ATA5823 ATMEL Corporation, ATA5823 Datasheet - Page 9

• Manufacturer Part Number: ATA5823
• Description: Uhf Ask/fsk Transceiver Ata5823 Ata5824
• Manufacturer: ATMEL Corporation

6. Typical Car Application for Full-duplex PEG
Figure 6-1.
4829D–RKE–06/06
Typical Car Application for Full-duplex PEG, 433.92 MHz
connector to
RX antenna
(located in the control unit)
RFIN
50
L
TX Loop antenna
2
C
8
AVCC
SAW filter
Figure 6-1
components are 11 capacitors, 1 resistor, 3 inductors, a SAW Filter and a crystal. C
are 68 nF voltage supply blocking capacitors. C
internal voltage regulator. C5 is a 10 nF supply blocking capacitor. C
used for the internal quasi-peak detector and for the high-pass frequency of the data filter. C
C
120 nH, L
RF_IN. A load capacitor of 9 pF for the crystal is integrated. C
necessary to prevent that signals couple into the pin R_PWR, causing amplitude modulation of
the output power and a spurious rise of the transmitted signal. R
close to the R_PWR pin. R
power of 0 dBm in full-duplex mode and 5 dBm in half-duplex mode. The quality factor of the
TX-loop antenna is only reduced by the quality factor of L
important. Since the 2 Antennas are located at different places the isolation between RF_OUT
and RF_IN is about 45 dB and the coupled output power from RF_OUT to RF_IN is about
–
RF power at RF_IN to
ters in the full-duplex system is unsuitable due to the high group delay which desensitize the
receiver.
45 dBm. The receive Sensitivity in full-duplex mode is reduced from
10
C
are RF matching capacitors in the range of 1 pF to 33 pF. L
C
10
L
9
1
2
L
3
shows a typical 433.92 MHz V
C
and L
C
5
7
R
C
1
3
11
are matching inductors to match the RX-antenna to the SAW and the SAW to
NC
NC
NC
RF_IN
NC
433_N868
NC
R_PWR
PWR_H
RF_OUT
NC
NC
–
102 dBm with
1
ATA5823/ATA5824
is typically 22 k and SETPWR is programmed to get an output
C
1
C
V
2
CC
–
45 dBm coupled RF power at RF_IN. The use of SAW fil-
= 4.4 V ... 5.25 V
CC
C
= 4.4V to 5.25V PEG car application. The external
4
SDO_TMDO
SDI_TMDI
2
is a 2.2 µF supply blocking capacitors for the
TEST3
CDEM
VSINT
POUT
RSSI
SCK
CLK
IRQ
NC
CS
C
XTAL2
6
1
, the tolerances of C
ATA5823/ATA5824
11
13.25311 MHz
is a 10 nF capacitor which is
1
C
VCC
1
is a feed inductor of about
3
Microcontroller
6
and C
–
is a 15 nF fixed capacitor
106 dBm without coupled
11
V
SS
9
should be placed
and C
1
, C
10
3
are thus
and C
7
to
9
4