SimCom SIM68R Supplement

SIM68R_Hardware Design_V1.02

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SIM68R_Hardware Design_V1.02 2 2013-01-22
Document Title SIM68R Hardware Design
Version 1.02
Date 2013-01-22
Status Release
Document Control ID SIM68R_Hardware Design_V1.02
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. 2013

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SIM68R_Hardware Design_V1.02 3 2013-01-22
Contents
Contents.................................................................................................................................................................... 3
Version History........................................................................................................................................................ 7
1Introduction....................................................................................................................................................... 8
2SIM68R Overview............................................................................................................................................. 8
2.1 SIM68R Functional Diagram ................................................................................................................... 9
2.2 GNSS Performance................................................................................................................................... 9
2.3 General features...................................................................................................................................... 10
3Package Information ...................................................................................................................................... 12
3.1 Pin out Diagram...................................................................................................................................... 12
3.2 Pin Description ....................................................................................................................................... 12
3.3 Package Dimensions............................................................................................................................... 14
3.4 SIM68R Recommended PCB Decal....................................................................................................... 15
4Application Interface...................................................................................................................................... 16
4.1 Power Management ................................................................................................................................ 16
4.1.1 Power Input ......................................................................................................................................... 16
4.1.2 Starting SIM68R ................................................................................................................................. 16
4.1.3 Verification of SIM68R Start .............................................................................................................. 16
4.1.4 Power Saving Modes........................................................................................................................... 16
4.1.5 Operating Mode .................................................................................................................................. 17
4.1.5.1 Full on Mode........................................................................................................................................ 17
4.1.5.2 Sleep Mode .......................................................................................................................................... 17
4.1.6 VCC_RF.............................................................................................................................................. 17
4.2 UART Interface ...................................................................................................................................... 17
4.3 I2C interface.......................................................................................................................................... 18
4.4 Timemark Output ................................................................................................................................... 18
4.5 DET_N ................................................................................................................................................... 18
4.6 A-GPS .................................................................................................................................................... 18
4.6.1 EPO ..................................................................................................................................................... 18
4.6.2 EASY MODE...................................................................................................................................... 19
4.6.3 SBAS and RTCM................................................................................................................................ 19
4.7 GNSS Antenna ....................................................................................................................................... 19
4.7.1 Antenna Interface................................................................................................................................ 20
4.7.2 GNSS Antenna Choice Consideration ................................................................................................ 20
4.7.2.1 Passive Antenna ................................................................................................................................... 20
4.7.2.2 Active Antennas................................................................................................................................... 22
4.7.2.3 Active antenna bias power ................................................................................................................... 23
4.7.3 Active antenna supervisor................................................................................................................... 23
4.7.3.1 Short circuit Detection ......................................................................................................................... 24
4.7.3.2 Open circuit Detection ......................................................................................................................... 24
5Electrical, Reliability and Radio Characteristics......................................................................................... 26
5.1 Absolute Maximum Ratings................................................................................................................... 26
5.2 Recommended Operating Conditions..................................................................................................... 26

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5.3 Electro-Static Discharge ......................................................................................................................... 27
5.4 Certification............................................................................................................................................ 27
6Manufacturing ................................................................................................................................................ 28
6.1 Top and Bottom View of SIM68R ......................................................................................................... 28
6.2 Assembly and Soldering......................................................................................................................... 28
6.3 Moisture sensitivity ................................................................................................................................ 29
6.4 ESD handling precautions ...................................................................................................................... 30
6.5 Shipment................................................................................................................................................. 30
7Reference Design............................................................................................................................................. 31
Appendix ................................................................................................................................................................ 32
A. Related Documents.......................................................................................................................................... 32
B. Terms and Abbreviations ................................................................................................................................. 32

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Table Index
TABLE 1: GNSS PERFORMANCE.................................................................................................................................. 9
TABLE 2: GENERAL FEATURES ................................................................................................................................. 10
TABLE 3: PIN DESCRIPTION ....................................................................................................................................... 12
TABLE 4: POWER SUPPLY AND CLOCK STATE ACCORDING TO OPERATION MODE..................................... 17
TABLE 5: HOST PORT MULTIPLEXED FUNCTION PINS ........................................................................................ 18
TABLE 6: ANTENNA SPECIFICATIONS...................................................................................................................... 19
TABLE 7: ABSOLUTE MAXIMUM RATINGS............................................................................................................. 26
TABLE 8: SIM68R OPERATING CONDITIONS........................................................................................................... 26
TABLE 9: SIM68R STANDARD IO FEATURES........................................................................................................... 26
TABLE 10: THE ESD ENDURE STATUE MEASURED TABLE (TEMPERATURE: 25℃, HUMIDITY:45% ) ........ 27
TABLE 11: ILLUSTRATION OF MODULE INFORMATION ...................................................................................... 28
TABLE 12: MOISTURE CLASSIFICATION LEVEL AND FLOOR LIFE ................................................................... 29
TABLE 13: RELATED DOCUMENTS ........................................................................................................................... 32
TABLE 14: TERMS AND ABBREVIATIONS................................................................................................................ 32

