u-blox NEO-5 Series, Hardware Integration Manual

Page 1: ...perSense Indoor GPS providing best in class acquisition and tracking sensitivity low power consumption and an innovative jamming resistant RF architecture The compact 16 0 x 12 2 mm form factor of the highly successful NEO 4S is maintained enabling easy migration The NEO 5 series supports passive and active antennas u blox AG Zürcherstrasse 68 8800 Thalwil Switzerland www u blox com Phone 41 44 72...

Page 2: ...x makes no warranties based on the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications and product descriptions at any time without notice u blox reserves all rights to this document and the information contained herein Reproduction use or disclosure to third parties without express permission is strictly prohibited Copyright 2008 u bl...

Page 3: ...ing to the end To help in finding needed information a brief section overview is provided below 1 Hardware Basics This chapter introduces the basics of function and architecture of the NEO 5 modules 2 Design In This chapter provides the Design In information necessary for a successful design 3 Product Handling This chapter defines packaging handling shipment storage and soldering 4 Product Testing...

Page 4: ...ll find the contact details at the end of the document By Phone If an email contact is not the right choice to solve your problem or does not clearly answer your questions call the nearest Technical Support office for assistance You will find the contact details at the end of the document Helpful Information when Contacting Technical Support When contacting Technical Support please have the follow...

Page 5: ...11 2 2 1 EXTINT External Interrupt Pin 11 2 2 2 System Monitoring 11 2 3 Interfaces 11 2 3 1 Serial 11 2 3 2 USB 11 2 3 3 Display Data Channel DDC 13 2 3 4 Synchronous Peripheral Interface SPI 13 2 4 I O Pins 13 2 4 1 EXTINT0 13 2 4 2 Configuration Pins CFG_COM0 CFG_GPS0 13 2 5 Design In 14 2 5 1 Schematic Design In Checklist for u blox 5 14 2 5 2 NEO 5 Design 14 2 5 3 Design for NEO 5M NEO 5Q 16 ...

Page 6: ...essing 30 3 3 1 Moisture Preconditioning 30 3 3 2 Soldering Paste 30 3 3 3 Reflow Soldering 31 3 3 4 Optical Inspection 32 3 3 5 Cleaning 33 3 3 6 Repeated Reflow Soldering 33 3 3 7 Wave Soldering 33 3 3 8 Hand Soldering 33 3 3 9 Rework 33 3 3 10 Conformal Coating 34 3 3 11 Casting 34 3 3 12 Grounding Metal Covers 34 3 3 13 Use of Ultrasonic Processes 34 4 Product Testing 35 4 1 u blox In Series P...

Page 7: ...pol 41 B 5 Helix or Patch which selection is best 41 B 6 Antenna Matching 42 B 7 Antenna Placement 43 C Interference Issues 44 C 1 Sources of Noise 44 C 2 Eliminating Digital Noise Sources 45 C 2 1 Power and Ground Planes 45 C 2 2 High Speed Signal Lines 46 C 2 3 Decoupling Capacitors 46 C 3 Shielding 48 C 3 1 Feed through Capacitors 48 C 3 2 Shielding Sets of Sub System Assembly 50 D Lists 51 D 1...

Page 8: ...ithin a single component NEO 5 modules maintain the compact 17 0 x 22 4 mm form factor of the highly successful NEO 4S predecessor The NEO 5 modules have been designed with backwards compatibility in mind enabling ease of upgrade and reducing engineering and design costs Their small size makes NEO 5 modules the ideal GPS solution for applications with stringent space requirements The packaging mak...

Page 9: ...ntegrated Low Noise Amplifier LNA the SAW bandpass filter the u blox 5 RF IC and the TCXO or XTO crystal The Baseband section contains the digital circuitry comprised of the u blox 5 Baseband processor the RTC crystal and additional elements such as the optional FLASH EPROM for enhanced programmability and flexibility RF Front End with Integrated LNA Baseband Processor Power Management TCXO or XTA...

Page 10: ...tude especially if low power operation modes are enabled It is important that the system power supply circuitry is able to support the peak power see datasheet for specification for a short time In order to define a battery capacity for specific applications the sustained power figure shall be used 2 1 1 2 V_BCKP Backup Battery In case of a power failure on pin VCC the real time clock and backup R...

