Skylab SKG12BL Datasheets
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GPS Module DataSheet
Name: Ultra High Sensitivity and Low Power GPS Receiver Module
Model No.: SKG12BL
Revision: 01
Revision History:
Revision Description Approved Date
001 Initial Release to 001
Woody
20120708
Skylab SKG12BL Datasheets
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DS-SKG12B-V1
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General Description
The SKG12BL is a complete GPS engine module
that features super sensitivity, ultra low power and small
form factor. The GPS signal is applied to the antenna
input of module, and a complete serial data message with
position, velocity and time information is presented at
the serial interface with NMEA protocol or custom
protocol.
It is based on the high performance features of the
MediaTek MT3337 single-chip architecture, Its
–165dBm tracking sensitivity extends positioning
coverage into place like urban canyons and dense foliage
environment where the GPS was not possible before.
The small form factor and low power consumption make
the module easy to integrate into portable device like
PNDs, mobile phones, cameras and vehicle navigation
systems.
Applications
LBS (Location Based Service)
PND (Portable Navigation Device)
Vehicle navigation system
Mobile phone
Figure 1: SKG12BL Top View
Features
Ultra high sensitivity: -165dBm
Extremely fast TTFF at low signal level
Built-in 12 multi-tone active interference canceller
Ultra low power consumption
±10ns high accuracy time pulse (1PPS)
NMEA Output：GGA,GSA,GSV,RMC
Advanced Features: AlwaysLocate; AIC; EPO
QZSS、SBAS (WAAS, EGNOS, MSAS, GAGAN)
UART interface: 4800/9600/38400/115200 bps
Small form factor: 16.0 x 12.2 x 2.4mm
RoHS compliant (Lead-free)
Pin Assignment
Figure 2: SKG12BL Pin Package
Skylab SKG12BL Datasheets
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Pin Description
Pin No. Pin name I/O Description Remark
1 FIXLED O Fixed LED Output Leave open if not used
2 GPIO11 I/O General Purpose I/O Leave open if not used
3 PPS O Time Pulse Signal (Default 100ms) Leave open if not used
4 EXTINT1 I External Interrupt Leave open if not used
5 NC
6 NC
7 NC
8 V_ANT I Active Antenna External Voltage Supply Leave open if not used
9 VCC_OUT O VCC power output Leave open if not used
10 GND G Ground
11 RF_IN I GPS Signal Input 50Ω@1.57542GHz, DC block inside
12 GND G Ground
13 GND G Ground
14 GPIO14 I UART Baudrate Selection. Leave open if not used
15 GPIO15 I UART Baudrate Selection. Leave open if not used
16 NC
17 NC
18 TXD1 I/O UART Serial Data Output 1 Leave open if not used
19 RXD1 I/O UART Serial Data Iutput 1 Leave open if not used
20 TXD0 O UART Serial Data Output 0 Leave open if not used
21 RXD0 I UART Serial Data Input 0 Leave open if not used
22 V_BCKP I RTC and backup SRAM power
This pin may be connect to Battery or
Power Supply(2.0~4.2V)
23 VCC P Module Power Supply Operating range: 3.0V to 4.2V
24 GND G Ground Leave open if not used
Interfaces Configuration
Power Supply
Regulated power for the SKG12BL is required. The input voltage Vcc should be 3.0V to 4.2V range, current is no less
than 100mA. Suitable decoupling must be provided by external decoupling circuitry (10uF and 1uF). It can reduce the
Noise from power supply and increase power stability.
Main power supply Vcc current varies according to the processor load and satellite acquisition. Maximum Vcc peak
current is about 30 mA during acquisition.
Backup Battery Power
In case of a power failure on pin Vcc, real-time clock and backup RAM are supplied through pin V_BCKP. This
enables the SKG12BL GPS Receiver to recover from power failure with either a hot start or a warm start (depending
on the duration of Vcc outage). If no Backup Battery is connected, the receiver performs a cold start upon powered up.
