............................................................................................................................. 54
6.8 Current Consumption (VBAT=4V)........................................................................................................ 55
6.9 Electro-Static Discharge......................................................................................................................... 56
6.10 Radio Characteristics.............................................................................................................................. 56
6.11 Module RF Receive Sensitivity.............................................................................................................. 57
6.12 Module Operating Frequencies .............................................................................................................. 57
7. Manufacturing............................................................................................................................................. 58
7.1. Top and Bottom View of SIM800.......................................................................................................... 58
7.2. Typical Solder Reflow Profile................................................................................................................ 58
7.3. The Moisture Sensitivity Level .............................................................................................................. 59
7.4. Baking Requirements ............................................................................................................................. 59
8. Appendix...................................................................................................................................................... 60
I. Related Documents................................................................................................................................. 60
II. Terms and Abbreviations........................................................................................................................ 61
III. Safety Caution ........................................................................................................................................ 63

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Table Index
TABLE 1: SIM800 KEY FEATURES..............................................................................................................................10
TABLE 2: CODING SCHEMES AND MAXIMUM NET DATA RATES OVER AIR INTERFACE............................12
TABLE 3: OVERVIEW OF OPERATING MODES........................................................................................................12
TABLE 4: PIN DESCRIPTION .......................................................................................................................................15
TABLE 5: RECOMMENDED ZENER DIODE ..............................................................................................................20
TABLE 6: ELECTRONIC CHARACTERISTIC OF THE RESET PIN..........................................................................25
TABLE 7: THE CURRENT CONSUMPTION OF FUNCTION MODES (BS-PA-MFRMS=5)....................................26
TABLE 8: SERIAL PORT AND USB PIN DEFINITION...............................................................................................28
TABLE 9: SERIAL PORT CHARACTERISTICS...........................................................................................................28
TABLE 10: USB_VBUS OPERATION VOLTAGE........................................................................................................32
TABLE 11: RI BEHAVIORS ...........................................................................................................................................33
TABLE 12: AUDIO INTERFACE DEFINITION............................................................................................................34
TABLE 13: MICROPHONE INPUT CHARACTERISTICS...........................................................................................35
TABLE 14: AUDIO OUTPUT CHARACTERISTICS....................................................................................................36
TABLE 15: SIM PIN DEFINITION.................................................................................................................................37
TABLE 16: PIN DESCRIPTION (MOLEX SIM CARD HOLDER) ..............................................................................39
TABLE 17: PIN DESCRIPTION (AMPHENOL SIM CARD HOLDER).......................................................................40
TABLE 18: PCM PIN DEFINITION...............................................................................................................................40
TABLE 19: PCM SPECIFICATION................................................................................................................................41
TABLE 20: PIN DEFINITION OF THE KEYPAD INTERFACE...................................................................................43
TABLE 21: PIN DEFINITION OF THE I2C...................................................................................................................44
TABLE 22: PIN DEFINITION OF THE GPIO................................................................................................................44
TABLE 23: PIN DEFINITION OF THEADC.................................................................................................................45
TABLE 24: ADC SPECIFICATION ................................................................................................................................45
TABLE 25: PIN DEFINITION OF THE PWM ...............................................................................................................45
TABLE 26: PWM OUTPUT CHARACTERISTICS .......................................................................................................46
TABLE 27: PWM MULTIPLEX FUNCTION.................................................................................................................46
TABLE 28: PIN DEFINITION OF THE NETLIGHT.....................................................................................................46
TABLE 29: STATUS OF THE NETLIGHT PIN..............................................................................................................46
TABLE 30: PIN DEFINITION OF THE STATUS...........................................................................................................47
TABLE 31: PIN DEFINITION OF THE KPLED............................................................................................................47
TABLE 32: KPLED SPECIFICATION............................................................................................................................48
TABLE 33: DEFINITION OF THE RF_SYNC PIN........................................................................................................48
TABLE 34: RECOMMENDATION OF ESD COMPONENT.........................................................................................49
TABLE 35: ABSOLUTE MAXIMUM RATINGS...........................................................................................................53
TABLE 36: RECOMMENDED OPERATING CONDITIONS.......................................................................................53
TABLE 37: DIGITAL INTERFACE CHARACTERISTICS...........................................................................................53
TABLE 38: SIM CARD INTERFACE CHARACTERISTIC..........................................................................................54
TABLE 39: SIM_VDD CHARACTERISTICS................................................................................................................54
TABLE 40: VDD_EXT CHARACTERISTICS ...............................................................................................................54
TABLE 41: VRTC CHARACTERISTICS.......................................................................................................................54
TABLE 42: CURRENT CONSUMPTION ......................................................................................................................55
TABLE 43: THE ESD CHARACTERISTICS (TEMPERATURE: 25°C , HUMIDITY: 45 %).......................................56
TABLE 44: GSM 900 AND GSM 850 CONDUCTED RF OUTPUT POWER ..............................................................56
TABLE 45: DCS 1800 AND PCS 1900 CONDUCTED RF OUTPUT POWER.............................................................57
TABLE 46: CONDUCTED RF RECEIVE SENSITIVITY.............................................................................................57

