GPS receiver GNS302uLP Datasheet preliminary specification 1 INTRODUCTION GNS302uLP is a complete GPS receiver that is optimized for very low power consumption. Thanks to an advanced dynamic power management technology, the current is reduced to a minimum of ~7 mA (<25mW). Average power savings in comparison with common low power GPS modules are 60%. Unlike other concepts that use trickle operation modes with reduced update rates of the position, GNS302uLP works at full 1-per-second position update rate. Best power savings can be achieved in typical outdoor scenarios with wide view angles to the sky. GNS 302uLP allows long term tracking in small applications like fitness wearables, pet tracking and camera applications. Very low power requirements and internal voltage regulator makes it easy to run the receiver with various power supplies and allows direct connection to LiIon batteries. For high accuracy and additional SBAS operation, the GNS302uLP can be switched to continous high activity power mode by software command. GNS 302uLP utilizes a tiny chip antenna to realize high sensitivity with very small space requirements. If radiation pattern and best antenna performance is a main requirement, GNS also offers a patch antenna version (GNS601uLP). Its attractive price and ready-to run configuration with integrated antenna solution reduces time-tomarket to a minimum. First Fixes after just a few seconds are achieved with the help of A-GPS using EPOTM (Extended Prediction Orbit) and the EASYTM self generated orbit prediction algorithm. EASYTM (Embedded Assist System) does not require any resources from the host and no data from the network. 1 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification AlwaysLocateTM power management feature can be activated to further lower the power requirements at lower update rates. It adaptively adjusts power consumption depending on the environment and motion conditions, in order to achive a balance between fix rate, power consumption and position accuracy. GNS302uLP offers the industry's highest level of navigation sensitivity up to -165dBm1. It has superior dynamic performance at high velocity and provides effective protection against interference signals using MTAICTM ( Multi-tone active interference canceller). Up to 12 independent channel interference continious wave jammers <-80dBm can be eliminated or reduced. The embedded logger function LOCUS with a 16-hrs (8000 samples) on chip memory makes this GPS module a complete track logger for many applications. In professional timing applications the outstanding high accuracy PPS (pulse per second) hardware pin is used for synchronization to GPS second. Typical accuracy is 10ns RMS. Features 1 Ultra low power technology at full tracking output rate 66 acquisition-/ 22 tracking channels Ultra high tracking/navigation sensitivity: -165dBm1 tuned ceramic chip antenna SBAS (WAAS,EGNOS,MSAS,GAGAN, QZSS) correction support in high activity mode A-GPS by EPO "Extended Prediction Orbit" TM enables 7/14days prediction 12 Multitone Active Interference Canceller (MTAIC) for GPS-in-band jammer rejection EASY TM : 3 day self generated orbit prediction support High accuracy 1PPS output NMEA-0183 protocol, configurable High update rate (up to 10/s) in high activity mode Embedded logger function with 16hrs internal memory GPS current consumption (@3.3V): Acquisition: 22mA typical Tracking: 7mA typical Low backup current consumption 7uA, typical SMD type LGA Small form factor: 15.7x10x2.0mm Note: Measured navigation sensitivity at RF input of chipset 2 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 2 INDEX 1 INTRODUCTION ----------------------------------------------------------------------------------------- 1 2 INDEX --------------------------------------------------------------------------------------------------- 3 3 FUNCTIONAL DESCRIPTION ---------------------------------------------------------------------------- 4 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 System description ---------------------------------------------------------------------------------------------------------4 Block diagram --------------------------------------------------------------------------------------------------------------4 Power Management Features ----------------------------------------------------------------------------------------------5 EASYTM self generated prediction data feature ----------------------------------------------------------------------------7 Pulse Per Second (PPS) ----------------------------------------------------------------------------------------------------8 Logger function -------------------------------------------------------------------------------------------------------------8 