CMX970Q7

CBUS logic CMX970 CML Microcircuits IF/RF Quadrature COMMUNICATION SEMICONDUCTORS Demodulator D/970/7 February 2015 Provisional Issue Features Applications 20 300 MHz IF/RF Demodulator Wireless Data Terminals 10MHz I/Q Bandwidth HF/VHF and UHF Mobile Radio Serial Bus or Direct Control Operation Avionics Radio Systems Variable Gain and DC Offset Adjustments Low Power 3.0V 3.6V Operation Small 16-lead VQFN Package N/C LO LOGND CBUSOFFN RFGND VSS CSN/ Divide RFIN 2/4 GAIN Gain SCLK/ Gain VCC DIVSET CDATA/ RXIP RESETN RXIN RXQP RXQN VDD 1 Brief Description The CMX970 is a low power IF or RF quadrature demodulator featuring a wide operating frequency range and low power consumption. Suitable for architectures with IF or RF frequencies up to 300MHz the device may be used in low IF systems or those converting down to baseband. Control of the CMX970 may be either by serial bus or by direct control (with reduced functionality). The small, RF-optimised VQFN package and minimal external components make the device ideal for space-constrained applications. 2015 CML Microsystems Plc IF/RF Quadrature Demodulator CMX970 CONTENTS Section Page 1 Brief Description .................................................................................................. 1 2 Block Diagram ...................................................................................................... 4 3 Pin and Signal List ............................................................................................... 5 3.1 Main Functions ................................................................................................ 5 3.2 Direct Control Functions .................................................................................. 5 4 External Components .......................................................................................... 6 4.1 Power Supply Decoupling ................................................................................ 6 4.2 Quadrature Demodulator ................................................................................. 7 4.3 Local Oscillator (LO) Input ............................................................................... 7 5 General Description ............................................................................................. 8 5.1 Programmable Data Interface ......................................................................... 8 5.2 Quadrature Demodulator ................................................................................. 8 5.2.1 I/Q Amplitude and Phase Correction ......................................................... 9 5.2.2 DC Offset Correction ............................................................................... 11 5.3 Local Oscillator (LO) ...................................................................................... 11 6 C-BUS Interface and Register Description ...................................................... 12 6.1 General Reset Command .............................................................................. 13 6.1.1 General Reset Command C-BUS address 1A ...................................... 13 6.2 General Control Register ............................................................................... 13 6.2.1 General Control Register: C-BUS address 1B ...................................... 13 6.3 Control Register ............................................................................................. 14 6.3.1 Control Register: C-BUS address 1C .................................................... 14 6.4 Mode Register ............................................................................................... 15 6.4.1 Mode Register: C-BUS address 1D ...................................................... 15 6.5 Offset Register ............................................................................................... 16 6.5.1 Offset Register: C-BUS address 1F ...................................................... 16 6.6 Intermod Control Register .............................................................................. 17 6.6.1 Intermod Control Register: C-BUS address 2F ..................................... 17 7 Direct Control Option ......................................................................................... 18 8 Application Notes ............................................................................................... 20 8.1 IF/RF Input Matching ..................................................................................... 20 8.2 Receiver Intermodulation and Output Drive Capability .................................. 21 8.3 Receiver Variation with Temperature ............................................................ 22 8.4 Effect of Gain Control on Receiver Performance .......................................... 23 8.5 Measurement of CMX970 Demodulator Intermodulation Performance ........ 25 8.6 Operation with large input signals .................................................................. 26 9 Performance Specification ................................................................................ 27 9.1 Electrical Performance................................................................................... 27 9.1.1 Absolute Maximum Ratings .................................................................... 27 9.1.2 Operating Limits ...................................................................................... 27 9.1.3 Operating Characteristics ........................................................................ 28 9.2 Packaging ...................................................................................................... 32 2015 CML Microsystems Plc 2 D/970/7