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TABLE 47: OPERATING FREQUENCIES.....................................................................................................................57
TABLE 48: MOISTURE CLASSIFICATION LEVELAND FLOOR LIFE ...................................................................59
TABLE 49: BAKING REQUIREMENTS .......................................................................................................................59
TABLE 50: RELATED DOCUMENTS...........................................................................................................................60
TABLE 51: TERMS AND ABBREVIATIONS................................................................................................................61
TABLE 52: SAFETY CAUTION.....................................................................................................................................63

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Figure Index
FIGURE 1: SIM800 FUNCTIONAL DIAGRAM ...........................................................................................................13
FIGURE 2: SIM800 PIN OUT DIAGRAM (TOPVIEW)...............................................................................................14
FIGURE 3: DIMENSIONS OF SIM800 (UNIT: MM)....................................................................................................18
FIGURE 4: RECOMMENDED PCB FOOTPRINT OUTLINE (UNIT: MM)................................................................19
FIGURE 5: REFERENCE CIRCUIT OF THE VBAT INPUT.........................................................................................20
FIGURE 6: REFERENCE CIRCUIT OF THE POWER SUPPLY..................................................................................20
FIGURE 7: REFERENCE CIRCUIT OF THE DC-DC POWER SUPPLY.....................................................................21
FIGURE 8: VBAT VOLTAGE DROP DURING TRANSMIT BURST...........................................................................21
FIGURE 9: THE MINIMAL VBAT VOLTAGE REQUIREMENTAT VBAT DROP ....................................................22
FIGURE 10: POWER ON/OFF MODULE USING TRANSISTOR ...............................................................................22
FIGURE 11: POWER ON/OFF MODULE USING BUTTON........................................................................................22
FIGURE 12: TIMING OF POWER ON MODULE.........................................................................................................23
FIGURE 13: TIMING OF POWER OFF SIM800 BY PWRKEY...................................................................................24
FIGURE 14: RESET CIRCUIT........................................................................................................................................25
FIGURE 15: RESET TIMING SEQUENCE....................................................................................................................26
FIGURE 16: RTC SUPPLY FROM CAPACITOR...........................................................................................................27
FIGURE 17: RTC SUPPLY FROM NON-CHARGEABLE BATTERY .........................................................................27
FIGURE 18: RTC SUPPLY FROM RECHARGEABLE BATTERY ..............................................................................28
FIGURE 19: CONNECTION OF THE SERIAL PORT...................................................................................................30
FIGURE 20: LEVEL CONVERTING BY RESISTOR....................................................................................................30
FIGURE 21: ISOLATION CIRCUIT BY DIODES .........................................................................................................31
FIGURE 22: TX LEVEL CONVERTING BY TRANSISTOR........................................................................................31
FIGURE 23: RX LEVEL CONVERTING BY TRANSISTOR .......................................................................................31
FIGURE 24: USB REFERENCE CIRCUIT ....................................................................................................................32
FIGURE 25: CONNECTION FOR SOFTWARE UPGRADING....................................................................................33
FIGURE 26: RI BEHAVIOUR OF VOICE CALLING AS A RECEIVER......................................................................34
FIGURE 27: RI BEHAVIOUR OF DATA CALLING AS A RECEIVER........................................................................34
FIGURE 28: RI BEHAVIOUR OF URC OR RECEIVE SMS ........................................................................................34
FIGURE 29: RI BEHAVIOUR AS A CALLER ...............................................................................................................34
FIGURE 30: SPEAKER REFERENCE CIRCUIT ..........................................................................................................35
FIGURE 31: MICROPHONE REFERENCE CIRCUIT..................................................................................................35
FIGURE 32: REFERENCE CIRCUIT OF THE 8-PIN SIM CARD HOLDER...............................................................37
FIGURE 33: REFERENCE CIRCUIT OF THE 6-PIN SIM CARD HOLDER...............................................................38
FIGURE 34: MOLEX 91228 SIM CARD HOLDER ......................................................................................................39
FIGURE 35: AMPHENOL C707 10M006 512 SIM CARD HOLDER...........................................................................40
FIGURE 36: PCM REFERENCE CIRCUIT....................................................................................................................41
FIGURE 37: TRADITIONAL KEYPAD REFERENCE CIRCUIT.................................................................................42
FIGURE 38: EXTENDED KEYPAD REFERENCE CIRCUIT......................................................................................42
FIGURE 39: ENHANCE THE ESD PERFORMANCE OF KEYPAD CIRCUIT...........................................................43
FIGURE 40: KEYPAD DETECTED ...............................................................................................................................43
FIGURE 41: GPIO TIMING SEQUENCES....................................................................................................................45
FIGURE 42: REFERENCE CIRCUIT OF PWM DRIVE BUZZER...............................................................................46
FIGURE 43: REFERENCE CIRCUIT OF NETLIGHT ..................................................................................................47
FIGURE 44: KPLED DRIVER REFERENCE CIRCUIT................................................................................................48
FIGURE 45: RF_SYNC SIGNAL DURING TRANSMIT BURST ................................................................................48
FIGURE 46: GSM ANTENNA MATCHING CIRCUIT .................................................................................................49