Skylab SKG12BL Datasheets
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Backup Battery Power V_BCKP draws typically 7 uA current in backup state.
RESET
The SKG12BL modules include a RESET pin. Driving RESET low activates a hardware reset of the system. RESET
is only an input and will not reset external circuitry. At power down the reset is forced when the Vcc drops below
2.7V.
NOTE
Ifnotused,leaveRESETnotconnected(floating).
Antenna
The SKG12BL GPS receiver is designed for supporting the active antenna or passive antenna connected with pin
RF_IN. The gain of active antenna should be no more than 25dB (18~20dB Typical). The maximum noise figure
should be no more than 1.5dB and output impedance is at 50 Ohm.
NOTE
Withpassiveantennakeepthecablelossatminimum
(<1dB).
Vcc_out
Antenna power output pin. When user wants to use external active antenna. The pin supply power for active antenna.
UART Ports
There are several function in SKG13B related to UATR communication, such as UART data transmission/receive and
NMEA sentences input/output. In general, UART0 is as NMEA output and PMTK command input, UAR1 as RTCM
input. The bit rates are selectable from 4800,9600,38400,115200 bps (see table).
.
Baud rate Pin14 Pin15
9600bps NC NC
4800 10K pull-down NC
115200 NC 10K pull-down
38400 10K pull-down 10K pull-down
EINT1
The default EINT1 function is Standby mode control but the function is not supported; leave signal floating (not
connected).
RF_IN
The transmission line must to be control impedance from RF_IN pin to the antenna or antenna connector of your
choice. (Impedance 50Ω)
PPS
A pulse per second (1 PPS) is an electrical signal that very precisely indicates the start of a second. Depending
on the source, properly operating PPS signals have an accuracy ranging 10ns. The PPS signals are used for
precise timekeeping and time measurement.
FIXLED
The default FIXLED function is valid fix indicator output. Without a valid fix the signal is at low state; during valid
Skylab SKG12BL Datasheets
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fix condition the signal outputs 50ms pulses every seconds.
Advanced Software Features
AlwaysLocate™
AlwaysLocateTM is an intelligent controller of periodic mode. Depending on the environment and motion conditions,
GPS module can adaptively adjust working/standby time to achieve balance of positioning accuracy and power
consumption. In this mode, the host CPU does not need to control GPS module until the host CPU needs the GPS
position data. The following flow chart is an example to make GPS module go into AlwaysLocateTm mode and then
back to normal operation mode.
AGPS Support for Fast TTFF (EPO™)
The AGPS (EPO™) supply the predicated Extended Prediction Orbit data to speed TTFF ,users can download the
EPO data to GPS engine from the FTP server by internet or wireless network ,the GPS engine will use the EPO data to
assist position calculation when the navigation information of satellites are not enough or weak signal zone .
Embedded Logger function
The Embedded Logger function don’t need host CPU (MCU ) and external flash to handle the operation , GPS Engine
will use internal flash (embedded in GPS chipset ) to log the GPS data (Data format : UTC, Latitude , longitude,
Valid ,Checksum ), the max log days can up to 2 days under AlwaysLocate™ condition .
AIC_Multi-tone active interference canceller
Because different application (Wi-Fi , GSM/GPRS,3G/4G,Bluetooth )are integrated into navigation system , the
harmonic of RF signal will 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 , to improve the capacity
of GPS reception without any needed HW change in the design .SKG12BL can cancel up to 12 independent
channel interference continuous wave.
Performance Specification
Parameter Specification
Receiver Type L1 frequency band, C/A code, 22 Tracking / 66 Acquisition-Channel
Sensitivity Tracking
Acquisition
-165dBm Typical
-148dBm Typical
Accuracy
Position
Vel oc ity
Timing (PPS)
3.0m CEP50 without SA(Typical Open Sky)
0.1m/s without SA
10ns RMS
