TH7122

27 to 930MHz

FSK/FM/ASK Transceiver

39010 07122

Page 2 of 44

Data Sheet

Rev. 008

June/07

Document Content

1

Theory of Operation ...................................................................................................4

1.1

General ............................................................................................................................. 4

1.2

Technical Data Overview.................................................................................................. 4

1.3

Note on ASK Modulation .................................................................................................. 4

1.4

Block Diagram .................................................................................................................. 5

1.5

User Mode Features ......................................................................................................... 5

2

Pin Definitions and Descriptions ..............................................................................6

3

Functional Description ............................................................................................10

3.1

PLL Frequency Synthesizer ........................................................................................... 10

3.1.1

Reference Oscillator (XOSC)..................................................................................................... 11

3.1.2

Reference Divider ...................................................................................................................... 11

3.1.3

Feedback Divider ....................................................................................................................... 11

3.1.4

Frequency Resolution and Operating Frequency ...................................................................... 11

3.1.5

Phase-Frequency Detector ........................................................................................................ 12

3.1.6

Lock Detector ............................................................................................................................. 12

3.1.7

Voltage Controlled Oscillator with external Loop Filter.............................................................. 13

3.1.8

Loop Filter .................................................................................................................................. 13

3.2

Receiver Part .................................................................................................................. 13

3.2.1

LNA ............................................................................................................................................ 14

3.2.2

Mixer .......................................................................................................................................... 14

3.2.3

IF Amplifier ................................................................................................................................. 14

3.2.4

ASK Demodulator ...................................................................................................................... 14

3.2.5

FSK Demodulator ...................................................................................................................... 15

3.3

Transmitter Part .............................................................................................................. 15

3.3.1

Power Amplifier.......................................................................................................................... 15

3.3.2

Output Power Adjustment .......................................................................................................... 16

3.3.3

Modulation Schemes ................................................................................................................. 16

3.3.4

ASK Modulation ......................................................................................................................... 16

3.3.5

FSK Modulation ......................................................................................................................... 17

3.3.6

Crystal Tuning ............................................................................................................................ 17

4

Description of User Modes......................................................................................18

4.1

Stand-alone User Mode Operation ................................................................................. 18

4.1.1

Frequency Selection .................................................................................................................. 18

4.1.2

Operation Mode ......................................................................................................................... 18

4.1.3

Modulation Type ........................................................................................................................ 19

4.1.4

LNA Gain Mode ......................................................................................................................... 19

4.2

Programmable User Mode Operation............................................................................. 19

4.2.1

Serial Control Interface Description ........................................................................................... 19

5

Register Description ................................................................................................20

5.1

Register Overview .......................................................................................................... 21