RoyalTek Confidential
6
RET-3570LP User Manual
26 Operating
temperature
-40 ~ 85
℃
27 Humidity
≦
95%
1.6 Application Circuit
Reference:
Note:
(1) Ground Planes:
RET3570LP GPS receiver needs two different ground planes.
These pins(13
、
15
、
16
、
18) should be connected to analog ground.
These pins(2
、
10
、
30) should be connected to digital ground.
(2) Serial Interface:
(I)The TXA pin is recommended to pull up (10K
Ω
). It can
increase the stability of
serial data
.
(II)
The TXB pin is recommended to connect to serial resistance(220
Ω
) and pull
up (10K
Ω
), if use the DGPS output.
If the DGPS output is not used, it won’t connect anything.
(III) The RXB pin is recommended to connect to serial resistance(220
Ω
), if the DGPS
output is used.
If the DGPS output is not used, it won’t connect anything.
(3) 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 float it.
If you use a backup battery, you should add a bypassing capacitor (10uF) at V_RTC_3V3
pin to reduce noise and increase the stability.
(4) GPS_RF_IN:
Connecting to the antenna has to be routed on the PCB. The transmission line must control