RoyalTek Confidential
MEB-1315 User Manual
1.6 Application Circuit
Reference schematic:
RXB
R4
0
Ω
R10
open
50 ohm trace
C12
10uF
TP4
1
C11
10uF
L5
39nH
U2
OPEN(MEB-1315)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
RXB
TXB
PPS
TXA
RXA
GPIO-10
GPIO-0
GPIO-1
NC
/STANDBY
V_RTC_3V3
VIN_3V3
VDD_USB
VDD_DM
VDD_DP
NC
RF_VOUT
GND
GPS_RF_IN
GND
GND
GND
R3
OPEN
+3V3
TXA
+3V3
C10
0.1uF
RXA
TP3
1
+3V3
Active antenna
R5
0
Ω
R12
10k
RF matching circuit
U306
1
2
3
TP5
1
R6
OPEN
USB+
Battery
R11
470 ohm
C10
0.1uF
R7
33
Ω
R3
open
U304
ROHM RB705D
1
3
2
TXB
R8
33
Ω
U305
ROHM RB705D
1
3
2
+3V3(alway s)
USB-
GAIN:1 stage LNA 17dB
J2
U.FL-R-SMT
3
2
1
Note:
(1) Ground Planes:
These pins(18
、
20
、
21
、
22) should be connected 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 features of the warm start and hot start of the GPS receiver.
(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
