0.8 GHz to 2.5 GHz Quadrature Modulator AD8346 FEATURES FUNCTIONAL BLOCK DIAGRAM High accuracy IBBP 1 16 QBBP 1 degree rms quadrature error 1.9 GHz 0.2 dB I/Q amplitude balance 1.9 GHz IBBN 2 15 QBBN Broad frequency range: 0.8 GHz to 2.5 GHz COM1 3 14 COM4 Sideband suppression: 46 dBc 0.8 GHz Sideband suppression: 36 dBc 1.9 GHz COM1 COM4 4 13 Modulation bandwidth: dc to 70 MHz LOIN VPS2 5 12 0 dBm output compression level 0.8 GHz PHASE LOIP SPLITTER VOUT 6 11 Noise floor: 147 dBm/Hz Single 2.7 V to 5.5 V supply VPS1 COM3 7 10 Quiescent operating current: 45 mA AD8346 ENBL BIAS COM2 8 9 Standby current: 1 A 16-lead TSSOP Figure 1. APPLICATIONS Digital and spread spectrum communication systems Cellular/PCS/ISM transceivers Wireless LAN/wireless local loop QPSK/GMSK/QAM modulators Single-sideband (SSB) modulators Frequency synthesizers Image reject mixer GENERAL DESCRIPTION The AD8346 is a silicon RFIC I/Q modulator for use from This quadrature modulator can be used as the transmit mod- 0.8 GHz to 2.5 GHz. Its excellent phase accuracy and amplitude ulator in digital systems such as PCS, DCS, GSM, CDMA, and balance allow high performance direct modulation to RF. ISM transceivers. The baseband quadrature inputs are directly modulated by the LO signal to produce various QPSK and The differential LO input is applied to a polyphase network QAM formats at the RF output. phase splitter that provides accurate phase quadrature from 0.8 GHz to 2.5 GHz. Buffer amplifiers are inserted between Additionally, this quadrature modulator can be used with direct two sections of the phase splitter to improve the signal-to- digital synthesizers in hybrid phase-locked loops to generate noise ratio. The I and Q outputs of the phase splitter drive the signals over a wide frequency range with millihertz resolution. LO inputs of two Gilbert-cell mixers. Two differential V-to-I The AD8346 comes in a 16-lead TSSOP package, measuring converters connected to the baseband inputs provide the 6.5 mm 5.1 mm 1.1 mm. It is specified to operate over a baseband modulation signals for the mixers. The outputs of 40C to +85C temperature range and a 2.7 V to 5.5 V supply the two mixers are summed together at an amplifier which is voltage range. The device is fabricated on Analog Devices high designed to drive a 50 load. performance 25 GHz bipolar silicon process. Rev. A 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 rights of third parties that may result from its use. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Specifications subject to change without notice. No license is granted by implication Tel: 781.329.4700 www.analog.com or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective companies. Fax: 781.461.3113 2005 Analog Devices, Inc. All rights reserved. 05335-001AD8346 TABLE OF CONTENTS Specifications..................................................................................... 3 Bias ............................................................................................... 10 Absolute Maximum Ratings............................................................ 4 Basic Connections...................................................................... 11 ESD Caution.................................................................................. 4 LO Drive...................................................................................... 11 Pin Configuration and Function Descriptions............................. 5 RF Output.................................................................................... 11 Equivalent Circuits ........................................................................... 6 Interface to AD9761 TXDAC .................................................. 12 Typical Performance Characteristics ............................................. 7 AC-Coupled Interface ............................................................... 13 Circuit Description......................................................................... 10 Evaluation Board ............................................................................ 14 Overview...................................................................................... 10 Characterization Setups................................................................. 16 LO Interface................................................................................. 10 SSB Setup..................................................................................... 16 V-to-I Converter......................................................................... 10 CDMA Setup............................................................................... 17 Mixers .......................................................................................... 10 Outline Dimensions ....................................................................... 18 Differential-to-Single-Ended Converter ................................. 10 Ordering Guide .......................................................................... 18 REVISION HISTORY 6/05Rev. 0 to Rev. A Updated Format..................................................................Universal Changes to Figures 30, 31, 32........................................................ 14 Update Outline Dimensions ......................................................... 18 Changes to Ordering Guide .......................................................... 18 3/99Revision 0: Initial Version Rev. A Page 2 of 20