DC to 50 MHz, Dual I/Q Demodulator and Phase Shifter Data Sheet AD8333 FEATURES FUNCTIONAL BLOCK DIAGRAM Dual integrated I/Q demodulator 16 phase select options on each output (22.5 per step) Quadrature demodulation accuracy BIAS PH12 Phase accuracy: 0.1 CH 1 SEL LOGIC 0 Amplitude balance: 0.05 dB PH13 I1NO I1PO Bandwidth COMM 4 LO: 10 kHz to 200 MHz 90 Q1PO RF: dc to 50 MHz 4LOP Q1NO BUF 4 Baseband: determined by external filtering 90 4LON Q2NO Output dynamic range: 159 dB/Hz Q2PO LO drive > 0 dBm (50 ) 4 LO > 1 MHz 0 I2PO Supply: 5 V PH23 I2NO Power consumption: 190 mW/channel (380 mW total) CH 2 SEL LOGIC Power-down PH22 APPLICATIONS Medical imaging (CW ultrasound beamforming) Figure 1. Phased array systems (radar and adaptive antennas) Communication receivers GENERAL DESCRIPTION 1 The AD8333 is a dual phase-shifter and I/Q demodulator that Phase shift is defined by the output of one channel relative to enables coherent summing and phase alignment of multiple another. For example, if the code of Channel 1 is adjusted to analog data channels. It is the first solid-state device suitable for 0000 and that of Channel 2 is adjusted to 0001 and the same beamformer circuits, such as those used in high performance signal is applied to both RF inputs, the output of Channel 2 medical ultrasound equipment featuring CW Doppler. The RF leads that of Channel 1 by 22.5. inputs interface directly with the outputs of the dual-channel, The I and Q outputs are provided as currents to facilitate sum- low noise preamplifiers included in the AD8332. mation. The summed current outputs are converted to voltages A divide-by-4 circuit generates the internal 0 and 90 phases by a high dynamic range, current-to-voltage (I-V) converter, such of the local oscillator (LO) that drive the mixers of a pair of as the AD8021, configured as a transimpedance amplifier. The matched I/Q demodulators. resultant signal is then applied to a high resolution ADC, such as the AD7665 (16 bit/570 kSPS). The AD8333 can be applied as a major element in analog beamformer circuits in medical ultrasound equipment. The two I/Q demodulators can be used independently in other nonbeamforming applications. In that case, a transimpedance The AD8333 features an asynchronous reset pin. When used amplifier is needed for each of the I and Q outputs, four in total in arrays, the reset pin sets all the LO dividers in the same state. for the dual I/Q demodulator. Sixteen discrete phase rotations in 22.5 increments can be selected independently for each channel. For example, if Channel 1 is used The dynamic range is 159 dB/Hz at the I and Q outputs, but the as a reference and the RF signal applied to Channel 2 has an I/Q following transimpedance amplifier is an important element in phase lead of 45, Channel 2 can be phase aligned with Channel 1 maintaining the overall dynamic range, and attention needs to by choosing the correct code. be paid to optimal component selection and design. The AD8333 is available in a 32-lead LFCSP (5 mm 5 mm) package for the industrial temperature range of 40C to +85C. 1 Protected by US Patent 7,760,833. Rev. F Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 20052016 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com PH11 PH10 RF2P RFIP RF2N RFIN ENBL 05543-001AD8333 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Channel Summing ..................................................................... 21 Applications ....................................................................................... 1 Dynamic Range Inflation .......................................................... 23 Functional Block Diagram .............................................................. 1 Disabling the Current Mirror and Decreasing Noise ............ 23 General Description ......................................................................... 1 Applications Information .............................................................. 25 Revision History ............................................................................... 3 Logic Inputs and Interfaces ....................................................... 25 Specifications ..................................................................................... 4 Reset Input .................................................................................. 25 Absolute Maximum Ratings ............................................................ 6 Connecting to the LNA of the AD8331/AD8332/AD8334/AD8335 VGAs ............................ 25 ESD Caution .................................................................................. 6 Interfacing to Other Amplifiers ............................................... 26 Pin Configuration and Function Descriptions ............................. 7 LO Input ...................................................................................... 26 Equivalent Input Circuits ................................................................ 8 Evaluation Board ............................................................................ 27 Typical Performance Characteristics ............................................. 9 Features and Options ................................................................. 27 Test Circuits ..................................................................................... 15 Measurement Setup.................................................................... 28 Theory of Operation ...................................................................... 18 Evaluation Board Schematic and Artwork .................................. 29 Quadrature Generation ............................................................. 18 Board Layout ............................................................................... 31 I/Q Demodulator and Phase Shifter ........................................ 18 Outline Dimensions ....................................................................... 32 Dynamic Range and Noise ........................................................ 19 Ordering Guide .......................................................................... 32 Summation of Multiple Channels (Analog Beamforming) .. 20 Phase Compensation and Analog Beamforming ................... 20 Rev. F Page 2 of 32