ATA5428-PLQW80 Atmel, ATA5428-PLQW80 Datasheet - Page 11

• Manufacturer Part Number: ATA5428-PLQW80
• Description: RF Transceiver ASK/FSK Transceiver 434 and 868MHz
• Manufacturer: Atmel

Specifications of ATA5428-PLQW80

• 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

3.2
4841D–WIRE–10/07
Input Matching at RF_IN
A low-IF architecture is also less sensitive to second-order intermodulation (IIP2) than direct
conversion receivers, where every pulse or AM-modulated signal (especially the signals from
TDMA systems like GSM) demodulates to the receiving signal band at second-order
non-linearities.
Note:
The measured input impedances as well as the values of a parallel equivalent circuit of these
impedances can be seen in
of these impedances to the source impedance of 50
Table 3-1.
The matching of the LNA Input to 50 was done with the circuit shown in
values given in
value changes of C
measured typical FSK and ASK Manchester code sensitivities with a Bit Error Rate (BER) of 10
are shown in
tors having a quality factor according to
0.8 dB at 315 MHz, 0.8 dB at 345 MHz, 0.7 dB at 433.92 MHz, 0.7 dB at 868.3 MHz and 0.7 at
915 MHz. These losses can be estimated when calculating the parallel equivalent resistance of
the inductor with R
With an ideal inductor, for example, the sensitivity at 433.92 MHz/FSK/20 Kbit/s/
±16 kHz/Manchester can be improved from –106 dBm to –106.7 dBm. The sensitivity depends
on the control logic which examines the incoming data stream. The examination limits must be
programmed in control registers 5 and 6. The measurements in
page 12
Figure 3-1.
–
are based on the values of registers 5 and 6 according to
120 dBC/Hz at ±1 MHz and
f
433.92
RF
868.3
Table 3-3
315
345
915
/MHz
Measured Input Impedances of the RF_IN Pin
Input Matching to 50
Table 3-2 on page
loss
1
and L
= 2
ATA5423/ATA5425/ATA5428/ATA5429
and
1
Table 3-4 on page
may be necessary to compensate for individual board layouts. The
Table
f
–
12. The reflection coefficients were always 10 dB. Note that
3-1. The highest sensitivity is achieved with power matching
75 dBC at ±FREF at 433.92 MHz
L
C
1
Q
L
(44
(40
(32
Z(RF_IN)
Table
(21
(18
L
1
and the matching loss with 10 log(1 + R
-
-
-
-
-
j233)
j211)
j169)
j78)
j70)
12. These measurements were done with induc-
3-2, resulting in estimated matching losses of
4
ATA5423/ATA5425
ATA5428/ATA5429
RF_IN
Table 9-3 on page
Table 3-3
1278 //2.1 pF
1153 //2.1 pF
Figure 3-1
925 //2.1 pF
311 //2.2 pF
290 //2.3 pF
R
p
and
//C
p
Table 3-4 on
p
and with the
/R
61.
loss
).
11
-3