Active interference cancellation (MTAIC) ---------------------------------------------------------------------------------9 SBAS (Satellite Based Augmentation) support ---------------------------------------------------------------------------9 GPS almanac and ephemeris data-----------------------------------------------------------------------------------------9 Real time clock (RTC) ------------------------------------------------------------------------------------------------------9 UART interface ------------------------------------------------------------------------------------------------------------ 10 Module default settings -------------------------------------------------------------------------------------------------- 10 4.1 Typical System Overview ------------------------------------------------------------------------------------------------ 11 5.1 GPS characteristics ------------------------------------------------------------------------------------------------------- 12 6.1 6.2 Absolute Maximum Ratings ---------------------------------------------------------------------------------------------- 13 Electrical characteristics ------------------------------------------------------------------------------------------------- 13 8.1 8.2 NMEA output sentences -------------------------------------------------------------------------------------------------- 16 NMEA command interface------------------------------------------------------------------------------------------------ 16 11.1 PCB LAYOUT GUIDELINES ----------------------------------------------------------------------------------------------- 19 12.1 12.2 NMEA output sentences -------------------------------------------------------------------------------------------------- 21 NMEA command interface------------------------------------------------------------------------------------------------ 21 15.1 15.2 TAPE ----------------------------------------------------------------------------------------------------------------------- 23 REEL ----------------------------------------------------------------------------------------------------------------------- 24 4 TYPICAL APPLICATION BLOCK DIAGRAM ------------------------------------------------------------ 11 5 GPS characteristics ----------------------------------------------------------------------------------- 12 6 ELECTRICAL SPECIFICATION ------------------------------------------------------------------------- 13 7 PIN CONFIGURATION --------------------------------------------------------------------------------- 14 8 NMEA DATA interface --------------------------------------------------------------------------------- 16 9 PHYSICAL DIMENSIONS ------------------------------------------------------------------------------ 17 10 RECOMMENDED PAD LAYOUT ----------------------------------------------------------------------- 18 11 DESIGN GUIDELINES -------------------------------------------------------------------------------- 19 12 NMEA DATA interface -------------------------------------------------------------------------------- 21 13 MATERIAL INFORMATION --------------------------------------------------------------------------- 22 14 RECOMMENDED SOLDERING REFLOW PROFILE --------------------------------------------------- 22 15 PACKAGE INFORMATION ---------------------------------------------------------------------------- 23 16 17 18 19 20 ORDERING INFORMATION -------------------------------------------------------------------------ENVIRONMENTAL INFORMATION ------------------------------------------------------------------MOISTURE SENSITIVITY ---------------------------------------------------------------------------DOCUMENT REVISION HISTORY -------------------------------------------------------------------RELATED DOCUMENTS ------------------------------------------------------------------------------ 25 25 26 26 26 3 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 3 FUNCTIONAL DESCRIPTION 3.1 System description The GNS302uLP is a high performance, ultra low power GPS receiver that includes an integrated RF frontend (SAW Filter + LNA) and a ceramic chip antenna. Due to high input sensitivity and low noise amplifier (LNA), it can work at weak GPS signals. GNS302uLP is a complete autonomous GPS receiver, including: - Full GPS processing, without any host processing requirements Standard NMEA message output A powerful NMEA command and control interface All clock sources integrated RF frontend integrates a two stage low noise amplifier (LNA) a SAW filter and a high performance chip antenna Interface for UART, PPS output pin, Fix Status Indicator pin 3.2 Block diagram