Page 11: ...nd GALILEO Receiver provides System Monitoring functions that allow the operation of the embedded processor and associated peripherals to be supervised These System Monitoring functions are being output as part of the UBX protocol class MON Please refer to the u blox 5 Protocol Specification 3 For more information on UBX messages serial interfaces for design analysis and individual system monitori...

Page 12: ...modules Check the CFG_COM0 configuration pin to select between Self and Bus Powered modes Note that BUS Powered mode is not at this time supported For more information on configuration see the NEO 5 Data Sheet 2 Bus Powered Self Powered NEO 5Q P NEO 5M P Supported P Planned availability Q1 09 Table 2 USB availability on NEO 5 modules Module VDD_USB LDO VDD_USB R4 USB_DP USB_DM R5 C24 C23 D2 VBUS D...

Page 13: ...rted at this time 2 4 I O Pins 2 4 1 EXTINT0 EXTINT0 is an external interrupt pin with fixed input voltage thresholds independent of VCC see the NEO 5 Data Sheet 2 Leave open if unused 2 4 2 Configuration Pins CFG_COM0 CFG_GPS0 NEO 5Q and NEO 5M provide one or two pins for boot time configuration These pins become effective immediately after start up Once the module has started the configuration s...

Page 14: ...en choose NEO 5Q Check Power Supply Requirements and Schematic Is the power supply within the specified range Is the voltage VDDUSB within the specified range Compare the peak current consumption of NEO 5 with the specification of your power supply GPS receivers require a stable power supply avoid ripple on VCC 50mVpp Backup Battery For achieving a minimal Time To First Fix TTFF after a power down...

Page 15: ... u blox recommends using an inductor from Coilcraft 0402CS 36NX Alternative parts can be used if the inductor s resonant frequency matches the GPS frequency of 1575 4MHz Low Noise Amplifier Active Antenna RF_IN VCC_RF GND GND Figure 5 Recommended wiring for active antennas For optimal performance it is important to place the inductor as close to the microstrip as possible Figure 6 illustrates the ...

Page 16: ... a NEO 5 module Vcc Micro Processor serial Passive Antenna Backup Battery NEO 5 Top View 2 3 4 5 6 8 10 12 24 22 21 20 19 17 15 13 23 GND Reserved SS_N NC TIMEPULSE EXTINT0 USB_DM USB_DP VDDUSB Reserved VCC_RF GND GND RF_IN GND VCC V_BCKP RxD1 TxD1 SCL2 SDA2 SCS1_N NC CFG_GPS0 SCK NC MISO NC MOSI CFG_COM0 14 16 11 9 7 1 18 USB port optional Micro Processor USB Figure 7 Passive Antenna Design for N...

Page 17: ...antenna has to be routed on the PCB Use a controlled impedance of 50 Ohm to connect RF_IN to the antenna or the antenna connector 12 GND I Ground See pin 10 13 GND I Ground See pin 10 14 MOSI CFG_COM0 O SPI MOSI CFG_COM0 NEO 5Q Leave open if not used See Section 2 3 2 NEO 5M Leave open Connect to GND to use USB in Self Powered mode 15 MISO NC I SPI MISO Not Connected NEO 5Q SPI MISO Leave open if ...

Page 18: ...or improved shielding add as many vias as possible around the micro strip around the serial communication lines underneath the GPS module etc Calculation of the micro strip Section 2 7 5 The micro strip must be 50 Ohms and be routed in a section of the PCB where minimal interference from noise sources can be expected In case of a multi layer PCB use the thickness of the dielectric between the sign...

Page 19: ...2 Paste Mask Figure 9 shows the recommended positioning of the Paste Mask the Copper and Solder masks as well as the step stencil These are recommendations only and not specifications Note that the Copper and Solder masks have the same size and position To improve the wetting of the half vias reduce the amount of solder paste under the module and increase the volume outside of the module by defini...

Page 20: ...and solder paste volumes must be adapted to the specific production processes e g soldering etc of the customer 2 7 3 Placement A very important factor in achieving maximum GPS and GALILEO performance is the placement of the receiver on the PCB The connection to the antenna must be as short as possible to avoid jamming into the very sensitive RF section Make sure that RF critical circuits are clea...

