USGlobalsat ET-314 - Manual (Page 6)

ET-314
The Specifications are subject to be changed without notice. Copyright © 2007, GlobalSat Technology.
Page 6 of 19
Version 1.2
Boot select
Set this pin to high for programming flash.
RXA
This is the main receiver channel and is used to receive software commands to the board from
SIRFdemo software or from user written software.
PS: Pull up if not used.
RXB
This is the auxiliary receiving channel and is used to input differential corrections to the board to
enable DGPS navigation.
PS: Pull up if not used.
TXA
This is the main transmitting channel and is used to output navigation and
measurement data to SiRFdemo or user written software.
TXB
For user’s application (not currently used).
RF_ON
This pin indicates state of RF voltage.
RF_IN
This pin receiver signal of GPS analog .due to the RF characteristics of the signal the design has
to certain criteria. The line on the PCB from the antenna(or antenna connector) has to be a
controlled microstrip line at 50Ω
V_ANT_IN
This pin is reserved an external DC power supply for active antenna.
If using 3.3V active antenna, pin 19 has to be connected to pin 20.
If the bias voltage of active isn’t 3.3V,you can input bias voltage of you need to this pin.
VCC_RF
This pin provides DC voltage 3.3 for active antenna. Reset