GPS chip antenna 19 RESET 2 WAKEUP 4 3D-Fix 11 1PPS SAW filter +Low Noise Amplifier 9 RXB 8 TXA GPS chip 7 RXA VCC 14 32.768kHz crystal VBACKUP 13 26MHz TCXO GND 1,5,6,15,16,20 4 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 3.3 Power Management Features GNS302uLP uses an advanced hardware / firmware architecture to minimize power consumption at full navigation update rate of 1position per second. Best savings are possible with 6 SVs in track and good fieldstrength. uLP feature is a dynamic power management that allows to reduce the power consumption to ~40% in average. Thanks to advanced hardware and firmware architecture and unlike other power management features, uLP feature will calculate and output position data every second. uLP feature has been developed for fitness- and other wearable applications. The average accuracy will be slightly reduced (4m instead of 3m). For static or slow moving scenarios , the savings can be better than 70%. uLP feature is activated by default and can be deactivated through $PMTK262,0 command. Besides of the uLP power mode, the well known power savings modes with reduced output rate and performance are available when uLP is disabled. Power management schemes implemented for any GPS system requires an optimally tuned performance for both accuracy of the position fixes and the average power consumed for best user experience. GNS302uLP architecture achieves these both aspects by providing flexibility and design choices for the system integration, based on wide range of use cases and by leveraging on the proven silicon methodologies. Also GNS302uLP provides position, velocity and time measurements without any host loading. This, coupled with the optional built-in power management options, reduces the overall system power budget. Selectable Power management features: In Standby mode RF frontend and internal MPU are switched to deep sleep state. Power consumption is reduced.This state can be entered by sending the NMEA command: $PMTK161,0*28<CR><LF>. Leaving standby mode and resuming to normal operation will be managed by sending any byte to the module. Backup mode can be entered by sending NMEA command: $PMTK225,4*2F<CR><LF>. The GPS core will shut down autonomously to backup state, Vcc supply can now be switched off by an external power supply switch. 5 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification Periodic mode describes a power mode, which will autonomously power on/off the module in programmable time slots with reduced fix rate. Periodic mode is useful during stationary operation or if position fixes are just needed from time to time. Since power consumption in GPS off times is nearly zero, the power consumption in periodic mode can be estimated by Ptracking * (ton/(ton+toff)). Periodic mode is controlled with NMEA command $PTMK225. See document NMEAcommandInterface manual for programming details. AlwaysLocateTM feature provides an optimized overall GPS system power consumption in tracking mode under open sky conditions. Always Locate is an intelligent control of periodic mode. Depending on the environment and motion conditions, GNS302uLP can adjust the on/off time to achieve balance of positioning accuracy and power consumption. The best power saving will be made under good reception in stationary mode. Critical reception conditions and dynamic movements will need full activity of the GPS engine which causes nominal power requirements (20mA typ in tracking mode). 6 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 3.4 EASYTM self generated prediction data feature GNS302uLP includes an internal prediction system, that allows to sample satellite orbit data during operation and use that data to speed up TTFF on later starts.The prediction time frame is up to three days forward. Although this prediction feature does not provide the very short TTFF that is achieved using AGPS, it can help to find a fix solution faster and in weak signal condition scenario. Prediction data will be kept in memory as long as VBACKUP is present. This option is activated by default. Note: The EASY functionality is only supported, if "VBACKUP" pin is conntected and the NMEA update rate is 1Hz. 7 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 3.5 Pulse Per Second (PPS) GNS302uLP provides a Pulse Per Second (PPS) hardware output pin for timing purposes. After calculation of a 3D position fix (default setting), the PPS signal is accurately aligned to the GPS second boundaries. The pulse generated is approximately 100 milliseconds in duration and the repetition rate is 1 second. On request PPS output can activated on a 2D- fix or after power-up of the module, providing a time accuracy decreased PPS signal. T2 T1 T1 = 100ms T2 = 1sec GNS302uLP module provides an exceptionally low RMS jitter of typical 10 nanoseconds. 