TH72036

868/915MHz

FSK/ASK Transmitter

Page 13 of 16

REVISION 010 - JUNE 14, 2017

3901072036

5. Test Circuit

5.1. Test circuit component list to Fig. 6

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

22 pF

22 pF

5%

XOSC FSK capacitor (f = 20 kHz), note 1

0805

27 pF

27 pF

5%

CX2

0805

12 pF

12 pF

5%

XOSC capacitor (f = 20 kHz), note 1

only needed for FSK

CCK

0805

15 pF / 180 pF

5%

clock spur suppression capacitor, CKDIV 0 / 1

RPS

0805

see section 4.6

5%

FSK or CW mode power-select resistor

R1

see section 4.7

ASK power-select resistor, not used at FSK

CB0

0805

220 nF

20%

de-coupling capacitor

CB1

0805

330 pF

10%

de-coupling capacitor

XTAL

SMD

6x3.5

27.13438 MHz

28.59375 MHz

30ppm calibr.

30ppm temp.

fundamental wave crystal,

CL = 12 pF, C0, max = 7 pF, R1 = 40 

Note 1: value depending on crystal parameters

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

CB1

CM1

CM2

OUT

CM3

LM

LT

RPS

CB0

2 3

1

2

1

2

1

6

7

8

9

10

R1

CX1

5

4

3

1

2

2

1

2

1

2

1