Page 21: ...8 7 6 5 4 3 2 1 13 30 Digital Part RF Part Figure 10 Placement 2 7 4 Antenna Connection and Grounding Plane Design u blox 5 modules can be connected to passive patch or active antennas The RF connection is on the PCB and connects the RF_IN pin with the antenna feed point or the signal pin of the connector respectively Figure 11 illustrates connection to a typical five pin RF connector One can see ...

Page 22: ...he whole layer stack below the RF connection should be kept free of digital lines This is because even solid ground planes provide only limited isolation The impedance of the antenna connection has to match the 50 Ohm impedance of the receiver To achieve an impedance of 50 Ohms the width W of the micro strip has to be chosen depending on the dielectric thickness H the dielectric constant εr of the...

Page 23: ...of the micro strip line to the ground plane on the bottom side of the receiver is very small some 100 μm and has huge tolerances up to 100 Therefore the impedance of this part of the trace cannot be controlled Use as many vias as possible to connect the ground planes In order to avoid reliability hazards the area on the PCB under the receiver should be entirely covered with solder mask Vias should...

Page 24: ... blox 5 modules receive L1 band signals from GPS and GALILEO satellites at a nominal frequency of 1575 42 MHz The RF signal is connected to the RF_IN pin u blox 5 modules can be connected to passive or active antennas For u blox 5 receivers the total preamplifier gain minus cable and interconnect losses must not exceed 50 dB Total noise figure should be below 3 dB 2 8 1 Passive Antenna A design us...

Page 25: ...h antenna bias supply AND there is a chance of a passive antenna being connected to the design consider a short circuit protection All u blox 5 receivers have a built in LNA required for passive antennas 2 8 2 Active Antenna NEO 5 modules do not provide the antenna bias voltage for active antennas at the RF_IN pin See Section 2 5 2 for more information 2 8 3 Active Antenna Supervisor NEO 5 modules...

Page 26: ...aging NEO 5 modules are delivered as hermetically sealed reeled tapes in order to enable efficient production production lot set up and tear down Figure 15 Reeled u blox 5 Modules 3 1 1 Reels NEO 5 modules for GPS and GALILEO are deliverable in quantities of 250pcs on a reel The dimensions of the reel are shown in Figure 16 Figure 16 Dimension of reel for 250 pieces dimensions unless otherwise spe...

Page 27: ...e shipped in Tape and Reel These components contain highly sensitive electronic circuitry Handling the NEO 5 modules without proper ESD protection may destroy or damage them permanently According to JEDEC ISP NEO 5 modules are moisture sensitive devices Appropriate handling instructions and precautions are summarized in Sections 3 2 2 to 3 2 5 Read them carefully to prevent permanent damages due t...

Page 28: ...instructions 3 2 3 Storage Shelf life in sealed bag is 12 months at 40 C and 90 relative humidity 3 2 4 Handling A humidity indicator card and a desiccant bag to absorb humidity are enclosed in the sealed package The parts are shipped on tape and reel in a hermetically sealed package If no moisture has been absorbed the three fields in the humidity indicator card indicate blue color 01 01 2008 ...

Page 29: ...conditions 30 C 60 relative humidity the parts must be processed and soldered within this specified period of time Once the sealed package of the reel is opened and the parts exposed to humidity they need to be processed within 72 hours precisely three days in a reflow soldering process If this time is exceeded or the sticker in the sealed package indicates that the goods have been exposed to mois...

Page 30: ...ag and use a vacuum hot barrier sealing machine for sealing if not processed within specified floor time Storage in a nitrogen cabinet or dry box is also a possible approach to prevent moisture intake Do not attempt to bake the NEO 5 modules contained in tape and rolled up in reels If necessary bake the NEO 5 modules quickly at 125 C for 48 hours remove them from the belt and place them individual...

Page 31: ...rformed excessively fine balls and large balls will be generated in clusters End Temperature 150 200 C If the temperature is too low non melting tends to be caused in areas containing large heat capacity Heating Reflow Phase The temperature rises above the liquidus temperature of 216 221 C Avoid a sudden rise in temperature as the slump of the paste could become worse Limit time above 220 C liquid...