1PPS pulse duration 1PPS time jitter - 1PPS rise and fall time PPS characteristics based upon a 3D-fix 100 msec 10 nsec RMS 5 nsec Pulse rising edge deviation from expected pulse time, measured with full 3D fix 10%..90%, load is 10k||5pF 3.6 Logger function GNS302uLP provides an autonomous logger function that automatically stores position information in an internal 128kB flash memory. A complete tracking unit can be realized without any external CPU or memory. The parameters for logging are programmable via the NMEA command interface. The following parameter can be set to optimize logging time: - logger rate The commands for logger include: - start logging - stop logging - erase memory - readout memory please refer to the NMEAcommandInterface manual for details. 8 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification Logger data rate Logger data memory Logger trigger 1/15 Internal Logger Function 1 1/s 128 kBytes programm able Flash memory Logger can be triggered on various events 3.7 Active interference cancellation (MTAIC) Because different wireless technologies like Wi-Fi, GSM/GPRS, 3G/4G, Bluetooth are integrated into portable systems, the harmonic of RF signals may influence the GPS reception. The multi-tone active interference canceller can reject external RF interference which come from other active components on the main board, thus improving the performance of GPS reception. GNS302uLP can cancel up to 12 independent continuous wave (CW) channels having signal levels of up to -80dBm. The functionality is enabled by default and increases power consumption by about 1mA. 3.8 SBAS (Satellite Based Augmentation) support GNS302uLP supports Satellite Based Augmentation for improvement of the navigation precision. Correction data is sent from geostationary satellites to the GPS receiver. GNS302uLP supports European, US, and Asian augmentation systems (EGNOS, WAAS, GAGAN, MSAS, QZSS) to enable precision improvements in nearly every region of the world. SBAS is active by default and will automatically track the available SBAS satellites. It can be disabled by NMEA command. See document NMEAcommandInterface manual for details. Note: SBAS is deactivated in uLP mode. For SBAS activation, uLP mode must be disabled 3.9 GPS almanac and ephemeris data For quick re-acquisition of the GPS after off-times, the GPS engine should have access to almanac and ephemeris data. This data is permanently stored inside GNS302uLP module, even if all power supplies have been removed. When the GPS is powered-up again, the data will be used to allow a quick re-acquisition, as soon as a coarse time information is available. Time will be available immediately, when RTC is kept running. 3.10 Real time clock (RTC) GNS302uLP has a real time clock with 32,768Hz crystal onboard. As long as VBACKUP is connected to a power source, the real time clock and the module memory can be kept alive at very low power consumption of just 7uA. The RTC will track the current time and enable the module to start from sleep states with very fast time to first Fix (TTFF). 9 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 3.11 UART interface GNS302uLP core and I/O sections work at 3.3V nominal. Absolute Maximum Ratings should not be exceeded. Should the GNS302uLP be interfaced to a host with I/O at higher/lower levels, level shifters should be used. UART baud rate is 9600 baud by default. The baud rate can be modified to higher rates by a NMEA software command. See document NMEAcommandInterface manual for details. GPS UART Default Settings Parameter Value Baud rate Data length Stop bit Parity 9600 fixed 8 bits 1 None 3.12 Module default settings The GNS302uLP receiver comes with default settings, which are persistently programmed. Whenever power is removed from the module (both VCC and VBACKUP), the settings will be reset to the values shown in the following table. NMEA output sentences Setting Default value UART setting Fix frequency (update rate) NMEA sentences NMEA rate Self survey prediction mode: EASYTM Active interference cancellation:MTAIC Datum Logging parameters uLPower Feature Elevation mask 9600,8,N,1 1/sec $GPRMC,$GPGSA,$GPGSV,$GPGGA Once a second enabled enabled WGS 84 Wrap when full / Content Basic / Interval 15 sec Activated (disabled on request) 5 On request, other options can be selected as preprogrammed (persistent default) options. Please contact the GNS support for your project requirements. Note : Customized options are solely available for fixed order lots. 10 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 4 TYPICAL APPLICATION