T5743P3 ATMEL [ATMEL Corporation], T5743P3 Datasheet - Page 6

• Manufacturer Part Number: T5743P3
• Description: UHF ASK/FSK Receiver
• Manufacturer: ATMEL [ATMEL Corporation]

Figure 5. Input Matching Network with SAW Filter
Figure 6. Input Matching Network without SAW Filter
6
RF
f
IN
RF
f
RFIN
RF
= 433.92 MHz
T5743
= 433.92 MHz
8.2p
C2
22p
C3
15p
TOKO LL2012
3.3p
F33NJ
L2
33n
22n
L
25n
TOKO LL2012
2
1
25n
100p
F22NJ
IN
IN_GND
8
9
C16
100p
CASE_GND
Please notify that for all coupling conditions (see Figure 5 and Figure 6), the bond wire
inductivity of the LNA ground is compensated. C3 forms a series resonance circuit
together with the bond wire. L = 25 nH is a feed inductor to establish a DC path. Its
value is not critical but must be large enough not to detune the series resonance circuit.
For cost reduction this inductor can be easily printed on the PCB. This configuration
improves the sensitivity of the receiver by about 1 dB to 2 dB.
8
9
LNAGND
LNA_IN
B3555
3,4 7,8
LNAGND
LNA_IN
T5743
27n
L3
T5743
OUT_GND
TOKO LL2012
F27NJ
C17
8.2p
OUT
6
5
RF
RF
f
f
RF
RF
IN
IN
= 315 MHz
= 315 MHz
33p
10p
C2
47p
C3
3.3p
TOKO LL2012
39n
F82NJ
82n
L2
TOKO LL2012
25n
100p
F39NJ
L
25n
2
1
IN
IN_GND
8
9
8
9
C16
100p
LNAGND
LNA_IN
CASE_GND
LNAGND
LNA_IN
T5743
B3551
3,4 7,8
T5743
47n
L3
OUT_GND
TOKO LL2012
F47NJ
C17
22p
OUT
4569A–RKE–12/02
5
6