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Figure Index
FIGURE 1: SIM68R FUNCTIONAL DIAGRAM............................................................................................................. 9
FIGURE 2: SIM68R PIN OUT DIAGRAM (TOP VIEW) .............................................................................................. 12
FIGURE 3: SIM68R MECHANICAL DIMENSIONS (UNIT: MM) .............................................................................. 14
FIGURE 4: RECOMMENDED PCB DECAL (TOP VIEW) (UNIT: MM)..................................................................... 15
FIGURE 5: SIM68R PASSIVE ANTENNA DESIGN..................................................................................................... 21
FIGURE 6: SIM68R PASSIVE ANTENNA DESIGN (WITH EXTERNAL LNA AND SAW) ..................................... 21
FIGURE 7: SIM68R PASSIVE ANTENNA DESIGN FOR BEST PERFORMANCE ................................................... 22
FIGURE 8: SIM68R ACTIVE ANTENNA DESIGN ...................................................................................................... 22
FIGURE 9: INTERNAL SUPPLY ANTENNA BIAS VOLTAGE ................................................................................... 23
FIGURE 10: EXTERNAL SUPPLY ANTENNA BIAS VOLTAGE ................................................................................ 23
FIGURE 11: OPEN CIRCUIR DETECTION-A.............................................................................................................. 24
FIGURE 12: OPEN CIRCUIR DETECTION-B.............................................................................................................. 25
FIGURE 13: TOP AND BOTTOM VIEW OF SIM68R .................................................................................................. 28
FIGURE 14: THE RAMP-SOAK-SPIKE REFLOW PROFILE OF SIM68R ................................................................. 29
FIGURE 15: EXAMPLE APPLICATION SCHEMATIC WITH UART ......................................................................... 31

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Version History
Date Version Description of change Author
2012-10-17 V1.00 Origin Shengwu.Sun
Xiaohan.Jin
2013-01-22 V1.02 Add some features and Modify pictures Shengwu.Sun

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1Introduction
This document describes the hardware interface of the SIMCom module SIM68R，which can be used as GNSS or
A-GPS（Assisted Global Positioning System）receiver. As wide range of applications, this document will
describe them in great detail.
2SIM68R Overview
With built-in LNA, SIM68R doesn’t need external LNA. SIM68R can track as low as -165dBm signal even
without network assistance. The SIM68R has excellent low power consumption characteristic (acquisition 26mA,
tracking 21mA). SIM68R supports various location and navigation applications, including autonomous GPS,
GLONASS, GALILEO, QZSS, SBAS ranging (WAAS, EGNOS, GAGAN, MSAS), DGPS (RTCM), and A-GPS.
Key Features
The user only need to provide DC power and GPS signal, the SIM68 will output navigation solution in NMEA
protocol format. The module requires 2.8V~4.3V power supply. The host port is configurable to UART. Host data
and I/O signal levels are 2.85V CMOS compatible.
zGPS/GLONASS/Galileo receiver, supports multi-GNSS include QZSS, SBAS ranging, supports
WAAS/EGNOS/MSAS/GAGAN
z33tracking/99 acquisition-channel GNSS receiver
zSmall footprint: 17 x 22.4x 2.7mm, 28-pin LCC package
z12 multi-tone active interference cancellers (ISSCC2011 award)
zIndoor and outdoor multi-path detection and compensation
zSupports FCC E911 compliance and A-GPS
zMax fixed update rate up to 10 HZ
zAdvanced firmware features
1. Alwayslocate advanced location awareness technology
2. EPO/HotStill orbit prediction
3. EASY self-generated orbit prediction
4. supports logger function
5. supports active interference cancellation (AIC)
zPulse-per-second (PPS) GNSS time reference
1. Adjustable duty cycle
2. typical accuracy: ±10ns
zInterface
UART×2
zOperating temperature -40 ~ +85ºC
zAccuracy <2.5m CEP
zRoHS compliant

