Product Preview PP973/1 June 2012 CMX973 Quadrature Modulator/Demodulator (RF Building Block) Introduction CMX973 Brief Description The CMX973 Quadrature Modulator/Demodulator is a new addition to the CML RF Building Block product range, where low power consumption, flexibility and high performance are key values . The CMX973 integrates a quadrature (I/Q) modulator and a low-power quadrature IF/RF demodulator, both featuring a wide operating frequency range and optimised power consumption. The CMX973 Quadrature Modulator/Demodulator offers very low power consumption and high performance over a wide operating range. The CMX973 forms the basis of a high-performance RF transceiver system combining a flexible IF/RF quadrature modulator and quadrature demodulator, in one chip. Wide signal bandwidth at RF, 0dBm output, low noise and serial bus control, delivers maximum flexibility and high performance, all at an attractive low operating power. The demodulator is suitable for superheterodyne architectures with IF frequencies up to 300MHz and the device may be used in low IF systems or those converting down to baseband. The modulator converts directly from baseband to the desired transmit frequency and features quadrature phase correction to minimise unwanted spectral components. An on-chip PLL and VCO, together with uncommitted baseband differential amplifiers, provide additional flexibility. Control of the CMX973 is by serial bus. The CMX973 is supplied in an RF-optimised 32-lead VQFN package. Features Key benefits Size is an important factor in many radio designs, the CMX973 addresses this with its availability in a very small, RF optimised 32-pin VQFN package (5mm x 5mm x 1mm). TXIN Applications Flexible RF Building Block solution Low power consumption High performance Flexibility Low noise Small VQFN packaging Simple interfacing to existing modem/ baseband products RXLO VCO P2 VCO P1 VCO N1 VCO N2 OA1O OA1P VCO 40-500MHz TXQP VSS Quadrature modulator TXQN 32-pin VQFN (5mm x 5mm x 1mm) CSN RFOUT OA2O Local oscillator switching IFIN OA2N VCC OA2P Quadrature demodulator RXIN PLL RXIP RXQP RXQN TXLO REFIN DO Serial bus and control VCC CDATA SYNTH CMX973 Function Diagram © 2012 CML Microsystems Plc OA1N TXIP Wireless data terminals HF, VHF and UHF mobile radio Avionics radio systems Telemetry modems High-performance professional radios Satellite terminals Software Defined Radio (SDR) 20MHz - 300MHz IF/RF demodulator 20MHz - 1GHz RF modulator I/Q bandwidth: 10MHz Rx and 25MHz Tx 0dBm modulator output level < 1degree I/Q phase matching < 0.5dB I/Q gain matching Serial bus control Low-power operation 3.0V - 3.6V Very small 32-lead Package 1 VDD RDATA SCLK CMX973 Quadrature Modulator/Demodulator Product Preview Quadrature Modulation Quadrature (I/Q) modulation provides a number of advantages over conventional two-point modulation schemes. Two-point modulation requires calibration/adjustment to achieve optimum performance. I/Q modulation is the answer, providing maximum flexibility in the digital domain and allowing coherent phase to be achieved. An I/Q modulator provides accurate phase modulation. I/Q baseband signals are mixed up to RF by two double-balanced mixers driven by the same frequency but separated in phase by 90 degrees. The outputs of the two mixers are then summed to provide the modulated output. Quadrature Demodulation The quadrature demodulator is designed for IF/RF operation and has very low power consumption. Input frequencies in the range 20 to 300 MHz are allowed. The demodulator system has two gain stages, one before and one after the I/Q down-converters and the gain elements can be independently controlled. This flexible architecture allows users to optimise characteristics depending on their system requirements. Optimum noise figure can be achieved by maximising the gain in first gain stage and minimising gain in the second stage. Intermodulation performance can be optimised by decreasing gain in the first or second stages. A lower gain in the second gain stage will tend to reduce dc offsets in the output I/Q signal. Further detailed information on the effects of controlling gain stages is available in the CMX973 datasheet. Typical system application using: CMX973—Quadrature Modulator/Demodulator CMX7861—Programmable Baseband Interface IC © 2012 CML Microsystems Plc 2 CMX973 Quadrature Modulator/Demodulator Product Preview Evaluation Support The EV9730 is an Evaluation Kit designed for evaluating and demonstrating the capabilities of the CMX973 integrated circuit. All the circuits necessary to demonstrate the facilities provided by the IC, such as matching circuits, power supply regulators, etc. are provided on the EV9730 board. A C-BUS serial interface connector is provided for control of the EV9730 by a host microcontroller or CML PE0002 interface card. Alternatively any microcontroller evaluation/emulator kit can be used to drive the CMX973/EV9730 serial bus. Package DIM. * * MIN. A B C F G H J K L L1 P T TYP. MAX. 5.00 BSC 0.80 3.00 3.00 0.00 0.18 0.20 0.30 0 5.00 BSC 0.90 0.25 1.00 3.80 3.80 0.05 0.30 0.55 0.15 0.50 0.20 NOTE : * Exposed Metal Pad A & B are reference data and do not include mold deflash or protrusions. All dimensions in mm Angles are in degrees Index Area 1 Dot Index Area 2 Dot Chamfer Index Area 1 is located directly above Index Area 2 Depending on the method of lead termination at the edge of the package, pull back (L1) may be present. L minus L1 to be equal to, or greater than 0.3mm The underside of the package has an exposed metal pad which should ideally be soldered to the pcb to enhance the thermal conductivity and mechanical strength of the package fixing. Where advised, an electrical connection to this metal pad may also be required Mechanical Outline of the 32-pin VQFN (Q5) © 2012 CML Microsystems Plc 3 CMX973 Quadrature Modulator/Demodulator Product Preview Electrical Specification Summary Operating Limits Min Typ Max Unit 3.0 3.0 - 3.6 3.6 V V -40 40 20 - +85 2000 1000 °C MHz MHz Min Typ Max Unit - 7 1.7 63 15 - µA mA mA mA Quadrature Modulator Min Typ Max Unit Performance Figures: Output Power (PEP) Noise Floor Equivalent Output IP3 - 0 -150 21 - dBm dBm/Hz dBm Min Typ Max Unit - 56 10 - dB(V/V) dB - -15 - dBm Supply Voltage: Digital Supply (VDD – VSS) Analogue Supply (VCC – VRFGND) Operating Temperature Local Oscillator Input Output Frequency Range DC Parameter - Supply Current Total Current Consumption: Powersave mode Bias only Operating Tx Operating Rx IF/RF Amplifier and Quadrature Demodulator Performance Figures: Gain Noise figure Third order intercept point (input) Comprehensive technical datasheet and support material is available from the CML website. Click here to link to the CML website or search for: CMX973 FirmASIC, FirmCODEC, RALCWI, Function Image and DuraTALK are trademarks of CML Microsystems Plc. Phone: +44 (0) 1621 875500 +1 336 744 5050 +65 62 888129 800 638 5577 Fax: +44 (0) 1621 875600 +1 336 638 5577 +65 62 888230 Email Sales: [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] Email Tech Support: www.cmlmicro.com © 2012 CML Microsystems Plc Search for: cmlmicro 4