BLOCK DIAGRAM 4.1 Typical System Overview GNS 302uLP Power Management VCC V Backup 2.8 to 4.3V UART RX UART TX Host Processor MMI (keys, display) 11 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 5 GPS characteristics 5.1 GPS characteristics Parameter Min Typ Max Unit Note general Frequency SBAS Datum AGPS Output data frequency Navigation&tracking sensitivity1 Acquisition sensitivity1 Reacquisition sensitivity1 TTFF hotstart TTFF autonomous warm start TTFF autonomous warm start TTFF autonomous cold start Reacquisition time Number of channels tracking Number of acquisition channels Dimension Weight 1575.42 7 1/10 MHz 14 10 1 -165 -148 -163 1 34 5..10 35 <1 22 66 15.7x10x2 0.64 days 1/sec dBm dBm dBm sec sec sec sec sec GPS L1 C/A code WAAS,EGNOS,MSAS,GAGAN,QZSS1 WGS84 Configurable 1/s in uLP mode autonomous Cold start Hot start 6 SVs @-130dBm 6 SVs @-130dBm 6 SVs @-130dBm / with EASY on 6 SVs @-130dBm 6 SVs @-130dBm mm g Tolerance is 0.2 mm m m m/s m/s 2D-RMS Using (SBAS) , uLP mode disabled Note: 1) Only available when uLP mode is disabled Accuracy Position error (50%CEP) Position error (50%CEP) Velocity error velocity error - Frequency VSWR gain impedance Polarization - Operation altitude Operation velocity Operation acceleration 1 - 4 2.5 0.1 0.05 - Antenna specifications 1575.42 2 3.2 50 Linear - ITAR limits 18,000 515 4 MHz dB Ohm - Using (SBAS) , uLP mode disabled f = 1575.4 MHz peak@zenith , f = 1575.4 MHz f = 1575.4 MHz m m/s G note: based on chip specifications 12 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 6 ELECTRICAL SPECIFICATION 6.1 Absolute Maximum Ratings Parameter Supply voltage: Vcc Backup voltage: VBACKUP Input voltage to analog pins Input voltage to all other pins Operating ambient temperature range Storage temperature range Value Unit -0.5 to 4.3 -0.5 to 4.3 -0.5 to 3.3 -0.5 to Vcc -40 to +85 -50 to +125 V V V V C C 6.2 Electrical characteristics Parameter Min Typ Max Unit Vcc Vcc ripple voltage 2.8 3.3 4.3 50 V VBACKUP 2.0 3.0 4.3 V High level output voltage VOH 2.38 2.9 V 0 0.42 V High-level input voltage VIH Low-level input voltage VIL 2.1 -0.3 3.5 0.7 V V Operating temperature -40 85 C Low level output voltage VOL Note supply voltage mVpp Backup voltage for RTC and memory retention, must be available during normal operation Full specified sensitivity 13 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 7 PIN CONFIGURATION Top View 14 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification Pin 1 2 3 4 Name GND WAKEUP NC 3D_FIX I/O I Description & Note Ground Wakeup input (TBD) leave open O Not conected 3D-Fix Indicator The 3D_FIX is assigned as a fix flag output. If not used, keep floating. Before 2D Fix The pin will continuously toggle with 1 Hz. output 100ms high-level and 0.9s low-level signal After 2D or 3D Fix The pin will continuously output low-level signal This pin may not connected to high-level at power-on sequence. 5 6 7 GND GND RXA I Ground Ground Serial Data Input A for NMEA commands (TTL) 8 TXA O Serial Data Output A for NMEA output (TTL) 9 RXB I Serial Data Input B 10 11 NC 1PPS O Not connected 1PPS Time Mark Output 2.8V CMOS Level 12 13 NC VBACKUP P Not conected Backup power input for RTC & navigation data keep 14 VCC P Main DC power input 15 16 17 18 19 GND GND NC NC RESET I Ground Ground Not conected Not conected System reset pin 20 GND This is the UART-A receiver of the module. It is used to receive commands from system This is the UART-A transmitter of the module. It outputs GPS information for application. This is the UART-B receiver of the module. It is used to receive RTCM data from system This pin provides one pulse-per-second output from the module and synchronizes to GPS time. Keep floating if not used. This connects to the backup power of the GPS module. Power source (such as battery) connected to this pin will help the GPS chipset in keeping its internal RTC running when the main power source is turned off. The voltage should be kept between 2.8V~4.3V, Typical 3.3V. If VBACKUP power was not reserved, the GPS receiver will perform a lengthy cold start every time it is powered-on because previous satellite information is not retained and needs to be re-transmitted. This pin must be connected for normal operation. The main DC power supply for the module. The voltage should be kept between from 2.8V to 4.3V. The ripple must be limited under 50mVpp (Typical: 3.3V). An external reset applied to this pin overrides all other internal controls. RESET# is an active low signal. Pulling this pin low for at least 20 s causes a system reset. Ground (1) I = INPUT; O = OUTPUT; I/O = BIDIRECTIONAL; P = POWER PIN; ANA = ANALOG PIN. 15 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 