Quectel LC79D Hardware Design Download

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LC79D

Hardware Design

GNSS Module Series

Rev. LC79D_Hardware_Design_V1.0

Date: 2019-11-14

Status: Released

www.quectel.com

Summary of Contents for LC79D

Page 1: ...LC79D Hardware Design GNSS Module Series Rev LC79D_Hardware_Design_V1 0 Date 2019 11 14 Status Released www quectel com ...

Page 2: ...HE INFORMATION PROVIDED IS BASED UPON CUSTOMERS REQUIREMENTS QUECTEL MAKES EVERY EFFORT TO ENSURE THE QUALITY OF THE INFORMATION IT MAKES AVAILABLE QUECTEL DOES NOT MAKE ANY WARRANTY AS TO THE INFORMATION CONTAINED HEREIN AND DOES NOT ACCEPT ANY LIABILITY FOR ANY INJURY LOSS OR DAMAGE OF ANY KIND INCURRED BY USE OF OR RELIANCE UPON THE INFORMATION ALL INFORMATION SUPPLIED HEREIN IS SUBJECT TO CHAN...

Page 3: ...GNSS Module Series LC79D Hardware Design LC79D_Hardware_Design 2 39 About the Document History Revision Date Author Description 1 0 2019 11 14 Brooke WANG Phil GAO Initial ...

Page 4: ...2 Pin Description 15 3 3 Power Supply 18 3 4 Operation Modes 19 3 4 1 Full on Mode 19 3 4 2 Sleep Mode 20 3 4 3 Standby Mode 20 3 5 UART Interface 21 3 6 SPI Interface 22 3 7 I2C Interface 23 3 8 Boot Interface 24 4 Antenna Interfaces 26 4 1 Antenna Specifications 26 4 2 Recommended Antenna Reference Designs 27 4 2 1 Antenna Selection Guide 27 4 2 1 Active Antenna Reference Design 27 4 2 2 Passive...

Page 5: ...esign 4 42 6 1 Mechanical Dimensions of the Module 33 6 2 Recommended Footprint 35 6 3 Top and Bottom Views 36 7 Storage Manufacturing and Packaging 37 7 1 Storage 37 7 2 Manufacturing and Soldering 38 7 3 Tape and Reel Packaging 39 8 Appendix A References 41 ...

Page 6: ...S 12 TABLE 5 I O PARAMETERS DEFINITION 15 TABLE 6 PIN DESCRIPTION 15 TABLE 7 DEFAULT CONFIGURATIONS 19 TABLE 8 WORKING MODES 24 TABLE 9 RECOMMENDED ANTENNA SPECIFICATIONS 26 TABLE 10 ABSOLUTE MAXIMUM RATINGS 30 TABLE 11 POWER SUPPLY RATINGS 31 TABLE 12 CURRENT CONSUMPTION 31 TABLE 13 RECOMMENDED THERMAL PROFILE PARAMETERS 38 TABLE 14 PACKAGING SPECIFICATIONS 40 TABLE 15 RELATED DOCUMENTS 41 TABLE ...

Page 7: ...GURE 7 REFERENCE DESIGN OF SPI INTERFACE 23 FIGURE 8 BOOT PIN STATE NORMAL WORKING MODE 24 FIGURE 9 BOOT PIN CONTROL SEQUENCE HOST MODE 24 FIGURE 10 REFERENCE DESIGN FOR ACTIVE ANTENNA 28 FIGURE 11 REFERENCE DESIGN FOR PASSIVE ANTENNA 28 FIGURE 12 TOP AND SIDE DIMENSIONS 33 FIGURE 13 BOTTOM DIMENSIONS 34 FIGURE 14 RECOMMENDED FOOTPRINT 35 FIGURE 15 TOP VIEW OF THE MODULE 36 FIGURE 16 BOTTOM VIEW O...

Page 8: ...ify users and operating personnel of the following safety information by incorporating these guidelines into all manuals supplied with the product If not so Quectel assumes no liability for any user s failure to observe these precautions Ensure that the use of the product meets the national safety and environmental regulations and is allowed in the country and in the environment required Keep away...

Page 9: ...trial level of sensitivity and accuracy with the lowest power consumption in an ultra small footprint LC79D is a SMD type module with an ultra compact form factor of 10 1mm 9 7mm 2 4mm It can be embedded into terminals through its 18 LCC pins and 10 LGA pins This document provides necessary hardware interfaces for connection with the motherboard of terminals The module is fully compliant with EU R...

