Globalsat ET-314AC User Manual [ru]

GLOBALSAT GPS Engine Board

Hardware Data Sheet

Product No : ET-314AC

Version 2.2

Issue Date

2010/04/01

2010/4/1

APPR

Ray

Globalsat Technology Corporation

16F., No. 186, Jian-Yi Road, Chung-Ho City, Taipei

Hsien 235, Taiwan

Tel: [phone] Fax: [phone]

E-mail : [e-mail]

Website: www.globalsat.com.tw

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ET-314AC
High Performance GPS Engine Board

Product Description

Product Description

ET-314AC is a compact, high performance, and low power consumption GPS engine board. It
uses SiRF Star III chipset which can track up to 20 satellites at a time and perform fast TTFF in
weak signal environments. ET-314AC is suitable for the following applications:

z Automotive navigation
z Personal positioning
z Fleet management
z Mobile phone navigation
z Marine navigation

Product Features

z SiRF star III high performance GPS Chipset
z Very high sensitivity (Tracking Sensitivity: -159 dBm)
z Extremely fast TTFF (Time To First Fix) at low signal level
z Two serial ports
z 4Mb flash
z Built-in LNA
z Compact size (25.4mm * 25.4 mm * 2.50mm) suitable for space-sensitive application
z One size component, easy to mount on another PCB board

z Support NMEA 0183 V2.3 (Output: GGA, GSA, GSV, RMC, VTG, GLL, ZDA)

z Support SiRF binary protocol
z Active antenna detect

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ET-314AC
High Performance GPS Engine Board

Product Block Diagram

Product Pin Description

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ET-314AC
High Performance GPS Engine Board

PIN Number(s) Name Type Description Note

1 VCC P Main power supply to the engine board.

2,10,30 GND P Ground.

3 BOOTSEL I Set this pin to high for programming flash. 2

This is the main receive channel for receiving

4 RxD0 I

software commands to the engine board from
SiRFdemo software or from user written
software.
This is the main transmits channel for
outputting navigation and measurement data

5 TxD0 O

to user’s navigation software or user written

software. Output TTL level, 0V ~ 2.85V.
6 TxD1 O Serial output (default null)
7 RxD1 I Serial input (default null) 1
8

GPIO14 I/O General purpose I/O

9,25,26 NC ET-314AC reserves PIN

11,12,13,14,

GND_A P GPS RF Ground.

15,16,18

17. RF IN RF GPS antenna input
19 V_ANT I Antenna Bias voltage
20 VCC_RF O Supply Antenna Bias voltage (V=VCC)

1

1,3

21 V_BAT P Backup battery supply voltage
22 RESET I System reset (active low)
23 VDD28OUT O Output voltage 2.85V
24 GPIO1 I/O General purpose I/O 2,3
27 GPIO13 I/O General purpose I/O 1,3
28

GPIO15 I/O

General purpose I/O 1,3

29 1PPS O One pulse per second output. 2,3

<Note>

1. Internal pull-up resistor (100K nominal).

2. Internal pull-down resistor (100K nominal).

3. Default input at reset.

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ET-314AC
High Performance GPS Engine Board

Electrical Specification

Absolute Maximums Ratings

Parameter Min. Typ. Max. Conditions Unit
POWER Supply
Main power supply 3.1 3.3 3.5 V
Backup battery supply 2.0 3.5 V
Main power supply Current 23.80 26.24 26.70 mA
Backup battery supply Current 4.5 5.0 12.6 uA
Interface (VCC = 3.3V, VBAT= 3.3V, Operation Temp.= 25℃)

High Level input Voltage 0.7*VDD 3.5 V
Low Level input Voltage -0.3 0.3*VDD V
High Level input Current -10 10

60

Low Level input Current -10 10

-60
High Level output Voltage 0.75*VDD V
Low Level output Voltage 0.25*VDD V
RF Input
Input Impedance 50 
Operating Frequency 1.575 Ghz
☆ VDD is 2.85V for SiRF STARIII CHIP

(V=2.85V)

uA

(with Pull Low)
(V=0V)

uA

(with Pull High)

Receiver Performance

Sensitivity Tracking:-159dBm
Cold Start 42 seconds, average

Warm Start 38 seconds, average

Hot Start 1 second, average

Reacquisition 0.1 second, average

Maximum Altitude

Maximum Velocity

Maximum Acceleration

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Accuracy Position:

10 meters 2D RMS
1-5 meters 2D RMS, WAAS corrected.
Velocity: 0.1 m/s
Time: 1us synchronized to GPS time

＜

18,000 meter

＜

515 meter/ second

＜

4G

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ET-314AC
High Performance GPS Engine Board

Environmental Characteristics

Parameter Min Typ Max Unit
Humidity Range 5 95 % non-condensing
Operation Temperature -40 25 85
Storage Temperature -40 85

Physical Characteristic

Type 30-pin stamp holes

Dimensions 25.4 mm *25.4 mm * 2.50 mm ±0.2mm

Package Dimensions

℃
℃

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ET-314AC
High Performance GPS Engine Board

Application

Application Circuit

POWER Circuit

GPS POWER

VIN

C1

22UF/10V

U1

1

VIN

2
3

XC6209B332MRN 3.3V

VOUT
GND
CE

NC

5

4

C2

10UF/16V

L1

BLM18AG121SN1D

C3

470PF

GPS Active Antenna Specifications (Recommendation)

Frequency: 1575.42 + 2MHz Amplifier Gain: 18~22dB Typical
Axial Ratio: 3 dB Typical Output VSWR: 2.0 Max.
Output Impedance: 50 Noise Figure: 2.0 dB Max

GPS_3V3

Polarization: RHCP Antenna Input Voltage: 2.85V (Typ.)

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