ATA5824-PLQW Atmel, ATA5824-PLQW Datasheet - Page 18

• Manufacturer Part Number: ATA5824-PLQW
• Description: IC TXRX UHF ASK/FSK 48QFN
• Manufacturer: Atmel

Specifications of ATA5824-PLQW

• Frequency: 433 ~ 435MHz; 866 ~ 870MHz
• Data Rate - Maximum: 20kbps
• Modulation Or Protocol: ASK, FSK
• Applications: RKE, TPM, Security Systems
• Power - Output: 10dBm
• Sensitivity: -116dBm
• Voltage - Supply: 2.15 V ~ 3.6 V or 4.4 V ~ 5.25 V
• Current - Receiving: 10.5mA
• Current - Transmitting: 10.5mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Operating Temperature: -40°C ~ 105°C
• Package / Case: 48-VQFN Exposed Pad, 48-HVQFN, 48-SQFN, 48-DHVQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Memory Size: -

7.10
7.11
18
RSSI Output
Frequency Synthesizer and Channel Selection
ATA5823/ATA5824
The output voltage of the pin RSSI is an analog voltage, proportional to the input power level.
Using the RSSI output signal, the signal strength of different transmitters can be distinguished.
The usable dynamic range of the RSSI amplifier is 70 dB, the input power range P
–
teristic of a typical device at 433.92 MHz with V
+105°C with a matched input according to
868.3 MHz about 2.7 dB more signal level and at 315 MHz about 1 dB less signal level is
needed for the same RSSI results.
Figure 7-8.
The synthesizer is a fully integrated fractional-N design with internal loop filters for receive and
transmit mode. The XTO frequency f
The bits FR0 to FR12 in control registers 2 and 3 (see
on page
433.92 MHz, the carrier has a phase noise of
–
20 Kbit/s Manchester data. Due to the closed loop modulation, any spurious caused by this
modulation are effectively filtered out as can be seen in
synthesizer has a phase noise of
The initial tolerances of the crystal oscillator due to crystal frequency tolerances, internal capac-
itor tolerances and the parasitics of the board have to be compensated at manufacturing setup
with control registers 2 and 3 as can be seen in
for the synthesizer needed for ASK, FSK and receive/transmit switching are calculated inter-
nally. The RF (Radio Frequency) resolution is equal to the XTO frequency divided by 16384
which is 777.1 Hz at 315.0 MHz, 808.9 Hz at 433.92 MHz and 818.59 Hz at 868.3 MHz.
The frequency control word FREQ in control registers 2 and 3 can be programmed in the range
of 1000 to 6900, hence every frequency within the 433 MHz and 868 MHz ISM bands can be
programmed as receive and as transmit frequency and the position of channels within these ISM
bands can be chosen arbitrarily (see
115 dBm to
70 dBC with a high PLL loop bandwidth allowing the direct modulation of the carrier with
39) are used to adjust the deviation of f
–
45 dBm and the gain is 8 mV/dB.
Typical RSSI Characteristic at 433.92 MHz versus Temperature and Supply
Voltage
1100
1000
900
800
700
600
500
400
-120
-110
–
min.
120 dBC/Hz at 1 MHz and spurious of
-100
Table 9-1 on page
XTO
is the reference frequency FREF for the synthesizer.
Table 7-2 on page 12
-90
P
RF_IN
typ.
–
111 dBC/Hz at 1 MHz and spurious at FREF of
Figure 7-8 on page 18
Table 9-1 on page
S1
-80
(dBm)
= V
XTO
S2
Table 12-7 on page 38
Figure 7-11 on page
-70
30).
= 2.15V to 3.6V and T
. In half-duplex transmit mode, at
max.
-60
and
30. The other control words
-50
Figure 7-1 on page
shows the RSSI charac-
–
-40
72 dBC.
20. In RX mode the
and
amb
4829D–RKE–06/06
Table 12-10
=
–
40°C to
RFIN
11. At
is