Direct Conversion Receivers

CMX994/CMX994A/CMX994E

 2015 CML Microsystems Plc

D/994_A_E/1

Page 3 of 70

7.8.1

PLL R Divider - $24 - $23 – 8-bit write only.....................................................................................................34

7.8.2

PLL R Divider - $D4-$D3 – 8-bit read only.......................................................................................................34

7.9

VCO Control Register ......................................................................................................................................35

7.9.1

VCO Control - $25 - 8-bit write only................................................................................................................35

7.9.2

VCO Control - $D5 - 8-bit read only ................................................................................................................35

8

Application Notes.................................................................................................................................... 36

8.1

Typical Receiver Performance ........................................................................................................................36

8.1.1

System Performance.......................................................................................................................................36

8.1.2

DC Offsets .......................................................................................................................................................37

8.1.3

Gain Control....................................................................................................................................................38

8.1.4

LNA Intermodulation Optimisation ................................................................................................................41

8.1.5

Low Power Mode............................................................................................................................................42

8.1.6

I/Q Filter Response .........................................................................................................................................42

8.1.7

Baseband Intermodulation .............................................................................................................................43

8.1.8

LO Pulling ........................................................................................................................................................43

8.1.9

Rx Mixer Output (Broadband Operation) .......................................................................................................44

8.1.10

Spurious Responses ........................................................................................................................................45

8.2

Operation Below 100MHz...............................................................................................................................46

8.3

Transmitter LO Output....................................................................................................................................46

8.4

Modem Solutions............................................................................................................................................48

9

Performance Specification....................................................................................................................... 50

9.1

Electrical Performance....................................................................................................................................50

9.1.1

Absolute Maximum Ratings ............................................................................................................................50

9.1.2

Operating Limits..............................................................................................................................................50

9.2.1

Operating Characteristics ...............................................................................................................................51

AC Parameters – Direct Conversion Receiver Sections....................................................................................54

AC Parameters – Tx Output.............................................................................................................................58

AC Parameters – C-BUS...................................................................................................................................59

9.3

Packaging ........................................................................................................................................................60