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2.1 SIM68R Functional Diagram
The following figure shows a functional diagram of the SIM68R and illustrates the main functional parts:
zThe GNSS chip
zSAW filter
zThe antenna interface
zThe communication interface
zThe control signals
Figure 1: SIM68R functional diagram
2.2 GNSS Performance
Table 1: GNSS performance
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Performance
Parameter Description Min Type Max Unit
Horizontal Position
Accuracy(1)
Autonomous <2.5 m
Without Aid 0.1 m/sVelocity
Accuracy(2) DGPS 0.05 m/s
Without Aid 0.1 m/s2 Acceleration
Accuracy DGPS 0.05 m/s2
Timing Accuracy 10 nS
Maximum Altitude 18000 m
Maximum Velocity 515 m/s
Dynamic
Performance
Maximum
Acceleration
4 G

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Hot start <1 s
Warm start 26 s
Time To First Fix(3)
Cold start 28 s
Hot start 0.7 s
Warm start 1.5 s
A-GPS TTFF(EPO
in flash mode)
Cold start 12.5 s
Autonomous
acquisition(cold start)
-148 dBm
Re-acquisition -160 dBm
Sensitivity
Tracking -167 dBm
Channels 132
Update rate 1 10 Hz
Tracking L1, CA
Code
Receiver
Protocol support
NMEA,PMTK
Acquisition 34 mA
Continuous tracking 30 mA
Sleep current <440 uA
Power
consumption-A(4)
Backup current 14 uA
(1) 50% 24hr static, -130dBm
(2) 50% at 30m/s
(3) –130 dBm, GPS&GLONASS mode
(4) Single Power supply 3.3V under GPS+GLONASS signal
2.3 General features
Table 2: General features
Parameters Value
Supply voltage VCC +2.8V~4.3V
Supply voltage ripple VCC 54 mV(RMS) max @ f = 0~3MHz
15 mV(RMS) max @ f > 3 MHz
Power consumption(acquisition) 37mA type. @ VCC=3.3 V
Power consumption(sleep) 440uA type. @ VCC=3.3 V
Storage temperature -40ºC~+85ºC
Operating temperature -40ºC~+85ºC (note 1)
VIL -0.3V~0.8V
VIH 2.0V~3.6V
VOL -0.3V~0.4V
I/O signal levels
VOH 2.4V~3.1V
I/O output sink/source capability +/- 3mA max
I/O input leakage +/- 10 uA max

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Host port UART,UART1
Other port I2C
Serial port protocol (UART) NMEA; 8 bits, no parity, 1 stop bit; 115200 baud (configurable)
TM output (1PPS) 1 pulse per second, synchronized at rising edge, pulse length 300ms
Note 1: Operation in the temperature range –40°C~ –30°C is allowed but Time-to-First-Fix performance and tracking sensitivity
may be degraded.

