ATA5428-PLSW80 Atmel, ATA5428-PLSW80 Datasheet - Page 7

• Manufacturer Part Number: ATA5428-PLSW80
• Description: RF Transceiver ASK/FSK Transceiver 434 and 868MHz
• Manufacturer: Atmel

Specifications of ATA5428-PLSW80

• Wireless Frequency: 226 KHz, 237 KHz
• Interface Type: 4-Wire SPI
• Noise Figure: 7 dB
• Output Power: 10 dBm
• Operating Supply Voltage: 2.4 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: QFN-48
• Maximum Data Rate: 20 Kbps
• Minimum Operating Temperature: - 40 C
• Modulation: ASK, FSK
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

2. Application Circuits
2.1
Figure 2-1.
4841D–WIRE–10/07
Typical Remote Control Unit Application with 1 Li Battery (3V)
Loop antenna
Typical Remote Control Unit Application, 433.92 MHz, 1 Li Battery (3V)
AVCC
C
10
L
2
L
1
Figure 2-1
external components are 11 capacitors, 1 resistor, 2 inductors and a crystal. C
voltage supply blocking capacitors. C
capacitor used for the internal quasi-peak detector and for the high-pass frequency of the data
filter. C
tor of about 5.6 nH to 56 nH. L
the crystal is integrated. R
loop antenna’s quality factor is somewhat reduced by this application due to the quality factor of
L
robust design with a bandwidth that is broad enough for production tolerances. Due to the sin-
gle-ended and ground-referenced design, the loop antenna can be a free-form wire around the
application as it is usually employed in remote control uni-directional systems. The
ATA5423/ATA5425/ATA5428/ATA5429 provides sufficient isolation and robust pulling behavior
of internal circuits from the supply voltage as well as an integrated VCO inductor to allow this.
Since the efficiency of a loop antenna is proportional to the square of the surrounded area it is
beneficial to have a large loop around the application board with a lower quality factor in order to
relax the tolerance specification of the RF components and to get a high antenna efficiency in
spite of their lower quality factor.
2
C
and the RX/TX switch. On the other hand, this lower quality factor is necessary to have a
5
C
C
C
7
8
9
11
to C
R
1
shows a typical 433.92 MHz Remote Control Unit application with one battery. The
11
are RF matching capacitors in the range of 1 pF to 33 pF. L1 is a matching induc-
C
NC
NC
NC
RF_IN
NC
433_N868
NC
R_PWR
PWR_H
RF_OUT
NC
NC
7
ATA5423/ATA5425/ATA5428/ATA5429
C
C
1
2
ATA5423/ATA5425
ATA5428/ATA5429
1
is typically 22 k and sets the output power to about 5.5 dBm. The
+ Lithium cell
2
is a feed inductor of about 120 nH. A load capacitor of 9 pF for
5
C
is a 10 nF supply blocking capacitor. C
4
SDO_TMDO
DEM_OUT
SDI_TMDI
N_RESET
CDEM
VSINT
RSSI
SCK
CLK
IRQ
NC
CS
C
13.25311 MHz
6
XTAL2
C
3
VCC
48/88/168
ATmega
Sensor
VSS
6
1
is a 15 nF fixed
to C
4
are 68 nF
7