CMX972 Datasheet, PDF (3/41 Pages) CML Microcircuits – Small 32-lead VQFN Package

Quadrature Demodulator with IF PLL/VCO
CMX972
CONTENTS
Section
Page
1
Brief Description .................................................................................................. 2
1.1 History.............................................................................................................. 5
2
Block Diagram ...................................................................................................... 6
3
Pin List .................................................................................................................. 7
4
External Components .......................................................................................... 8
4.1 Power Supply Decoupling ................................................................................ 8
4.2 Quadrature Demodulator ................................................................................. 9
4.3 Local Oscillator (LO) Input ............................................................................... 9
4.4 VCO and PLL................................................................................................... 9
4.5 Differential Amplifiers..................................................................................... 12
4.5.1 I/Q Output Amplifiers ............................................................................... 12
4.5.2 Low IF Output.......................................................................................... 13
5
General Description ........................................................................................... 14
5.1 Quadrature Demodulator ............................................................................... 14
5.1.1 I/Q Amplitude and Phase Correction....................................................... 14
5.1.2 DC Offset Correction ............................................................................... 16
5.2 Differential Amplifiers..................................................................................... 17
5.3 Local Oscillator (LO) ...................................................................................... 17
5.3.1 Demodulator LO Input ............................................................................. 17
5.3.2 VCO and PLL .......................................................................................... 17
6
C-BUS Interface and Register Description ...................................................... 20
6.1 General Reset Command .............................................................................. 21
6.1.1 General Reset Command - $1A: no data................................................ 21
6.2 General Control Register ............................................................................... 22
6.2.1 General Control Register - $1B: 8-bit write ............................................. 22
6.2.2 General Control Register - $EB: 8-bit read ............................................. 22
6.3 Rx Control Register ....................................................................................... 22
6.3.1 Rx Control Register - $1C: 8-bit write...................................................... 22
6.3.2 Rx Control Register - $EC: 8-bit read ..................................................... 23
6.4 Rx Mode Register .......................................................................................... 23
6.4.1 Rx Mode Register - $1D: 8-bit write ........................................................ 23
6.4.2 Rx Mode Register - $ED: 8-bit read ........................................................ 24
6.5 Rx Offset Register ......................................................................................... 24
6.5.1 Rx Offset Register - $1F: 8-bit write........................................................ 24
6.5.2 Rx Offset Register - $EF: 8-bit read........................................................ 25
6.6 PLL M Divider Register .................................................................................. 25
6.6.1 PLL M Divider - $2C - $2A: 8-bit write ..................................................... 25
6.6.2 PLL M Divider - $DC - $DA: 8-bit read .................................................... 26
6.7 PLL R Divider Register .................................................................................. 26
6.7.1 PLL R Divider - $2E - $2D: 8-bit write ..................................................... 26
6.7.2 PLL R Divider - $DE - $DD: 8-bit read .................................................... 26
6.8 VCO Control Register .................................................................................... 26
6.8.1 VCO Control Register - $2F: 8-bit write................................................... 26
6.8.2 VCO Control Register - $DF: 8-bit read .................................................. 27
7
Application Notes ............................................................................................... 28
7.1 IF/RF Input Matching ..................................................................................... 28
 2015 CML Microsystems Plc
3
D/972/2