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3Package Information
3.1 Pin out Diagram
Figure 2: SIM68R pin out diagram (Top view)
3.2 Pin Description
Table 3: Pin description
Pin name Pin number I/O Description Comment
Power supply
VCC 6 I
Main power input, which will be used
to power the baseband and RF section
internally.
Provide clean and stable
power source to this pin.
Add a 4.7uF capacitor to
this pin for decoupling.
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V_OUT 8 O Output voltage. It Has been connected
to VCC inside the Module If unused, keep open.
VCC_RF 18 O 2.8V output power supply for active
antenna If unused, keep open.
V_ANT 19 I Antenna Bias voltage If unused ，connect to
GND
V_BACKUP 11 I The backup battery input power supply
for RTC If unused, keep open.
GND 7,13,14,15,17 Ground GND
Host port interface
SDA 1 I/O I2C data
SCL 2 I/O I2C C Clock
If unused, keep open.
TXD 3 O Serial output If unused, keep open
RXD 4 I Serial input If unused, keep open
TXD1 22 O Serial output as RTCM
RXD1 21 I Serial input as RTCM
GPIOs
EINT0 27 I
This interrupt source could act as wake
up event during power saving mode.
Provide an interrupt on either high or
low logic level or edge-sensitive
interrupt
Not supported yet, keep
open.
TIMEMARK 28 O Time Mark outputs timing pulse related
to receiver time If unused, keep open.
NRESET 10 I Reset input, active low If unused, keep open.
DET_N 20 I Active Antenna Detect If unused, keep open.
RF interface
RF_IN 16 Impendence must be
controlled to 50Ω.
I Radio antenna connection
Other interface
NC 5,12,23,24,25
,26 Not Connected
Reserved 9 Not Connected
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3.3 Package Dimensions
Following figure shows the Mechanical dimensions of SIM68R (top view, side view and bottom view).
Figure 3: SIM68R mechanical dimensions (Unit: mm)
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3.4 SIM68R Recommended PCB Decal
Figure 4: Recommended PCB decal (top view) (Unit: mm)
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4Application Interface
4.1 Power Management
4.1.1 Power Input
The power supply range is from 2.8V to 4.3V, and it should be able to provide sufficient current up to 100mA.
4.1.2 Starting SIM68R
zWhen power is first applied, SIM68R goes into operation mode.
4.1.3 Verification of SIM68R Start
System activity indication depends upon the chosen serial interface:
zWhen it is activated, SIM68R will output messages at the selected UART speed, and message types.
Note: the baud rate information can be found on the label.
4.1.4 Power Saving Modes
SIM68R supports operating modes for reduced average power consumption like sleep mode, backup mode,
periodic mode, and AlwayLocateTM mode.
zSleep mode: In this mode the receiver stays at full on power state. When this mode that can be wake up by
the host sends the command through the communication interface or external interrupt.
zBackup mode: In this mode the SIM68R must be supplied by the backup and it can help to count down the
time for backup mode. Software on host side to send the command through the communication interface
into the backup mode.
zPeriodic mode: In this mode the SIM68R enters tracking and backup mode according to the interval
configured by users in the commands.
zAlwayLocateTM mode: AlwayLocateTM is an intelligent controller of SIM68R periodic mode. Depending on
the environment and motion conditions, SIM68R can adaptive adjust the on/off time to achieve balance of
positioning accuracy and power consumption.
Note: the modes mentioned above are operated by PMTK commands, users can refer to document [3] for more information.
SIM68R provides very low leakage battery back up memory, which contains all the necessary GNSS information
for quick start up and a small amount of user configuration variables. It needs a 3V power supply for V_BACKUP
pin, and the stable operation region ranges from very light load to about 3mA.

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4.1.5 Operating Mode
Table 4: Power supply and clock state according to operation mode
Mode VCC V_BACKUP Internal LDO Main clock RTC clock
Full on on on on on on
Sleep on on on off on
Backup on on off off on
4.1.5.1 Full on Mode
The module will enter full on mode after first power up with factory configuration settings. Power consumption
will vary depending on the amount of satellite acquisitions and numbers of satellites in track. This mode is also
referenced as Full on, Full Power or Navigation mode.
Navigation is available and any configuration settings are valid as long as the VCC power supply is active. When
the power supply is off, settings are reset to factory configuration and receiver performs a cold start on next power
up.
4.1.5.2 Sleep Mode
Sleep mode means a low quiescent (440uA type.) power state, non-volatile RTC, and backup RAM block is
powered on. Other internal blocks like digital baseband and RF are internally powered off. The power supply
input VCC shall be kept active all the time, even during sleep mode.
Entering into sleep mode is sent PMTK command through the communication interface by host side.
Waking up from sleep mode is sent any byte through the communication interface by host side.
4.1.6 VCC_RF
VCC_RF is a 2.8V output for external active antenna, if the external active antenna works at 2.8V voltage supply
domain, the user can use the VCC_RF directly. If the antenna’s power supply is not 2.8V, it should be open. For
passive antenna, VCC_RF should be open.
4.2 UART Interface
SIM68R includes two UART (UART and UART1) interface for serial communication. The UART is as NMEA
output and PMTK command input. The receiver (RXD) and transmitter (TXD) side of every port contains a
16-byte FIFO and has 256 bytes URAM. the baud rates are selectable and ranging from 4.8 to 921.6kbps through
CoreBuilder tool. UART can provide the developers signal or message outputs. UART1 is as RTCM input.
For details about CoreBuilder information, please refer to document [2]
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Table 5: Host port multiplexed function pins
Pin name Pin number UART function
TXD 3 data transmit
RXD 4 data receive
4.3 I2Cinterface
The SCL and SDA are the I2C bus pins, which can be connected to a external I2Cinterface EEPROM up to 1
Mbits for reading and writing data into EEPROM. This can be used to store configurations permanently.
NOTE: The EEPROM can’t be supported currently.
4.4 Timemark Output
The Timemark pin outputs pulse-per-second (1PPS) pulse signal for precise timing purposes. It will come out
after successfully positioning .The Timemark signal can be provided through designated output pin for many
external applications. This pulse is not only limited to be active every second but also allowed to set the required
duration, frequency, and active high/low by programming user-defined settings.
4.5 DET_N
DET_N is an input pin and is used to report whether an external circuit has detected an external antenna or
not .Low level means the antenna has been detected. High level means no external antenna has been detected.
NOTE: The High level for DET_N should be 2.85V CMOS level.
4.6 A-GPS
A-GPS is the meaning of Assisted GPS, which is a system that can under certain conditions improve the startup
performance, or time-to-first-fix (TTFF) of a GPS satellite-based positioning system. SIM68R module supports
EPO file, EASY mode and SBAS/RTCM
4.6.1 EPO
The SIM68R supports the EPO (Extended Prediction Orbit) data service. The EPO data service is supporting
7/14/30-day orbit predictions to customers. It needs occasional download from EPO server. Supply of aiding
information like ephemeris, almanac, rough last position and time and satellite status and an optional time
synchronization signal will reduce time to first fix significantly and improve the acquisition sensitivity.
The user should update the EPO files from the EPO server daily through the internet. Then the EPO data should
send to the SIM68R by the HOST side. SIM68R has the short cold TTFF and warm TTFF, when the A-GPS is
used.
Note: For more information about EPO, please contact SIMCom sales. users can refer to document [4] for more information

