EVB72015
433MHz FSK/ASK Transmitter
Evaluation Board Description
3 Antenna Board Circuit Diagram
PCB loop antenna
CM2
CB1
CM1
10
9
8
7
6
RPS
2
3
4
5
1
CX2
XTAL
CX1
CK
CB0
1
2
3
4
5 6
6
5
4
1
2 3
Fig. 6: Circuit diagram with loop antenna matching network
3.1 Board Component Values to Fig. 6
Value
@ 433.92 MHz
Part
Size
Tolerance
Description
CM1
CM2
0603
0603
0603
0603
0805
0805
0805
0603
1206
0603
HC49/S
18 pF
3.3 pF
27 nH
68 nH
12 pF
27 pF
33 pF
NIP
impedance matching capacitor
±5%
±5%
±5%
±5%
±5%
±5%
±5%
±5%
±20%
±10%
impedance matching capacitor
impedance matching inductor
impedance matching inductor
LM1
LM2
CX1_FSK
CX1_ASK
CX2
XOSC FSK capacitor (Δf = ±28 kHz), note 1
XOSC ASK capacitor, trimmed to fC, note 1
XOSC capacitor (Δf = ±28 kHz), note 1, only needed for FSK
power-select resistor, see data sheet section 4.6
de-coupling capacitor
RPS
CB0
220 nF
330 pF
CB1
de-coupling capacitor
XTAL
13.5600 MHz
±30ppm cal., ±30ppm temp.
1 nF
fundamental-mode crystal,
CL = 12 pF, C0, max = 7 pF, R1 = 60 Ω
CK
0805
ROI coupling capacitor,
only required for external reference frequency input
±10%
Note 1: depends on crystal parameters, other ∆f values can be selected with other CX1, CX2 values
NIP – not in place, may be used optionally
39012 72015 01
Rev. 007
Page 7 of 14
EVB Description
June/07
MELEXIS [ Melexis Microelectronic Systems ]
