specifications for gps receiver - wless.ru v1.1 spec.pdf · gps performance will be optimum when an...

LOCOSYS Technology Inc.N 25°03.716’ E 121°38.742’ www.locosystech.com

© 2008 Locosys Technology Inc. All rights reserved. /13 Confidential - Information is subject to change without prior notice.

Specifications for

GPS receiver

LS-9548N

http://www.locosystech.com



Introduction The Locosys LS-9548N module is a high sensitivity, low power, SMD type 20 channels with built-in high gain LNA L1 GPS receiver design for portable and AVL applications. The LS-9548N is designed to allow easy and quick integration into customer applications.

Features l Based on the high performance ATHEROS® uN3010 single chip solution. l Compact module size for easy integration: 24mm x 20mm (0.94x0.79 in). l Orion v2.2 software which provides support for conventional GPS

operation.

Performance Specifications l L1 ( 1575.42 MHz ) frequency, C/A code, 20-channel, continuous tracking

receiver. l Navigation Sensitivity / Signal Tracking Sensitivity: -156 dBm / -159 dBm. l Update rate: NMEA @1Hz. l Cold / Hot Start Time: 39 s / 4 s @-130dBm. l Accuracy: Horizontal: <1.5 meters (50%), <3.2 meters (95%) l Speed accuracy: 0.1 m/sec.

Data Interfaces l NMEA-0183 messages. l Baud Rate: 4800, 9600, 19200, 38400, 57600 bps (default 9600 bps). l Data / Power / RF through 28 surface mount pads.

Physical Specifications l length: 24.0 mm ± 0.1 mm l width: 20.0 mm ± 0.1 mm l thickness: 2.7 mm max l weight: 2.1 g l operating temperature: -30 °C to +85 °C l storage temperature: -40 °C to +85 °C




Electrical Characteristics l Input power range: 3.0 to 3.6 VDC l Power consumption: 43 mA (max) at 3.3 VDC. l Backup power consumption: 14 μA at 3.0 VDC.

Parameter Description Input voltage 3.0 to 3.6 VDC Current (max) at 3.3 VDC 43 mA Battery backup voltage 1.8 to 3.6 VDC Battery backup current 14 uA at 3.0 VDC

External Antenna Voltage l The VANT input pad (pin 25) is supplied to the external active antenna. The

receiver does not use this supply and does not current limit in the event of a short circuit.

l The receiver will operate with a passive antenna with unity gain. However, GPS performance will be optimum when an external active antenna is used. The gain of this active antenna could be in the range of 14 to 27 dB.

Timemark 1PPS output l The 1PPS output of the receiver is < 1 μs.

Battery Backup l The SRAM and RTC(Real Time Clock) can kept operating by supplying

power from the VSTBY input pad(pin 16) during powered off conditions.




Performance Characteristics l Time-To-First-Fix (TTFF) is a measure of the elapsed time required for a

receiver to acquire the satellite signals and navigation data, and calculate the first position solution.

l The below table show the TTFF for the acquisition mode at -130 dBm and

-143dBm level:

Acquisition Mode @ -130 dBm Cold Start TTFF 39 s

Warm Start TTFF 37 s Hot Start TTFF 4 s

Acquisition Mode @ -143 dBm Cold Start TTFF 153 s

Warm Start TTFF 89 s Hot Start TTFF 16 s




l Navigation sensitivity: the lowest level at the GPS receiver which a valid

position fix is available. l Signal tracking sensitivity: the lowest level at which the GPS receiver reliably

tracks at least one satellite. l The LS-9548N’s sensitivity is measured as below block diagram, the cable

loss between GPS simulator and LS-9548N is 0.7 dB.

Without external LNA

Navigation sensitivity -156 dBm Signal tracking sensitivity -159 dBm

l Use a 16dB LNA to simulate external antenna as below block diagram, the

sensitivity will gain 1dB more.

With 16 dB LNA (Low Noise Amplifier)

Navigation sensitivity -157 dBm Signal tracking sensitivity -160 dBm




NMEA output messages l The output NMEA messages for the receiver are listed in below table.

NMEA message Description Update Rate

GSV GNSS Satellites in View 1Hz

VTG Course Over Ground and Ground Speed 1Hz

RMC Recommended Minimum Specific GNSS Data 1Hz

GSA GNSS DOP and Active Satellites 1Hz

GLL Geographic Position – Latitude / Longitude 1Hz

GGA Global Positioning System Fixed Data 1Hz




Block Diagram




Pin Assignment




Pin Definition Pin Name Type Description

1 NC No Connection 2 NC No Connection 3 NC No Connection 4 RXB I CMOS level asynchronous input for UART B 5 RXA 1 I CMOS level asynchronous input for UART A 6 TXA O CMOS level asynchronous output for UART A 7 NC No Connection 8 TIMEMARK O 1 PPS output 9 NC No Connection

10 NC No Connection 11 NC No Connection 12 NC No Connection 13 NC No Connection 14 GND P Ground 15 VCC P Main power input ( 3.0 – 3.6VDC ) 16 VSTBY 2 P Backup Battery Input ( 1.8 – 3.6VDC ) 17 BOOTSEL# I Keep floating ( For internal manufacturing use ) 18 RESET# I Keep floating ( System Reset, active low ) 19 NC No Connection 20 GND P Ground 21 NC No Connection 22 NC No Connection 23 TXB O CMOS level asynchronous output for UART B 24 NC No Connection 25 VANT External active antenna power input ( 3.0 – 3.3VDC ) 26 RFGND RF RF ground 27 RFIN RF RF input 28 RFGND RF RF ground

Note: 1. Should not float the RXA pin, this pin should be pulled high by a resistor no greater than 100K ohms. 2. The VCC and VSTBY should be provided at the same time.




Reference Design




Recommended PCB Land Pattern

Unit: mm




Issues and Feedback Locosys appreciates any kinds of feedbacks and bug reports. If you have any suggestions to improve GPS performance or if you find a bug, please email us at [email protected]

Revision History l Version 1.0: 2008-Mar-13 first release. l Version 1.1:

1. Change uNAV® to ATHEROS® 2. Add operating temperature and storage temperature. 3. Change backup voltage range. 4. Modify block diagram.


mailto:[email protected]

specifications for gps receiver - wless.ru v1.1 spec.pdf · gps performance will be optimum when an...

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