RoyalTek REB-1315LPNX - Manual (Page 8)

RoyalTek Confidential 8
REB-1315LPNX Operational Manual
Note:
(1) Ground Planes:
These pin(18、20、21、22) should be connect to ground.
(2) Serial Interface:
(Ⅰ)The TXA pin is the serial output data. Default output GPS protocol. (NMEA sentence).
(Ⅱ). The RXA pin is the serial input data. Default output GPS protocol. (NMEA sentence)
(Ⅲ) The TXB pin is the serial output data (Default Null)
(Ⅳ) The RXB pin is the serial input data (Default Null).
(3) Backup Battery:
It’s recommended to connect a backup battery to V_RTC_3V3 pin.
In order to enable the warm start and hot start features of the GPS receiver.
If you use backup battery, should be adding a bypassing capacitor (10uF) at
V_RTC_3V3 pin. It can reduce noise and increase the stability.
(4) RF_IN:
Connecting to the antenna has to be routed on the PCB. The transmission line must
to be control impedance from RF_IN pin to the antenna or antenna connector of
your choice. (Impedance 50Ω)
(5) Power:
Connect V_GPS_3V3 pin to DC 3.3V. The power supply must add bypass capacitor
(10uF and 1uF).It can reduce the Noise from power supply and increase power
stability.
(6) Active antenna bias voltage:
The RF_OUT pin (pin 17) is provide voltage 2.85V. If you use active antenna, you
can use this pin to provide bias voltage for active antenna, but you must design the
RF chock circuit to avoid the RF signal jamming.
P.S. :
(1) This pin can provide maximum current is 30mA @ 2.85V.
(2) The active antenna input gain ranges are recommend 25~ 30dB.
(7) GPIO:
The GPIOs functions are for customer used.
If no use GPIO functions, it doesn’t connect anything.