ATA3741P3-TGSY Atmel, ATA3741P3-TGSY Datasheet - Page 5

• Manufacturer Part Number: ATA3741P3-TGSY
• Description: RF Receiver ASK/FSK Rem. Ctrl. Rec. (IF= 600 kHz)
• Manufacturer: Atmel
• Type: Receiverr

Specifications of ATA3741P3-TGSY

• Package / Case: SOIC-20
• Operating Frequency: 450 MHz
• Operating Supply Voltage: 5 V
• Maximum Operating Temperature: + 105 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Operating Frequency (max): 450000kHz
• Operating Temperature (min): -40C
• Operating Temperature (max): 105C
• Operating Temperature Classification: Industrial
• Operating Supply Voltage (min): 4.5V
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (max): 5.5V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 3-1.
4899B–RKE–10/06
Conditions
f
f
300 MHz < f
365 MHz < f
RF
RF
= 315 MHz, MODE = 0
= 433.92 MHz, MODE = 1
RF
RF
Calculation of LO and IF Frequency
< 365 MHz, MODE = 0
< 450 MHz, MODE = 1
f
mula:
To determine f
frequency is f
is tuned by the crystal frequency f
f
The relation is designed to achieve the nominal IF frequency of f
tions. For applications where f
f
f
ferent conditions.
The RF input either from an antenna or from a generator must be transformed to the RF input
pin LNA_IN. The input impedance of LNA_IN is specified in
23. The parasitic board inductances and capacitances also influence the input matching. The RF
receiver ATA3741 exhibits its highest sensitivity at the best signal-to-noise ratio in the LNA.
Hence, noise matching is the best choice for designing the transformation network.
A good practice when designing the network is to start with power matching. From that starting
point, the values of the components can be varied to some extent to achieve the best sensitivity.
If a SAW is implemented into the input network, a mirror frequency suppression of P
can be achieved. There are SAWs available that exhibit a notch at f = 2 MHz. These SAWs
work best for an intermediate frequency of IF = 1 MHz. The selectivity of the receiver is also
improved by using a SAW. In typical automotive applications, a SAW is used.
Figure 3-2 on page 6
f
out a SAW. The input matching networks shown in
parameters given in the
f
MODE
MODE
LO
LO
RF
IF
RF
LO
is then dependent on the logical level at pin MODE and on f
that depends on the logic level at pin mode. This is described by the following formulas:
= 433.92 MHz, MODE must be set to ”1”. For other RF frequencies, f
= 433.92 MHz using a SAW.
is determined by the RF input frequency f
=
f
RF
=
=
–
0 (USA) f
1 (Europe) f
f
IF
IF
Local Oscillator Frequency
f
f
f
f
LO
LO
LO
LO
LO
= 1 MHz. To achieve a good accuracy of the filter’s corner frequencies, the filter
, the construction of the IF filter must be considered at this point. The nominal IF
= 314 MHz
= 432.92 MHz
=
=
IF
-------------------
1
--------------------------- -
1
=
IF
+
+
f
--------- -
314
RF
f
=
--------- -
314
----------------- -
432.92
f
LO
RF
“Electrical Characteristics” on page
1
shows a typical input matching network for f
----------------- -
432.92
1
f
LO
Figure 3-3 on page 6
RF
XTO
= 315 MHz, MODE must be set to “0”. In the case of
. This means that there is a fixed relation between f
RF
and the IF frequency f
Figure 3-3
Intermediate Frequency
f
f
f
IF
IF
IF
illustrates an input matching to 50 with-
f
= 1 MHz
= 1 MHz
IF
=
=
----------------- -
432.92
f
23.
--------- -
314
f
LO
“Electrical Characteristics” on page
LO
are the reference networks for the
RF
.
Table 3-1
IF
= 1 MHz for most applica-
IF
IF
using the following for-
is not equal to 1 MHz.
RF
summarizes the dif-
= 315 MHz and
ATA3741
Ref
= 40 dB
IF
and
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