EVB72035

868/915MHz FSK/ASK Transmitter

Evaluation Board Description

39012 72035 01

Page 7 of 14

EVB Description

Rev. 007

June/07

5 6

4

23

1

12 34 56

RPS

CB0

CX2

XTAL

CX1

2

3

4

5

1

9

8

76

10

CK

PCB loop antenna

CM2

CM1

CB1

3

Antenna Board Circuit Diagram

Fig. 6:

Circuit diagram with loop antenna matching network

3.1

Board Component Values to Fig. 6

Part

Size

Value @

868.3 MHz

Value @

915 MHz

Toler-

ance

Description

CM1

0603

4.7 pF

3.9 pF

±5%

impedance matching capacitor

CM2

0603

3.3 pF

3.3 pF

±5%

impedance matching capacitor

LM1

0603

27 nH

27 nH

±5%

impedance matching inductor

LM2

0603

12 nH

10 nH

±5%

impedance matching inductor

0805

18 pF

18 pF

±5%

XOSC FSK capacitor (

Δf = ±20 kHz), note 1

0805

27 pF

27 pF

±5%

CX2

0805

10 pF

10 pF

±5%

XOSC capacitor (

Δf = ±20 kHz), note 1,

only needed for FSK

RPS

0603

NIP

±5%

power-select resistor, see data sheet section 4.6

CB0

1206

220 nF

±10%

de-coupling capacitor

CB1

0603

330 pF

±10%

de-coupling capacitor

27.13438 MHz 28.59375 MHz

XTAL

HC49/S

±30ppm cal.; ±30ppm temp.

fundamental wave crystal,

CK

0805

1 nF

±10%

ROI coupling capacitor, only required for

external reference frequency input

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