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FIGURE 47: GSM SIMPLEANTENNA MATCHING CIRCUIT ..................................................................................49
FIGURE 48: BLUETOOTH ANTENNA MATCHING CIRCUIT ..................................................................................50
FIGURE 49: RECOMMENDED PCB LAYOUT............................................................................................................52
FIGURE 50: TOPAND BOTTOM VIEW OF SIM800...................................................................................................58
FIGURE 51: TYPICAL SOLDER REFLOW PROFILE .................................................................................................58

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Version History
Date
Version
Description of change
Author
2013-07-29
1.00
Origin
Ma Honggang
Teng Lili
2013-08-05
1.01
Update RESET pin parameter;
Update figure 12, 13, 15.
Ma Honggang
2013-08-21
1.02
Update figure 3 and figure 23;
Update chapter 7.3;
Ma Honggang
2014-01-17
1.03
Update table32, correct NETLIGHT to PIN 52;
Ma Honggang
2014-03-11
1.04
Update table 11
Ma Honggang
2014-03-25
1.05
Update figure 32 and figure 33, The 100nF capacitor changed;
Ma Honggang
2014-07-18
1.06
Update figure 12 and 13, timing of VDD_EXT changed;
Update the baudrate that SIM800 supports;
Rename some pin name to follow the SIMCom naming rules;
Uptade table 6, table9;
Add GPIO timing sequences of figure 43;
Update figure 51;
Ma Honggang
2014-12-01
1.07
Update table 45
WuChengbing
2015-03-05
1.08
Update table 5,10and 12;
Update figure 51;
Update the chapter power supply;
Update the chapter bluetooth;
Update the frequency of PWM that SIM800 supports;
WuChengbing
2016-06-21
1.09
Update figure 48 and 49,add a TVS;
Update Table 38, add recommendation ESD component
Delete the automatic power off function related to temperature
LiuQiang
Zhang xiuyu