8 NMEA DATA interface GNS302uLP provides NMEA (National Marine Electronics Association) 0183 compatible data. A set of proprietary NMEA commands are available to send control messages to the module. These commands are described in a separate document: NMEA_Interface_manual_MTK_Vx manual. For standard operation, no commands are needed; the module will start outputting NMEA sentences after power supply has been attached. GNS302uLP will always start communication output with 9600 bit per second. If non standard options are needed (f.e. other baud rate , other NMEA sequence) they can be programmed from host controller during runtime. Important note : options set by using NMEA command interface are not persistent! They will be lost when power is removed. A backup supply at VBACKUP will be sufficient to keep them. 8.1 NMEA output sentences NMEA output sentences Type content $GPRMC $GPGGA $GPGSA $GPGLL $GPGSV Common GPS sentences Recommended Minimum Navigation Information Fix Data, Time, Position and fix related data for a GPS receiver DOP and active satellites Geographic Position - Latitude/Longitude GPS Satellites in view 8.2 NMEA command interface GNS302uLP NMEA command interface allows to control settings and the extended functions. The command interface specification is available in an extra document: NMEA_Interface_manual_MTK_Vx manual. Two groups of commands are available: Setting commands do modify the behavior of the module. Note : modified settings will be valid as long as the module is powered through V BACKUP. (f.e. : setting of a new baud rate). After removing VBACKUP, all settings are reset to their default values. Action commands will perform the specified action one time after the command has been received. (f.e. : request for cold start) Commands are always started with $PTMK, directly followed by the command number 000..999. Each command must be terminated by *<chksum>and a <CR><LF>. The checksum calculation is simple, just XOR all the bytes between the $ and the * (not including the delimiters themselves). Then use the hexadecimal ASCII format. 16 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 9 PHYSICAL DIMENSIONS TOP VIEW all units in mm, tolerance is 0.2mm 2.00 0.90 0.55 17 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 10 RECOMMENDED PAD LAYOUT all units in mm Footprint Top View 18 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 11 DESIGN GUIDELINES Although GNS302uLP GPS receiver provides best performance at low power consumption, special care should be taken to provide clean signal and clean power supplies. Power lines should be blocked near to the receiver with low ESR capacitors. Radiated noise from neighbour components may also reduce the performance of the receiver. 11.1 PCB LAYOUT GUIDELINES GNS302uLP uses a high performance chip antenna design. For optimum performance, a ground plane area is needed on the main board. This area should be at least 20 x 30mm, a larger ground like 30 x 60mm is recommended. The groundplane can be part of the main ground layer of the mainboard, some (small) components in the neighbourhood of the antenna are acceptable. Do not place any bulky or metallic components near to the antenna (in a distance below 30mm) to avoid unwanted electromagnetic shielding effects. It's recommended to place GNS302uLP at the rim of the main PCB, so that the antenna has a wide unobstructed working angle. Groundplane on top & bottom. Be sure to solder these pads reliably ! Clearence area. Keep clear on all layers ! Position of chip antenna on 302uLP module 19 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification The marked clearance area below the antenna must be kept clear in any case ! Do not design any copper tracks or planes in the clearance area ! The two ground solder pads near the chip antenna must be reliably soldered to mainboard groundplanes to make the antenna work at high performance. Please do not place any shielding or lids in the area 5mm below your PCB under the Clearance area. Plastic enclosures can also have impact on the antenna. Avoid that the antenna is in touch with any enclosure parts. Product testing should be performed with the PCB already mounted in the final enclosure. Generally the rules for good and low noise design should be followed: Use a solid ground plane, best on layer 2 of the mainboard Keep noisy components (C, switch mode supplies) as far as possible away from sensitive antenna inputs Place decoupling capacitors near to the source of noise and provide a short and low induction connection to ground (use multi-vias if needed) EMC filters or noise filtering coils or beads can help to reduce the noise level further. Select system clocks in