Page 10: ...ing Table 2 Key Differences between LC79D A and LC79D B 2 2 1 UDR Technology UDR refers to the capability of a GNSS receiver to continuously navigate on a vehicle when there are insufficient GNSS satellite signals available To realize this function the receiver uses the information provided by external sensors concerning the state of the vehicle to propagate the navigation solution With this combi...

Page 11: ...eiDou GLONASS Galileo QZSS IRNSS Acquisition 47mA Tracking 43mA Sleep mode 200μA Standby mode 17μA Sensitivity GPS GLONASS Acquisition 147dBm Reacquisition 158dBm Tracking 163dBm Sensitivity IRNSS only Acquisition 144dBm Reacquisition 151dBm Tracking 155dBm TTFF without AGNSS Cold start 34s Warm start 30s Hot start 2s TTFF with AGNSS Cold Start 5s Horizontal Position Accuracy Autonomous 1 2m CEP 1...

Page 12: ...nce in challenging environments with a cellular module transmitting B13 at the same time for example and provide LC79D with better performance in anti jamming UART Interface One UART interface for LC79D A Support baud rate from 115200bps to 921600bps 115200bps by default UART port is used for NMEA output and firmware upgrade SPI Interface One SPI interface for LC79D B Operate as a slave Fixed data...

Page 13: ...5MB ROM 1MB 32 768K LC79D RTC VCC VCC_RF CPU ARM Cortex M0 low power L5 L1 LNA DIP LNA XTAL LC79D A only Figure 1 Block Diagram 2 5 Evaluation Board In order to facilitate application development with LC79D Quectel supplies an evaluation board LC79D EVB with a Micro USB cable an active antenna and other peripherals to test the module For more details please refer to document 2 and document 3 2 6 S...

Page 14: ...GNSS Module Series LC79D Hardware Design LC79D_Hardware_Design 13 42 Please refer to document 1 for more details NOTE ...

Page 15: ...motherboard of any terminal 3 1 Pin Assignment TXD SPI_CLK GND 24 BOOT RESERVED RESERVED GND RXD SPI_CS 1PPS NSTANDBY RESERVED VCC RESERVED RESERVED I2C_SCL INT I2C_SDA RESERVED VCC_RF RF_IN GND LNA_EN GND RT S SPI_MISO REQ RD Y RESERVED AP_REQ CT S SPI_MOSI 9 1 2 3 4 5 6 7 8 10 18 17 16 15 14 13 12 11 25 26 27 28 19 20 21 22 23 LC79D Top View GND POWER RESERVED GPIO BOOT ANT Figure 2 Pin Assignme...

Page 16: ...log Input AO Analog Output DI Digital Input DO Digital Output IO Bidirectional OD Open Drain PI Power Input PO Power Output Power Supply Pin Name Pin No I O Description DC Characteristics Comment VCC 8 PI Main power supply Vmax 1 9V Vmin 1 7V Vnom 1 8V Ensure the load current not less than 100mA VCC_RF 14 PO Power supply for external RF components VCC_RF VCC Vmax 1 9V Vmin 1 7V Vnom 1 8V Typically...

Page 17: ...Receive data SPI chip select RTS SPI_MISO 22 DO Request to send SPI master in salve out CTS SPI_MOSI 23 DI Clear to send SPI master out slave in RF Interface Pin Name Pin No I O Description DC Characteristics Comment RF_IN 11 AI RF signal input 50Ω characteristic impedance I2C Interface Pin Name Pin No I O Description DC Characteristics Comment I2C_SDA 16 OD I2C serial data VILmax 0 35 VCC VIHmin ...

Page 18: ...keep this pin open GND 1 10 12 28 GND All GND pins should be connected to ground RESERVED 6 7 9 15 24 26 27 RESERVED Keep them open Host Mode Interfaces Pin Name Pin No I O Description DC Characteristics Comment REQ 21 DO Data availability indication used to indicate whether there is data available for reading VOLmax 0 4V VOHmin VCC 0 45V VOHnom 1 8V High level there is data available for reading ...

