RoyalTek MEB-1000 - Manual (Page 11)

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MEB-1000 User Manual
1.8 Application Circuit
Figure 4 Application Circuit
Note:
(1) Serial Interface:
(Ⅰ)The TXA & RXA pin is recommended to connect to serial resistance(220
Ω ) and pull up (10KΩ). It can increase the stability of serial data.
(Ⅱ)The TXB & RXB pin is recommended to connect to serial resistance(220
Ω ) and pull up (10KΩ), if use the DGPS output.
If no use DGPS output, it don’t connect anything.
(2) Backup Battery:
It’s recommended to connect a backup battery to V_RTC_3V3.
In order to enable the warm start and hot start features of the GPS receiver.
If you don’t intend to use a backup battery, connect this pin to GND or open.
If you use backup battery, should be add a bypassing capacitor (10uF) at
V_RTC_3V3 pin. It can reduce noise and increase the stability.
(3) GPS_RF_IN:
Connecting to the antenna has to be routed on the PCB. The transmission
line must to controlled impedance to connect RF_IN to the antenna or
antenna connector of your choice. (Impedance 50Ω)
(4) Power:
Connect V_GPS_3V3 pin to DC 3.3V. The power supply must add bypassing