PMB 248 Spec Specification
User Manual: parallax -
Open the PDF directly: View PDF 
.
Page Count: 6
PMB-248 ISSUED DATE 2005/09/14 PUBLISHED BY
VERSION 01
PRODUCT NAME GPS Receiver Module PAGE 2/7
Polstar Technologies Inc.
All right reserved by Polstar Technologies Corporation.
SPECIFICATION
SPEC NO. : PMB-248
PART NO. ： PMB-248
PRODUCT NAME ： GPS Receiver / PMB-248
DESCRIPTION ： GPS Receiver (RS232,TTL , Baud Rate
4800bps)
REVISION STATUS
VERSION DATE PAGE REVISION DESCRIPTION PREPARED DESIGNED APPROVED
01 2005/09/14 all pages New Issued Ken Hung Ken Hung S.M. Wang
Prepared By Designed By Approved By
PMB-248 ISSUED DATE 2005/09/14 PUBLISHED BY
VERSION 01
PRODUCT NAME GPS Receiver Module PAGE 3/7
Polstar Technologies Inc.
All right reserved by Polstar Technologies Corporation.
INDEX
Item No. Contents Page
1.0 Cautions 3
2.0 Electrical Characteristics 4
3.0 Normal Operating Conditions 4
4.0 Specification 4
5.0 Time To First Fix (TTFF) 6
6.0 Interface 6
7.0 Communication Specification 6
8.0 LED Indication 6
9.0 Module I/O Connector Pins 6
10.0 Dimension 7
PMB-248 ISSUED DATE 2005/09/14 PUBLISHED BY
VERSION 01
PRODUCT NAME GPS Receiver Module PAGE 4/7
Polstar Technologies Inc.
All right reserved by Polstar Technologies Corporation.
1.0 Cautions
GPS (Global Positioning System) is a satellite-based navigation system. In an unobstructed clear
view of the sky, GPS works anywhere in the world, 24 hours a day.
GPS is developed and operated by the government of United States. Under the policy of the
government, the degradation in accuracy shall occur without prior warnings, and sometimes
satellites don’t transmit signal due to adjustment, test, and orbital revision.
Also, please note:
1. products such as motors, computer, and RF devices, which emit high levels of
magnetic field and interference that may cause the performance of the GPS unit to drop.
2. the optimal position during automobile applications is on the roof top of the vehicles. If the
GPS unit is to be placed inside the car, be certain to avoid coverage by metal objects for
optimal performance.
Please be aware that the performance of the GPS receiver module does not warrant against the
above factors.
(Position Accuracy)
Position data and position accuracy are affected or degraded by the satellite geometry,
electric magnetic interference, and multipath.
(Equipment)
The high frequency noise will interfere with signal receiving. The high frequency noise within the
receiver frequency band, 1575Mhz ±10MHz, will affect the receiver quality. Also, because of
the mixer and modulation, the low frequency noise will be increased by several times. If this
increased frequency drops into the 1575MHz ±10MHz band, it will also affect the receiver
quality.
(Warranty)
If the product fails within one year after the date of delivery while it has been used properly
it will be replaced or repaired free of charge.
PMB-248 ISSUED DATE 2005/09/14 PUBLISHED BY
VERSION 01
PRODUCT NAME GPS Receiver Module PAGE 5/7
Polstar Technologies Inc.
All right reserved by Polstar Technologies Corporation.
2.0 Electrical Characteristics Vcc=3.3V
Symbol Parameter Min Typ Max Units
Vcc Operation Voltage 3.0 3.3 5.5 V
VIH Input High Voltage 2.0 ─ ─ V
VIL Input Low Voltage ─ ─ 0.8 V
VOH Output High Voltage 2.4 ─ ─ V
VOL Output Low Voltage ─ ─ 0.4 V
IL Input Leakage Current ─ ─ 2 μA
Cin Input Capacitance ─ ─ 3 pF
Cout Output Capacitance ─ ─ 3 pF
3.0 Normal Operating Conditions
Symbol Parameter Min Typ Max Units
VCC Power Supply Voltage 3.0 3.3 5.5 V
VIN Input Pin Voltage 0 ─ 3.3 V
Pw Power Consumption(*1) ─ 80 ─ mA
Top Operating Temperature -40 25 70
°C
*1: Power Consumption: Typical: 80mA @3.3V
4.0 Specification
Satellite Tracking 12 Parallel channels
RF input Center frequency 1575.42MHz L1 band, C/A code
Signal sensitivity -152 dBm or less
Positioning system Default WGS-84
Software Selectable All major coordinate systems
Positioning accuracy Position Approximately 2m, WAAS/EGNOS Support
Velocity 0.1m/s Average (without SA imposed)
Positioning condition First Time 3 Satellites
Navigation Update Rate 1second
Operation Temperature －10℃ to 70℃
Storage Temperature －40℃ to 100℃
PMB-248 ISSUED DATE 2005/09/14 PUBLISHED BY
VERSION 01
PRODUCT NAME GPS Receiver Module PAGE 6/7
Polstar Technologies Inc.
All right reserved by Polstar Technologies Corporation.
5.0 Time To First Fix (TTFF)
Assumes previously listed navigation conditions and 8 satellites in view
TTFF Typ Units
Hot Start (time, position, valid ephemeris, and valid almanac) 2 seconds
Warm Start (time, position, no ephemeris, and valid almanac) 33 seconds
Cold Start (time, position, no ephemeris, and valid almanac) 40 Seconds
The G-mouse has to establish location fix before accurate time information can be provided.
6.0 Interface
I/O connector (Power supply, serial data I/0) pitch 1.25mm 6pin Molex Male
7.0 Communication Specification
Communication method Start-stop synchronization
Transfer rate input/output 4800bps NMEA
Logic levels TTL
I/O code ASCII
Communication format NMEA
8.0 LED Indicate function
status Description LED ON / OFF TIME
1 The GPS is In-fix status Always ON
2 The GPS is Not-fix status Flashing
3 The GPS is out of power Always OFF
9.0 Module I/O Connector Pins
Pin Configuration
Pin
No. Symbol I/O Description
1 TTL TX O TTL TX
2 TTL RX I TTL RX.
3 VCC I Power supply input.
4 GND G Power & Data ground.
5 TX O RS232-TX
6 RX I RS232-RX
Pin 1 pin6
PMB-248 ISSUED DATE 2005/09/14 PUBLISHED BY
VERSION 01
PRODUCT NAME GPS Receiver Module PAGE 7/7
Polstar Technologies Inc.
All right reserved by Polstar Technologies Corporation.
10.0 Dimension