Page 19: ...t an LDO with minimum output current of 100mA as the power supply and add a decoupling capacitor combination 10μF and 100nF as well as a TVS near the VCC pin It is strongly discouraged to use a pulse frequency modulation regulator for power supply PMU VCC 10μF 100nF Module TVS ESD5651N Figure 3 VCC Input Reference Circuit ready for communication with the AP when AP_REQ is driven high Low level the...

Page 20: ... as code phase of satellite signals When the acquisition is completed it will automatically switch to tracking mode In tracking mode the module tracks satellites and demodulates the navigation data from specific satellites When the module is powered on it will enter full on mode automatically and follow the default configurations as below Table 7 Default Configurations GGA RMC GSA and GSV are the ...

Page 21: ... Driving AP_REQ high will wake up the module from sleep mode and then the GNSS engine can be started with PQSTARTGNSS command When sleep mode is used please keep REQ pin at low level For the reference design please refer to documents 3 3 4 3 Standby Mode In standby mode only RTC domain is active and other parts are inactive Driving NSTANDBY low and keeping it at low level will set the module into ...

Page 22: ...module provides one UART interface The following are the features of the UART UART is used for NMEA output and firmware upgrade UART supports baud rates 115200bps 230400bps 460800bps 921600bps The default baud rate is 115200bps 8 bits no parity bit 1 stop bit The UART interface features 1 8V power domain A voltage level translator should be used if customers application is equipped with a 3 3V UAR...

Page 23: ... when the firmware bootloader needs to be updated it is necessary to use a four wire UART TXD RXD CTS and RTS in host mode for upgrading 2 represents the test points of UART interface 3 6 SPI Interface LC79D B provides one SPI interface for connection with an external android device The following are the features of the SPI interface Operate as a slave Slave interface can operate in full duplex at...

Page 24: ...in at high level for 100ms during the startup of LC79D B module For more details about the control circuit please refer to documents 3 3 7 I2C Interface LC79D module provides one I2C interface which provides features as listed below Support Standard mode 100kbps Fast mode 400kbps Fast mode Plus 1Mbps and High Speed mode 3 4Mbps Single master capability no multimaster or slave capability Support fo...

Page 25: ... 8 Working Modes VCC BOOT 11s Figure 8 BOOT Pin State Normal Working Mode VCC BOOT 100ms 0ms Keep Floating Figure 9 BOOT Pin Control Sequence Host Mode Voltage Level Working Mode Comment Floating Normal While keeping the pin floating during startup LC79D module will enter normal working mode High Host While keeping the pin at high level for about 100ms during startup LC79D module will enter host m...

Page 26: ...GNSS Module Series LC79D Hardware Design LC79D_Hardware_Design 25 42 1 LC79D B must work in host mode 2 For more details about the reference design of BOOT interface please refer to documents 3 NOTES ...

Page 27: ...a dedicated passive or active dual band L1 L5 GNSS antenna that supports GPS BeiDou GLONASS Galileo IRNSS and QZSS satellite signals The recommended antenna specifications are given in the following table Table 9 Recommended Antenna Specifications The total gain of the whole antenna is the internal LNA gain minus total insertion loss of cables and components inside the antenna Antenna Type Specifi...

Page 28: ...mong all the quantities Power of GNSS signal means GNSS signal level and in practical environment the signal level at the surface of earth is about 130dBm Thermal Noise is 174dBm Hz at 290K To improve CNR of GNSS signal a LNA could be added to reduce System NF For System NF it is expressed by formula as NF 10 log F dB And F denotes noise factor of receiver system F F1 F2 1 G1 F3 1 G1 G2 F1 denotes...

Page 29: ...1 is 0Ω C1 is 100pF while C2 and C3 are not mounted The inductor L1 is used to prevent the RF signal from leaking into the VCC_RF and route the bias supply to the active antenna The recommended value of L1 is no less than 68nH R2 can protect the whole circuit in case the active antenna is short circuited to ground 4 2 2 Passive Antenna Reference Design The following figure is a typical reference d...

Page 30: ...are_Design 29 42 C1 R1 C2 are reserved matching circuits for antenna impedance modification By default R1 is 0Ω while C1 and C2 are not mounted The impedance of RF trace should be controlled as 50Ω and the trace length should be kept as short as possible ...

Page 31: ...e 10 Absolute Maximum Ratings Stressing the device beyond the Absolute Maximum Ratings may cause permanent damage The product is not protected against over voltage or reversed voltage Thus it is necessary to utilize appropriate protection diodes to keep voltage spikes between the minimum and maximum values given in table above Parameter Min Max Unit Power Supply Voltage VCC 0 2 2 07 V Input Voltag...

