TH71221_15 Datasheet, PDF (38/44 Pages) Melexis Microelectronic Systems – FSK/FM/ASK Transceiver

TH71221
27 to 930MHz
FSK/FM/ASK Transceiver
8 Extended Frequency Range
The operating frequency range of 300 MHz to 930 MHz can be covered without the use of an additional VCO
varactor diode. A frequency range extension down to 27 MHz can be realized by adding an external varactor
diode to the VCO tank.
VCC
RF ^{R01 C01 RB0}
RX_IN
TX_OUT
CB2
RPS
LTX0
CTX4
VD1
C0
L0
CTX0
Combining
network
CRX0
Fig. 18: VCO tank circuit for
extended frequency range
25
OUT_PA
26 IN_LNA
27 VEE_LNA
TH711221
28 OUT_LNA
29 GAIN_LNA
CB6
Lock
detect
SDEN
16
RE/SCLK 15
VCC_DIG 14
SDTA
SCLK
CB7
3wire bus
ASK/FSK 13
VCC
IN_DTA
8.1 Board Component List (Fig. 18)
Part
Size
Value @ Value @ Value @ Value @ Value @
27 MHz 40 MHz 80 MHz 144 MHz 170 MHz
Description
C0
0805
C01
0805
CB2
0603
VD1 SOD-323
CF1
0605
CF2
0605
CTX4 0605
RB0
0605
R01
0805
RF
0805
RF1
0805
RPS
0805
CTX0 0805
CRX0 0805
L0
0805
LTX0
0805
CB6
0805
CB7
0805
fR
NT
NR
LO injection
NIP
1 nF
330 pF
BBY65
1 µF
220 nF
NIP
100 
22 
1.8 k
10 k
15 k
10 nF
10 nF
1.2 µH
2.2 µH
10 nF
100 nF
25 kHz
1080
1508
high
NIP
1 nF
330 pF
BBY65
1 µF
100 nF
33 pF
100 
22 
1.8 k
10 k
15 k
10 nF
10 nF
1.0 µH
330 nH
10 nF
100 nF
25 kHz
1600
2028
high
NIP
68 pF
330 pF
BB639
1µF
100nF
18pF
100 
0
1.8 k
10 k
15 k
10 nF
10 nF
220 nH
220 nH
10 nF
100 nF
25 kHz
3200
2772
low
NIP
100pF
330 pF
BB833
1µF
100 nF
10 pF
100 
0
2.7 k
10 k
22 k
1 nF
1 nF
100 nH
100 nH
1 nF
100 nF
25 kHz
5760
5332
low
NIP
100 pF
330 pF
BB535
1µF
100 nF
8.2 pF
100 
0
390 
10 k
33 k
220 pF
220 pF
47 nH
100 nH
1 nF
100 nF
100 kHz
1700
1807
high
VCO tank capacitor
VCO tank capacitor
de-coupling capacitor
varactor diode
loop filter capacitor
loop filter capacitor
TX impedance matching capacitor
protection resistor
VCO tank resistor
loop filter resistor
loop filter resistor
power-select resistor
TX coupling capacitor
RX coupling capacitor
VCO tank inductor
TX impedance matching inductor
de-coupling capacitor
de-coupling capacitor
frequency resolution
NT counter
NR counter
Note: The component values are optimized for the above listed settings of f_R, NR and NT. Direct VCO modu-
lation as explained in section 3.3.5 must be applied.
39010 071221
Rev. 009
Page 38 of 44
Data Sheet
Nov/15