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4.6.2 EASY MODE
EASY is the abbreviation of Embedded Assist System, it works as embedded firmware which accelerates TTFF
by predicting satellite navigation messages from received ephemeris.
No additional computing interval for EASY task. EASY is efficiently scheduled and computed in free time of
every second after GPS navigation solution.
EASY function is conceptually designed to automatically engage for predicting after first receiving the broadcast
ephemeris. After a while （generally tens of seconds）, 3-day extensions will be completely generated then all
EASY functions will be maintained at a sleep condition. EASY assistance is going to be engaged when the GPS
requests in new TTFF condition or re-generates again with another new received ephemeris. Meanwhile, TTFF
will be benefited by EASY assistance.
Note: EASY function is default open and can be closed by PMTK command.
4.6.3 SBAS and RTCM
SBAS is the abbreviation of Satellite Based Augmentation System. The SBAS concept is based on the
transmission of differential corrections and integrity messages for navigation satellites that are within sight of a
network of reference stations deployed across an entire continent. SBAS messages are broadcast via geostationary
satellites able to cover vast areas.
Several countries have implemented their own satellite-based augmentation system. Europe has the European
Geostationary Navigation Overlay Service (EGNOS) which covers Western Europe and beyond. The USA has
its Wide Area Augmentation System (WAAS). Japan is covered by its Multi-functional Satellite Augmentation
System (MSAS). India has launched its own SBAS program named GPS and GEO Augmented Navigation
(GAGAN) to cover the Indian subcontinent.
SIM68R module supports SBAS and RTCM, but only one mode can be applied at one time, and SBAS is the
default feature, customers who want to apply RTCM in the design can contact SIMCom sales for supporting
4.7 GNSS Antenna
The SIM68R is designed for use with passive and active antennas.
Table 6: Antenna Specifications
Parameter Specification Passive and active antenna
Frequency range 1574～1606MHz
Polarization RHCP
Gain 20dB<Gain<30dB
Active Antenna Recommendations
Noise Figure <1.5 dB

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4.7.1 Antenna Interface
The SIM68R receives L1 band signals from GNSS and GALILEO satellites at a nominal frequency of 1574～
1606 MHz. The RF signal is connected to the RF_IN pin. And the trace from RF_IN to antenna should be 50Ω
controlled.
To suit the physical design of individual applications the RF interface pad can lead to three alternatives:
zRecommended approach: solderable RF coaxial cable assembly antenna connector, such as HRS’
U.FL-R-SMT(10) connector or I-PEX’s 20279-001E-01 RF connector.
zSMA connector.
4.7.2 GNSS Antenna Choice Consideration
To obtain excellent GNSS receiving performance, a good antenna will always be required. The antenna is the
most critical item for successful GNSS receiving in a weak signal environment. Proper choice and placement of
the antenna will ensure that satellites at all elevations can be seen, and therefore, accurate fix measurements are
obtained.
4.7.2.1 Passive Antenna
Passive antenna contains only the radiating element, e.g. the ceramic patch, the helix structure, and chip
antennas. Sometimes they also contain a passive matching network to match the electrical connection to 50 Ohms
impedance.
The most common antenna type for GNSS applications is the patch antenna. Patch antennas are flat, generally hav
e a ceramic and metal body and are mounted on a metal base plate.
Figure 5 shows a minimal setup for a PVT GNSS receiver with SIM68R module.