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1. Introduction
This document describes SIM800 hardware interface in great detail.
This document can help user to quickly understand SIM800 interface specifications, electrical and mechanical
details. With the help of this document and other SIM800 application notes, user guide, users can use SIM800 to
design various applications quickly.
2. SIM800 Overview
Designed for global market, SIM800 is a quad-band GSM/GPRS module that works on frequencies GSM
850MHz, EGSM 900MHz, DCS 1800MHz and PCS 1900MHz. SIM800 features GPRS multi-slot class 12/ class
10 (optional) and supports the GPRS coding schemes CS-1, CS-2, CS-3 and CS-4.
With a tiny configuration of 24*24*3mm, SIM800 can meet almost all the space requirements in users’
applications, such as M2M, smart phone, PDA and other mobile devices.
SIM800 has 68 SMT pads, and provides all hardware interfaces between the module and customers’ boards.
Support up to 5*5*2 Keypads.
One full function UART port, and can be configured to two independent serial ports.
One USB port can be used as debugging and firmware upgrading.
Audio channels which include a microphone input and a receiver output.
Programmable general purpose input and output.
One SIM card interface.
Support Bluetooth function.
Support one PWM.
PCM
SIM800 is designed with power saving technique so that the current consumption is as low as 1.2mA in sleep
mode.
SIM800 integrates TCP/IP protocol and extended TCP/IPAT commands which are very useful for data transfer
applications. For details about TCP/IP applications, please refer to document [11].
2.1. SIM800 Key Features
Table 1: SIM800 key features
Feature
Implementation
Power supply
3.4V ~4.4V
Power saving
Typical power consumption in sleep mode is 1.2mA ( BS-PA-MFRMS=9 )
Frequency bands
SIM800 Quad-band: GSM 850, EGSM 900, DCS 1800, PCS 1900. SIM800 can
search the 4 frequency bands automatically. The frequency bands also can be set
by AT command “AT+CBAND”. For details, please refer to document [1].
Compliant to GSM Phase 2/2+
Transmitting power
Class 4 (2W):GSM850,EGSM900
Class 1 (1W):DCS1800,PCS1900
GPRS connectivity
GPRS multi-slot class 12（default）

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GPRS multi-slot class 1~12 (option)
Temperature range
Normal operation:-40°C ~ +85°C
Storage temperature -45°C ~ +90°C
GPRS
GPRS data downlink transfer: max. 85.6 kbps
GPRS data uplink transfer: max. 85.6 kbps
Coding scheme: CS-1, CS-2, CS-3 and CS-4
PAP protocol for PPP connect
Integrate the TCP/IP protocol.
Support Packet Broadcast Control Channel (PBCCH)
CSD
Support CSD transmission
CSD transmission rates:2.4,4.8,9.6,14.4 kbps
USSD
Unstructured Supplementary Services Data (USSD) support
SMS
MT, MO, CB, Text and PDU mode
SMS storage: SIM card
SIM interface
Support SIM card: 1.8V, 3V
Antenna Interface
Antenna pad
Audio features
Speech codec modes:
Half Rate (ETS 06.20)
Full Rate (ETS 06.10)
Enhanced Full Rate (ETS 06.50 / 06.60 / 06.80)
Adaptive multi rate (AMR)
Echo Cancellation
Noise Suppression
Serial port and USB
interface
Serial port:
Full modem interface with status and control lines, unbalanced, asynchronous.
1200bps to 460800bps
Can be used for AT commands for data stream
Support RTS/CTS hardware handshake and software ON/OFF flow control
Multiplex ability according to GSM 07.10 Multiplexer Protocol
Autobauding supports baud rate from 1200 bps to 115200bps
USB interface:
Can be used as debugging and firmware upgrading
Phonebook
management
Support phonebook types: SM, FD, LD, RC, ON, MC
SIM application
toolkit
GSM 11.14 Release 99
Real time clock
Support RTC
Alarm function
Can be set by AT command
Physical
characteristics
Size:24*24*3mm
Weight:3.2g
Firmware upgrade
Firmware upgrading by serial port or USB interface(recommend to use USB port)