a way, that no harmonics will match the GPS frequency of 1575.42 MHz 20 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 12 NMEA DATA interface GNS302uLP provides NMEA (National Marine Electronics Association) 0183 compatible data. A set of proprietary NMEA commands is available to send control messages to the receiver. These commands are described in a separate document: NMEA_Interface_manual_MTK_Vx. For standard operation, no commands are needed; the module will start outputting NMEA sentences after power supply has been attached. GNS302uLP will always start communication output with 9600 bit per second. If non standard options are needed (f.e. other baud rate , other NMEA sequence) they can be programmed from host controller during runtime. Important note : Options set by using NMEA command interface are not persistent! They will be lost when power is removed. A backup supply at VBACKUP will be sufficient to keep them. 12.1 NMEA output sentences NMEA output sentences Type content $GPRMC $GPGGA $GPGSA $GPGLL $GPGSV Common GPS sentences Recommended Minimum Navigation Information Fix Data, Time, Position and fix related data for a GPS receiver DOP and active satellites Geographic Position - Latitude/Longitude GPS Satellites in view Refer to NMEA_Interface_manual_MTK_Vx document for more information. 12.2 NMEA command interface GNS302uLP NMEA command interface allows to control settings and the extended functions. The command interface specification is available in an extra document: NMEA_Interface_manual_MTK_Vx. Two groups of commands are available: Setting commands do modify the behavior of the module. Note : Modified settings will be valid as long as the module is powered through V BACKUP. (f.e. : setting of a new baud rate). After removing VBACKUP, all settings are reset to their default values. Action commands will perform the specified action one time after the command has been received. (f.e. : request for cold start) Commands are always started with $PTMK, directly followed by the command number 000..999. Each command must be terminated by *<chksum>and a <CR><LF>. The checksum calculation is simple, just XOR all the bytes between the $ and the * (not including the delimiters themselves). Then use the hexadecimal ASCII format. 21 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 13 MATERIAL INFORMATION Complies to ROHS standard ROHS documentations are available on request Contact surface: gold over nickel 14 RECOMMENDED SOLDERING REFLOW PROFILE T[C] 300 250C max 250C for 10 sec max 230C for 40 sec max 200 160C 190C 120 sec reflow solder 100 100 200 t[sec] Notes: 1. GNS302uLP should be soldered in upright soldering position. In case of head-over soldering, please prevent shielding / GNS302uLP receiver from falling down. 2. Do never exceed maximum peak temperature 3. Reflow cycles allowed : 1 time 4. RohS compliance status will be lost if soldered with solder containing lead (Pb). 5. This device is not applicable for flow solder processing 6. This device is not applicable for solder iron process 22 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 15 PACKAGE INFORMATION 15.1 TAPE 23 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 15.2 REEL : Number of devices: 1500 pcs/reel 24 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 16 ORDERING INFORMATION Ordering information Type GNS302uLP Part# 4037735105393 label marking GNS302uLP YYWW 2.5_39 SN Description GNS302uLP GPS receiver YYWW date code FW Version SN serial number 17 ENVIRONMENTAL INFORMATION This product is free of environmental hazardous substances and complies with 2002/95/EC. (RoHS directive). 25 V 0.2, Jan 26 2016 GPS receiver GNS302uLP Datasheet preliminary specification 18 MOISTURE SENSITIVITY This device must be prebaked before being put to reflow solder process. Disregarding may cause destructive effects like chip cracking, which leaves the device defective ! Shelf life 6 months , sealed Possible prebake recommendations 12 hrs @ 60C Floor life (time from prebake to solder process) <72 hrs 19 DOCUMENT REVISION HISTORY V0.1 V0.2 Sep 23 2015 Jan 26 2016 P.Skaliks P.Skaliks initial document, preliminary Laser marking def 20 RELATED DOCUMENTS Title Description / file Available from NMEA_Interface_manual_MTK_Vx Detailed description of NMEA commands and protocol www.forum.gns-gmbh.com www.gns-gmbh.com GNS GMBH 2015 THE INFORMATION IN THIS DOCUMENTATION DOES NOT FORM ANY QUOTATION OR CONTRACT. TECHNICAL DATA ARE DUE TO BE CHANGED WITHOUT NOTICE. NO LIABILITY WILL BE ACCEPTED BY THE PUBLISHER FOR ANY CONSEQUENCE OF THIS DOCUMENT'S USE. REPRODUCTION IN WHOLE OR IN PART IS PROHIBITED WITHOUT THE PRIOR WRITTEN CONSENT OF THE COPYRIGHT OWNER 26 V 0.2, Jan 26 2016