TH72035

868/915MHz

FSK/ASK Transmitter

39010 72035

Page 17 of 20

Data Sheet

Rev. 008

June/07

6

Test Circuit

Fig. 18: Test circuit for FSK and ASK with 50

Ω matching network

6.1

Test circuit component list to Fig. 18

Part

Size

Value @

868.3 MHz

Value @

915 MHz

Tolerance

Description

CM1

0805

1.8 pF

2.2 pF

±5%

impedance matching capacitor

CM2

0805

5.6 pF

5.6 pF

±5%

impedance matching capacitor

CM3

0805

68 pF

68 pF

±5%

impedance matching capacitor

LM

0805

12 nH

10 nH

±5%

impedance matching inductor, note 2

LT

0805

15 nH

10 nH

±5%

output tank inductor, note 2

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

0805

see section 4.6

±5%

power-select resistor

CB0

0805

220 nF

±20%

de-coupling capacitor

CB1

0805

330 pF

±10%

de-coupling capacitor

XTAL

HC49/S

27.13438 MHz

28.59375 MHz

±30ppm calibr.

±30ppm temp.

fundamental wave crystal,

Note 1: value depending on crystal parameters

Note 2: for high-power applications high-Q wire-wound inductors should be used

RPS

CB1

CM1

CM2

OUT

CM3

LM

LT

CB0

2 3

1

2 3 4

1

2

1

CX2

XTAL

CX1

6

7

8

9

10

5

4

3

12