Page 32: ... C Figure 20 Recommended soldering profile When soldering leadfree u blox 5 modules in a leaded process check the following temperatures o PB Technology Soaktime 40 80sec o Time above Liquidus 40 90 sec o Peak temperature 225 235 C NEO 5 modules must not be soldered with a damp heat process 3 3 4 Optical Inspection After soldering the NEO 5 module consider an optical inspection step to check wheth...

Page 33: ...ng step after the soldering 3 3 6 Repeated Reflow Soldering Only a single reflow soldering process is encouraged for boards with a NEO 5 module populated on it The reason for this is the risk of the module falling off due to high weight in relation to the adhesive properties of the solder 3 3 7 Wave Soldering Base boards with combined through hole technology THT components and surface mount techno...

Page 34: ...M is strongly advised to qualify such processes in combination with the NEO 5 module before implementing this in the production Casting will void the warranty 3 3 12 Grounding Metal Covers Attempts to improve grounding by soldering ground cables wick or other forms of metal strips directly onto the EMI covers is done at the customer s own risk The numerous ground pins should be sufficient to provi...

Page 35: ...uipment which delivers a detailed test report for each unit The following measurements are done Digital self test Software Download verification of FLASH firmware etc Measurement of voltages and currents Measurement of RF characteristics e g C No Figure 21 Automatic Test Equipment for Module Tests 4 2 Test Parameters for OEM Manufacturer Because of the testing done by u blox with 100 coverage it i...

Page 36: ...annel GPS simulator to the OEM product 2 Choose the power level in a way that the Golden Device would report a C No ratio of 38 40 dBHz 3 Power up the DUT Device Under Test and allow enough time for the acquisition 4 Read the C No value from the NMEA GSV or the UBX NAV SVINFO message e g with u center AE 5 Compare the results to a Golden Device or a u blox 5 Evaluation Kit 4 3 2 Go No go tests for...

Page 37: ...EXTINT0 NC EXTINT0 NC 5 USB_DM NC USB_DM NC 6 USB_DP NC USB_DP NC 7 VDDUSB Connected to GND or VDD_USB VDDUSB Connected to GND or VDD_USB Do not leave open VDD_USB is 3 3V regulated power supply from VBUS 8 Reserved NC Reserved NC Pins 8 and 9 must be connected 9 VCC_RF VCC 0 1V VCC_RF VCC 0 1V No difference 10 GND GND GND GND No difference 11 RF_IN RF_IN RF_IN RF_IN No difference 12 GND GND GND G...

Page 38: ... only loaded with air it will be comparatively large high dielectric constant ceramics result in a much smaller form factor The smaller the dimensions of the antenna the more performance critical tight manufacturing tolerances become Furthermore a smaller antenna will present a smaller aperture to collect the signal energy from sky resulting in a lower overall gain of the antenna This is the resul...

Page 39: ...enna is always advisable if the RF cable length between receiver and antenna exceeds approximately 10 cm Care should be taken that the gain of the LNA inside the antenna does not lead to an overload condition at the receiver For receivers that also work with passive antennas an antenna LNA gain of 15 dB is usually sufficient even for cable lengths up to 5 m There s no need for the antenna LNA gain...

Page 40: ... the correct dimensions for the size of the ground plane can serve as a useful compromise between maximum gain and reasonable polarization loss Figure 26 Typical Gain and Axial Ratio of a Patch antenna with respect to ground plane size MuRata Inc A good allowance for ground plane size is typically in the area of 50 to 70 mm2 This number is largely independent of the size of the patch itself when c...

Page 41: ...size and shape of the ground plane As with patch antennas filling the antenna with a material with a high dielectric constant can reduce the size of helix antennas Sizes in the order of 18 mm length and 10 mm diameter are being offered on the market Again antenna gain will decrease with decreased size B 5 Helix or Patch which selection is best For practical applications the possibilities of integr...

Page 42: ...o analyze effects like this one would normally employ electrical field simulations which will result in exact representation of the electric fields in the near field of the antenna Furthermore these distortions of the near field will also show their effect in the far field changing the radiation pattern of the antenna Unfortunately there is no simple formula to calculate the frequency shift of a g...

Page 43: ...ing a direct line of sight with as many visible satellites as possible 1st Choice Placement 2nd Choice Placement Recommended Antenna positions Performance may be degraded If recommended placements are not available these may also viable Note Window and roof reduce GPS signal and obstruct sky view 2 Note There may be multipath signals and a obstructed sky view Note Fiberglass airfoil attenuates the...

