Continental Automotive Systems Corporation DMFNA04 Manual De Usuario
Technical aspects of 125 kHz – magnetic field:
Editor :
KN.Kim
Document name
Project code
Version:
1.0
Nov. 14. 2011
ECO / DF No.
Identification No. : Document No.
File:
User Manual for KH_DM_Fob (공통).doc
Page 4 / 6
.
ropri
et
ar
y
dat
a,
c
om
p
any
c
onf
ident
ial
.
A
ll
r
ight
s
res
er
ve
d.
onf
ié
à
t
itr
e
de
s
ec
ret
d'
e
nt
repr
is
e.
T
ous
dr
oi
ts
rés
er
vés
.
ni
c
a
do
c
om
o
segr
edo
em
pr
es
dado
com
o s
ec
ret
o
in
dus
tr
ial
.
.
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
om
u
onf
i
a
ri
al
.
R
N
os
res
e
ser
v
er
v
am
a
dos
t
os
t
o
dos
os
odos
l
os
di
r
derec
e
itos
.
ho
s.
• virtually no reflections,
• cubical decrease of field strength → allows good range control,
• released frequency band (ISM),
• high
• 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.
• 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
-
w
ert
ung
und
M
itt
ei
lung
ihr
es
Inhal
ts
ni
cht
ges
ta
ttet
, s
o
w
ei
t
ni
cht
au
sdr
üc
kl
ic
h
z
uges
tand
en.
Z
uw
ider
handl
un
gen
v
er
-
pf
lic
h
ten
zu S
chadeners
at
z.
A
lle
R
ec
ht
e v
orbehal
te
n
,
ins
be
-
sondere
fü
r den F
a
ll der
a
te
nt
ert
e
ilung oder GM
-E
in
tr
agung
Doors are unlocked automatically
User pulls open the door
L
F
F