Datasheet

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