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Table 2: 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. Operating Modes
The table below summarizes the various operating modes of SIM800.
Table 3: Overview of operating modes
Mode
Function
Normal
operation
GSM/GPRS
SLEEP
Module will automatically go into sleep mode if the conditions of sleep
mode are enabling and there is no on air or 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.
In sleep mode, the module can still receive paging message and SMS.
GSM
IDLE
Software is active. Module registered to the GSM network, and the
module is ready to communicate.
GSM
TALK
Connection between two subscribers is in progress. 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 transfer (PPP or TCP or UDP) in progress. In this
case, power consumption is related with network settings (e.g. power
control level); uplink/downlink data rates and GPRS configuration (e.g.
used multi-slot settings).
Power off
Normal Power off by sending the AT command “AT+CPOWD=1” or using the PWRKEY.
The power management unit shuts down the power supply for the baseband part of the
module, and only the power supply for the RTC is remained. Software is not active. The
serial port is not accessible. Power supply (connected to VBAT) remains applied.
Minimum
functionality
mode
AT command “AT+CFUN” can be used to set the module to a minimum functionality
mode without removing the power supply. In this mode, the RF part of the module will not
work or the SIM card will not be accessible, or both RF part and SIM card will be closed,
and the serial port is still accessible. The power consumption in this mode is lower than
normal mode.

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2.3. SIM800 Functional Diagram
The following figure shows a functional diagram of SIM800:
GSM baseband engine
PMU
RF part
Antenna interfaces
Other interfaces
Analog
Baseband
Digital
Baseband
Power Management Unit
Radio
Frequency
Power
Supply
Analog
Interface
Digital
Interface
UART
SIM
GPIOs
RTC
Audio
ADC
GSM
BT
USB
KEYPAD
PCM
Figure 1: SIM800 functional diagram

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3. Package Information
3.1. Pin Out Diagram
Figure 2: SIM800 pin out diagram (Top view)

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3.2. Pin Description
Table 4: Pin description
Pin name
Pin
number
I/O
Description
Comment
Power supply
VBAT
55,56,57
I
SIM800 supplies 3 VBAT pins, and
the power range is from 3.4V to 4.4V.
Power supply should provide
sufficient current so that the module
can work normally; the peak current
is nearly 2A.
Zener diode is Strongly
recommended to anti surge
on VBAT.
VRTC
26
I/O
Power supply for RTC
It is recommended to
connect VRTC to a battery
or a capacitor (e.g. 4.7uF).
VDD_EXT
15
O
2.8V power output
Keep floating if unused.
GND
2,17,18,29,3
9,45,46,54,5
8,59,61,62,6
3,64,65
Ground
GND for VBAT
recommend to use 62, 63,
64, 65 pin
.
Power on/off
PWRKEY
1
I
PWRKEY should be pulled low at
least 1.2 second and then released to
power on/down the module.
Internally pulled up to
VBAT.
Audio interface
MICP
19
I
Differential audio input
Keep floating if unused.
MICN
20
SPKP
21
O
Differential audio output
SPKN
22
PCM interface
PCM_OUT
6
O
PCM interface for audio
Keep floating if unused.
PCM_IN
12
I
PCM_SYNC
14
O
PCM_CLK
68
I
Keypad interface
KBC4
47
I
Support up to 50 buttons (5*5*2)
Keep floating if unused.
(KBC0 can not be pulled
down).
KBC3
48
I
KBC2
49
I
KBC1
50
I
KBC0
51
I
KBR4
40
O

