TH71111 Datasheet, PDF (16/22 Pages) Melexis Microelectronic Systems – 868/915MHz FSK/FM/ASK Receiver

4.3 FM Reception (Varactor-tuned AFC)
4.3.1 FM Application Circuit
TH71111
868/915MHz
FSK/FM/ASK Receiver
OUTP _FM OUTN
RSSI
C14
C16 C17 _C18
R3
R4
R5
VCC
CP VD
XTAL
25 VEE
C1
26 RO
VCC
27 VCC
ENRX
R1
28 ENRX
C3
29 LF
30 VEE
TH71111
16
C12
OUT_IFA 15
CERDIS
VCC 14
FBC2 13
FBC1 12
IN_IFA 11
VCC
C11
C9
R2 ^C10
31 IN_LNA
VEE 10
C5
L2
32 VCC
VCC
OUT_MIX2 9
123 456 78
CERFIL
64
C7
1 3 ^SAWFIL
L1
C4
50
RF input
L3
CB*
VCC
* each Vcc pin with blocking cap of 330pF
* one global Vcc blocking cap of 33nF
Fig. 4: Test circuit for FM reception
Circuit Features
• Tolerates input frequency variations
• Applicable for FM
39010 71111
Rev. 013
Page 16 of 22
Data Sheet
June/07