your position is our focus
As
long
as
Vcc
is
supplied
to
the
ANTARIS
®
4
GPS
Receiver,
the
backup
battery
is
disconnected
from
the
RTC
and
the
backup
RAM
in
order
to
avoid
unnecessary
battery
drain
(see
Figure 52
).
Power
to
RTC
and
BBR
is
supplied
from
Vcc
in
this
case.
VCC
VBAT
Voltage
Supervisor
GPS Voltage Supply
RTC and Battery Backup RAM (BBR)
J1
Figure 52: Backup Battery and Voltage
Before
Vcc
is
supplied
for
the
first
time,
switch
J1
Figure 52
is
not
initialized.
In
this
case
increased
battery
drain
ight
occur
if
the
backup
battery
is
connected
to
the
V_Bat
pin.
The
battery
drain
will
drop
to
the
specified
level
a
the
first
time.
N
to
connect
the
backup
batter
–
power
up
the
module
for
a
short
time
(e.g.
1s)
ASAP
after
conn
ery
in
order
to
avoid
excessive
battery
4
d current in low
S
pins
RxD1,
to
wake
up
from
FixNOW
sleep
modes.
For
that
reason
ven
if
VCC
is
t
e
internal
pull-up
µA)
flows
through
these
internal
r
.
To
avoid
this
curren
an
order
o
bilities:
•
•
e
receiver
is
in
sle
•
ich
drive
these
pins,
ep
or
backup
mode.
N
ed
off,
a
current
ttery
through
the
pull-up
resistors
XTINT0
a
r
circuit
r).
m
s
soon
as
Vcc
is
applied
ote
It’s
advised
y
while
Vcc
is
on
or
–
if
not
possible
ecting
the
backup
batt
drain.
.2.3 Avoiding increase
power modes
pecial
attention
has
to
be
paid
to
the
RxD2,
EXTINT0
and
EXTINT1.
These
4
pins
can
be
used
these
pins
are
powered
from
backup
supply,
e
urned
off.
Since
these
pins
hav
resistors,
current
(e.g.
15
esistors
if
the
pin
is
driven
low
t,
which
increases
the
sleep
or
backup
currents
by
f
magnitude,
there
are
different
possi
Leave
these
pins
open.
Pull
them
to
a
“HIGH”
while
th
ep
or
backup
mode
Make
sure
the
outputs,
wh
are
in
high-impedance
state
while
the
receiver
is
in
sle
ote
When
the
system
is
turn
may
flow
from
backup
ba
of
these
4
pins
(RxD1,
RxD2,
E
nd
EXTINT1)
through
ESD
protection
diodes
of
you
(i.e.
micro-controlle
GPS
Modules
-
System
Integration
Manual
(SIM)
(incl.
Reference
Design)
Receiver
Description
GPS.G4-MS4-05007-A1
Page 62