RoyalTek
Confidential
6
REB-1722 Operational Manual
1.5 Application Circuit
Reference schematic:
For example:
P.S. If active antenna short
=>Current >100mA , so U3 PIN3 OUT
open . So AADET0_N status is
high.
V_ANT_3V3
OK
AADET0_N
+
C1
0.1uF
OK
Active antenna status
VCC_3V3
Active antenna status
HIGH
VCC_3V3
V_ANT
Option 2
V_ANT
Micro
Active antenna select
2.7V~3.3 or 5V
VANT_3V3 or 5V
MAXIM / MAX4T
/ uDFN
R9
3.3K
V_ANT_3V3
Active Antenna open detect
circuit
RESET
+
C6
33uF
R6
4.3K
R3
4.7 ohm
AADET0_N
STATUS
+
C4
33uF/6.3V
R5
3.3K
R1
100K
AADET0_N
V_ANT
R5
3.3K
Processor
Active
VCC_3V3
U2
ZXCT1009
2
3
1
V
s
ens
e+
Vs
en
s
e
-
Iout
Active antenna
select 3.3V
V_ANT
C7
0.01uF
U3
MAXIM MAX4T
2
3
1
4
5
6
IN
OUT
N.C.
nFLAG
GND
ON
C10
0.1uF
R2
100K
Active antenna without
, or SHORT
Active antenna no
exist, or OPEN
LOW
V_ANT
R7 10K
Antenna
V_ANT_3V3
Active antenna
select 3.3 or 5V
R8
3.3K
(Serial)
HIGH
Q2
2SC2412K
3
2
1
VCC_RF
V_BACKUP
C2
0.1uF
AADET0_N
STATUS
C7
0.01uF
VC_RF
V_ANT_3V3
Active antenna short
detect circuit
NOHM
2SC2412K
SC-59
C9
0.01uF
V_ANT_3V3
C3
0.1uF
NOHM
2SC2412K
SC-59
V_ANT_3V3
Q1
2SC2412K
3
2
1
Active antenna Normal
suggest circcuit
AADET0_N
U1
REB-1722
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
SDA2
SCL2
TxD1
RxD1
NC
VCC
GND
VCC_OUT
CFG_COM1
RESET_N
V_BCKP
BOOT
GND
GND
GND
RF_IN
GND
VCC_RF
V_ANT
AADET0_N
NC
NC
NC
NC
NC
NC
EXTINT0
TIMEMARK
ZETEX
ZXCT1009
SOT23
(Optional)
LOW
Option 1
50 ohm trace
-
C8
1uF
R4 10K
Note:
(1)
Ground Planes:
These pins (7,13, 14, 15, 17) should be connected to ground.
(2)
Serial Interface:
(
Ⅰ
) The TxD1 pin is the serial output data (Default NMEA) .
(II) The RxD1 pin is the serial input data (Default NMEA) .
(3)
Backup Battery:
When module is working, must to supply VCC (P6) and V_BCKP (P11) power at
the same time.
It’s recommended to connect a backup battery to V_BCKP pin and to enable the
warm start and hot start features of the GPS receiver.
If you use backup battery, should be adding a bypassing capacitor (0.01~10uF) at
V_BCKP pin. It can reduce noise and increase the stability.
