V1.4 – Mar-11
User’s Manual
Page 13 of 39
A1084-A
GSC3f/LPx
serial
Vbak
Tx
Rx
GND
3.3V
A
B
Vbak
GND
Vbak
GND
S
upe
rc
ap
Ba
tt
er
y
C
6
+
+
Back-up supply options
(A)
Supercap, charged through GPS module
(B)
Primary cell, decoupled with diode
NSR0310
ANT_EXT
ANT_GND
VANT
ANT_SW*
Vcc
* ANT_SW on HIGH to set
module to external antenna
10
0
Ω
10
0
Ω
GND
GND
50
Ω
RF termination
Shown from top without lid; pads shown for better understanding
Pin 0
marker
A1084-A
GSC3f/LPx
serial
Vbak
Tx
Rx
GND
3.3V
A
B
Vbak
GND
Vbak
GND
S
upe
rc
ap
Ba
tt
er
y
C
6
+
+
Back-up supply options
(A)
Supercap, charged through GPS module
(B)
Primary cell, decoupled with diode
NSR0310
ANT_EXT
ANT_GND
VANT
ANT_SW*
Vcc
* ANT_SW on HIGH to set
module to external antenna
10
0
Ω
10
0
Ω
GND
GND
50
Ω
RF termination
Shown from top without lid; pads shown for better understanding
Pin 0
marker
Figure 6: Minimum configuration A1084-A with Vbak
Remarks:
•
Use separate ground plane for antenna ground.
•
External antenna input impedance is 50
Ω
. Match as close as possible.
•
Maximum allowed external antenna current is 50 mA. Consider a current lim-
iter.
•
A battery back-up circuit for the RTC (Real Time Clock) should be considered
(see chapter: “10.6 Battery Back-up”)
•
Send shutdown command along with a further delay (2s) before switching Vcc
off