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KBR3
41
O
KBR2
42
O
KBR1
43
O
KBR0
44
O
GPIO
GPIO17
11
I/O
Programmable general purpose input
and output.
GPIO19
13
I/O
NETLIGHT
52
O
Network status
Can not multiplex with
GPIO function.
STATUS
66
O
Power on status
Serial port
DTR
3
I
Data terminal ready
Keep floating if unused.
RI
4
O
Ring indicator
DCD
5
O
Data carrier detect
CTS
7
O
Clear to send
RTS
8
I
Request to send
TXD
9
O
Transmit data
RXD
10
I
Receive data
USB interface
USB_VBUS
24
I
Debug and firmware upgrading
Keep floating if unused.
USB_DP
27
I/O
USB_DN
28
I/O
ADC
ADC
25
I
10 bit general analog to digital
converter
Keep floating if unused.
PWM
PWM0
35
O
Pulse-width modulation, multiplex
with GPIO.
Keep floating if unused.
PWM1
36
O
Pulse-width modulation, multiplex
with GPIO.
I2C
SDA
37
I/O
I2C serial bus data
Internal pulled up to 2.8V
via 4.7KΩ
SCL
38
O
I2C serial bus clock
SIM interface
SIM_VDD
30
O
Voltage supply for SIM card. Support
1.8V or 3V for SIM card
All signals of SIM
interface should be
protected against ESD with
a TVS diode array.
SIM_DATA
31
I/O
SIM data input/output
SIM_CLK
32
O
SIM clock
SIM_RST
33
O
SIM reset
SIM_DET
34
I
SIM card detection
Antenna
GSM_ANT
60
I/O
GSM antenna port
Impendence must be
controlled to 50Ω.

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BT_ANT
53
I/O
Bluetooth antenna port
Impendence must be
controlled to 50Ω.
RF synchronization
RF_SYNC
67
O
RF burst synchronous signal
Do not pull up
Other signal
RESET
16
I
Reset input(Active low)
KPLED
23
I
Drive keypad backlight

Smart Machine Smart Decision
SIM800_Hardware Design_V1.09 18 2016-06-30
3.3. Package Dimensions
Figure 3: Dimensions of SIM800 (Unit: mm)

Smart Machine Smart Decision
SIM800_Hardware Design_V1.09 19 2016-06-30
Figure 4: Recommended PCB footprint outline (Unit: mm)
Note: Keep copper out of area B and C.

Smart Machine Smart Decision
SIM800_Hardware Design_V1.09 20 2016-06-30
4. Application Interface
4.1. Power Supply
The power supply range of SIM800 is from 3.4V to 4.4V. Recommended voltage is 4.0V. The transmitting burst
will cause voltage drop and the power supply must be able to provide sufficient current up to 2A. For the VBAT
input, a bypass capacitor (low ESR) such as a 100µF is strongly recommended.
For the VBAT input, a 100uF Tantalum capacitor (CAlow ESR) and a 1uF~10uF Ceramics capacitor CBare
strongly recommended .The 33pF and 10pF capacitors can effectively eliminate the high frequency
interference. A 5.1V/500mW Zener diode is strongly recommended, the diode can prevent chip from damaging
by the voltage surge. These capacitors and Zener diode should be placed as close to SIM800 VBAT pins as
possible.
VBAT
5.1V
500mW
CACB33pF 10pF
Figure 5: Reference circuit of the VBAT input
Table 5: Recommended Zener diode
Vendor
Part number
Power(watts)
Packages
1
On semi
MMSZ5231BT1G
500mW
SOD123
2
Prisemi
PZ3D4V2H
500mW
SOD323
3
Vishay
MMSZ4689-V
500mW
SOD123
4
Crownpo
CDZ55C5V1SM
500mW
0805
The following figure is the reference design of +5V input power supply. The designed output for the power
supply is 4.1V, thus a linear regulator can be used.
Vin Vout
GND
FB
3
+
PWR_CTRL
R102
R101
VBAT
100K
43K
+C103
330uF
C104
100nF
U101 MIC29302
5
4
1
2
C101 C102
100uF 1uF
DC INPUT
R103
470Ω
On/Off
Figure 6: Reference circuit of the power supply