Editor :
KN.Kim
Document name
Project code
Version:
1.0
Nov. 14. 2011
ECO / DF No.
Identification No. : Document No.
File:
User Manual for MD FL_Fob_FCC
매뉴얼용
Page 4 / 6
.
P
ropri
e
ta
ry
dat
a,
c
o
m
p
any
c
onf
ident
ia
l.
A
ll
r
ight
s
res
e
rv
e
d
.
C
onf
ié
à
t
itr
e
de
s
e
c
ret
d'
e
n
tr
epr
is
e.
T
ous
dr
oi
ts
rés
e
rv
és
.
C
o
m
u
ni
c
a
do
c
o
m
o
segr
edo
em
pr
es
a
ri
a
l.
R
e
se
rv
ados
t
odos
os
di
re
itos
.
C
onf
idado
co
m
o
s
e
cr
et
o
in
dus
tr
ia
l.
N
o
s
res
e
rv
am
os
t
odos
l
o
s derec
ho
s.
.
W
e
iterga
be s
o
w
ie V
er
vi
e
lfäl
tigung di
es
er U
n
te
rl
ag
e,
V
e
r-
w
e
rt
ung
und
M
itt
ei
lung
ih
re
s
Inhal
ts
ni
ch
t ges
ta
ttet
, s
o
w
e
it
ni
ch
t
au
sd
rü
ck
lic
h
z
uges
tand
en.
Z
u
w
ider
handl
un
gen
v
e
r-
pf
lic
h
ten
zu
S
chadeners
a
tz
.
A
lle
R
e
ch
te
v
o
rbehal
te
n
,
in
sb
e
-
sondere
fü
r den F
a
ll der
P
a
te
nt
ert
e
ilung oder GM
-E
in
tr
agung
Technical aspects of 125 kHz – magnetic field:
virtually no reflections,
cubical decrease of field strength
allows good range control,
released frequency band (ISM),
high
penetration,
low quiescent current demand due to 125 kHz input stage (SMART KEY FOB),
less sensitive for detuning compared to higher frequency.
For the down-link from the SMART KEY FOB to the vehicle, the standard radio frequency
(RF) is used (similar to the classic remote control functions) with FSK modulation.
1.3 System
Overview
Figure 1: Principle of Communication
ECU sends LF challenge via exterior antenna
ID tag sends identification code to RF receiver
Doors are unlocked automatically
User pulls open the door
L
F
