PIC12F635/PIC16F636/639
FIGURE 11-3:
BIDIRECTIONAL PASSIVE KEYLESS ENTRY (PKE) SYSTEM APPLICATION EXAMPLE
d
e
s
t
e
p
d
y
o
r
C
c
n
E
e
s
)
n
F
o
H
p
U
s
(
e
R
LED
LED
UHF
Transmitter
UHF
Receiver
Ant. X
Ant. Y
Ant. Z
d
n
a
H
m
k
m
5
o
2
C
1
F
(
L
PIC16F639
)
z
MCU
(PIC16F636)
LF
+
Transmitter/
Receiver
3 Input
Analog Front-End
Base Station
Transponder
FIGURE 11-4:
PASSIVE KEYLESS ENTRY (PKE) TRANSPONDER CONFIGURATION EXAMPLE
+3V
315 MHz
VDD
VSS
1
20
19
18
+3V
+3V
S0
S3
2
S1
S4
3
S2
S5
4
17
16
RF Circuitry
LED
Data
5
(UHF TX)
RFEN
CS
6
15
14
13
12
11
LFDATA/RSSI/CCLK/SDIO
SCLK/ALERT
VSST
LCCOM
LCZ
7
+3V
VDDT
LCX
LCY
8
9
10
air-core
coil
ferrite-core
coil
ferrite-core
coil
DS41232D-page 102
© 2007 Microchip Technology Inc.