Page 44: ...ax 30 dBm at 1710 MHz in close proximity to the GPS GALILEO antenna When integrating GPS GALILEO with other RF transmitters special care is necessary If the particular application requires integration of the antenna with other digital systems one should make sure that jamming signal levels are kept to an absolute minimum Even harmonics of a CPU clock can reach as high as 1 5 GHz and still exceed t...

Page 45: ...neral hints on how to decrease the level of noise emitted from digital circuit board that are potentially in close proximity to the GPS receiver or the antenna C 2 1 Power and Ground Planes Use solid planes for power and ground interconnect This will typically result in a PCB with at least four layers but will also result in a much lower radiation Solid ground planes ensure that there is a defined...

Page 46: ...small capacitance types reduce high frequency emissions Large size high capacitance types stabilize low frequency variations It s preferred to have a large number of small value capacitors in parallel rather than having a small number of large value capacitors Every capacitor has an internal inductance in series with the specified capacitance In addition to resonance the capacitor will also behave...

Page 47: ...igital part Tantalum capacitors show good thermal stability however their high ESR equivalent series resistance limits the usable frequency range to some 100 kHz Figure 33 Temperature dependency of COG NPO dielectric AVX Figure 34 Temperature dependency of X7R dielectric AVX Figure 35 Temperature dependency of Y5V dielectric AVX ...

Page 48: ...metal box will terminate all electrical fields on its surface In practice we have the problem that we need to route some signals from inside to outside of this box Signal Layers SupplyGroundLayer noisy Shield free of supplycurrents Signal line leavingbox FeedthroughCapacitor Figure 36 Ideal shielding The proposed setup for such a system is shown in Figure 36 A feed through capacitor removes all hi...

Page 49: ...oint that the capacitor is connected to is not ideal meaning the ground connection or plane has a finite resistance noise will be injected into the ground net Therefore one should try to place any feed trough capacitor far away from the most noise sensitive parts of the circuit To emphasize this once again one should ensure a very good ground connection for the feed through capacitor If there is n...

Page 50: ...ty ground connection between the two shields But now it might be difficult to control the path of the ground return currents to the power supply since the shield is probably connected to the supply ground at more than one location The preferred solution is shown in Figure 39 Again it is important to have a good i e low inductance interconnection between the outer shield and the shielding ground of...

Page 51: ...MSD Label See Section 3 1 for baking instructions 28 Figure 19 Humidity Indicator Card good condition 29 Figure 20 Recommended soldering profile 32 Figure 21 Automatic Test Equipment for Module Tests 35 Figure 22 1 channel GPS simulator 36 Figure 23 Patch Antennas EMTAC Technology Corp 38 Figure 24 Quadrifilar Helix Antenna Sarantel Ltd 38 Figure 25 Typical Radiation Pattern of a Patch Antenna MuR...

Page 52: ...cement 43 E Glossary API Application Programming Interface BBR Battery backup RAM ECEF Earth Centered Earth Fixed ESD Electro Static Discharge HAE Height Above WGS84 Ellipsoid LNA Low Noise Amplifier LOS Line of sight NMEA 0183 ASCII based standard data communication protocol used by GPS receivers PUBX u blox proprietary extension to the NMEA protocol PVT Position Velocity Time SA Selective Availa...

Page 53: ... A2 u blox proprietary Page 53 your position is our focus Related Documents 1 GNSS Compendium Doc No GPS X 02007 2 NEO 5 Data Sheet Doc No GPS G4 MS5 07025 3 u blox 5 Protocol Specification Doc No GPS G5 X 07063 All these documents are available on our homepage http www u blox com ...

Page 54: ...il info u blox com Technical Support Phone 41 44 722 74 74 E mail support u blox com Asia Australia Pacific u blox Singapore Pte Ltd 435 Orchard Road 17 01 Wisma Atria Singapore 238877 Phone 65 6734 3811 Fax 65 6736 1533 E mail info_ap u blox com Support support_ap u blox com Regional Office China Room 716 718 No 65 Fuxing Road Beijing 100036 China Phone 86 10 68 133 545 Fax 86 10 68 217 890 E mai...