Page 32: ...cautions should be emphasized Proper ESD handling and packaging procedures must be applied throughout processing handling and operation of any application that incorporates the module Please note that the following measures are beneficial to ESD protection when LC79D module is handled Parameter Description Operating Conditions Min Typ Max Unit VCC Supply voltage The actual input voltages must stay...

Page 33: ... between the local GND and the PCB GND When mounting the module onto a motherboard please make sure the GND is connected first and then the RF_IN pad Do not contact any charged capacitors or materials which may easily generate or store charges such as patch antenna coaxial cable soldering iron etc when handling the RF_IN pad Be sure to use an ESD safe soldering iron tip when soldering the RF_IN pi...

Page 34: ...pter describes the mechanical dimensions of the module All dimensions are measured in millimeter mm and the dimensional tolerances are 0 05mm unless otherwise specified 6 1 Mechanical Dimensions of the Module 10 10 0 15 9 70 0 15 8 80 0 10 9 35 0 10 1 00 0 10 2 40 0 20 Figure 12 Top and Side Dimensions ...

Page 35: ...GNSS Module Series LC79D Hardware Design LC79D_Hardware_Design 34 42 Figure 13 Bottom Dimensions ...

Page 36: ...e_Design 35 42 6 2 Recommended Footprint Figure 14 Recommended Footprint For easy maintenance of this module and accessing to these pads it is recommended to keep a distance of no less than 3mm between the module and other components on a motherboard NOTE ...

Page 37: ...sign 36 42 6 3 Top and Bottom Views 1 18 10 9 Figure 15 Top View of the Module 18 1 9 10 23 19 28 24 Figure 16 Bottom View of the Module These are renderings of LC79D module For authentic appearance please refer to the module that you receive from Quectel NOTE ...

Page 38: ... the factory environment of 30ºC 60 RH Stored at 10 RH 3 Devices require baking before mounting if any circumstance below occurs When the ambient temperature is 23º C 5º C and the humidity indication card shows the humidity is 10 before opening the vacuum sealed bag Device mounting cannot be finished within 168 hours at factory conditions of 30ºC 60 4 If baking is required devices may be baked for...

Page 39: ... the peak reflow temperature is 238 245º C and the absolute maximum reflow temperature is 245º C To avoid damage to the module caused by repeated heating it is strongly recommended that the module should be mounted after reflow soldering for the other side of PCB has been completed The recommended reflow soldering thermal profile lead free reflow soldering and related parameters are shown below Te...

Page 40: ...n for the module is made of Cupro Nickel base material It is tested that after 12 hours Neutral Salt Spray test the laser engraved label information on the shielding can is still clearly identifiable and the QR code is still readable although white rust may be found 7 3 Tape and Reel Packaging LC79D is packaged in tape and reel carriers One reel is 8 64m long and contains 500 modules Reflow Zone M...

Page 41: ... 0 15 10 10 à0 15 3 00 à0 15 10 10 0 15 11 10 0 15 11 10 0 15 Unit mm Quantity per reel 500pcs Length per reel 8 64m 330 28 5 13 100 24 5 Out direction Figure 18 Tape and Reel Specifications Table 14 Packaging Specifications Model Name MOQ for MP Minimum Package 500pcs Minimum Package 4 2000pcs LC79D 500pcs Size 370mm 350mm 56mm N W 0 65kg G W 0 86kg Size 380mm 250mm 365mm N W 2 6kg G W 3 44kg ...

Page 42: ...79D Reference Design 5 Quectel_RF_Layout_Application_Note RF Layout Guide 6 Quectel_Module_Secondary_SMT_User_Guide Module Secondary SMT User Guide Table 16 Terms and Abbreviations Abbreviation Description AGNSS Assisted Global Positioning System CEP Circular Error Probable CNR Carrier to Noise Ratio DMA Direct Memory Access ESD Electrostatic Discharge GPS Global Positioning System GNSS Global Nav...

Page 43: ...stem RHCP Right Hand Circular Polarization SAW Surface Acoustic Wave TTFF Time to First Fix UART Universal Asynchronous Receiver Transmitter Vmax Maximum Voltage Value Vnom Nominal 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 Va...

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