Low Distortion Mixer AD831 FEATURES FUNCTIONAL BLOCK DIAGRAM Doubly Balanced Mixer Low Distortion +24 dBm Third Order Intercept (IP3) +10 dBm 1 dB Compression Point Low LO Drive Required: 10 dBm Bandwidth 500 MHz RF and LO Input Bandwidths 250 MHz Differential Current IF Output DC to >200 MHz Single-Ended Voltage IF Output Single- or Dual-Supply Operation DC Coupled Using Dual Supplies All Ports May Be DC Coupled No Lower Frequency LimitOperation to DC User-Programmable Power Consumption APPLICATIONS building a quadrature-amplitude modulator or image reject mixer, High Performance RF/IF Mixer the differential current outputs of two AD831s may be summed Direct to Baseband Conversion by connecting them together. Image-Reject Mixers An integral low noise amplifier provides a single-ended voltage I/Q Modulators and Demodulators output and can drive such low impedance loads as filters, 50 amplifier inputs, and A/D converters. Its small signal bandwidth exceeds 200 MHz. A single resistor connected between pins PRODUCT DESCRIPTION OUT and FB sets its gain. The amplifiers low dc offset allows The AD831 is a low distortion, wide dynamic range, monolithic its use in such direct-coupled applications as direct-to-baseband mixer for use in such applications as RF to IF downconversion conversion and quadrature-amplitude demodulation. in HF and VHF receivers, the second mixer in DMR base sta- The mixers SSB noise figure is 10.3 dB at 70 MHz using its tions, direct-to-baseband conversion, quadrature modulation and output amplifier and optimum source impedance. Unlike passive demodulation, and doppler shift detection in ultrasound imaging mixers, the AD831 has no insertion loss and does not require an applications. The mixer includes an LO driver and a low noise external diplexer or passive termination. output amplifier and provides both user-programmable power consumption and third order intercept point. A programmable-bias feature allows the user to reduce power consumption, with a reduction in the 1 dB compression point and The AD831 provides a +24 dBm third order intercept point for third-order intercept. This permits a tradeoff between dynamic 10 dBm LO power, thus improving system performance and range and power consumption. For example, the AD831 may be reducing system cost compared to passive mixers, by eliminating used as a second mixer in cellular and two-way radio base stations the need for a high power LO driver and its attendant shielding at reduced power while still providing a substantial performance and isolation problems. improvement over passive solutions. The RF, IF, and LO ports may be dc or ac coupled when the mixer is operating from 5 V supplies or ac coupled when oper- PRODUCT HIGHLIGHTS ating from a single-supply of 9 V minimum. The mixer operates 1. 10 dBm LO Drive for a +24 dBm Output Referred Third with RF and LO inputs as high as 500 MHz. Order Intercept Point The mixers IF output is available as either a differential current 2. Single-Ended Voltage Output output or a single-ended voltage output. The differential output is 3. High Port-to-Port Isolation from a pair of open collectors and may be ac coupled via a trans- former or capacitor to provide a 250 MHz output bandwidth. In 4. No Insertion Loss downconversion applications, a single capacitor connected across 5. Single- or Dual-Supply Operation these outputs implements a low-pass filter to reduce harmonics directly at the mixer core, simplifying output filtering. When 6. 10.3 dB Noise Figure Rev. D 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 license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Tel: 781.329.4700 2018 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com (T = +25C and V = 5 V unless otherwise noted A S AD831 AD831SPECIFICATIONS all values in dBm assume 50 load.) Parameter Conditions Min Typ Max Unit RF INPUT Bandwidth 10 dBm Signal Level, IP3 +20 dBm 400 MHz 10.7 MHz IF and High Side Injection See Figure 1 1 dB Compression Point 10 dBm Common-Mode Range 1 V Bias Current DC Coupled 160 500 A DC Input Resistance Differential or Common Mode 1.3 k Capacitance 2 pF IF OUTPUT Bandwidth Single-Ended Voltage Output, 3 dB Level = 0 dBm, R = 100 200 MHz L Conversion Gain Terminals OUT and VFB Connected 0 dB Output Offset Voltage DC Measurement LO Input Switched 1 40 +15 +40 mV Slew Rate 300 V/s Output Voltage Swing R = 100 , Unity Gain 1.4 V L Short Circuit Current 75 mA LO INPUT Bandwidth 10 dBm Input Signal Level 400 MHz 10.7 MHz IF and High Side Injection Maximum Input Level 1 +1 V Common-Mode Range 1 +1 V Minimum Switching Level Differential Input Signal 200 mV p-p Bias Current DC Coupled 17 50 A Resistance Differential or Common Mode 500 Capacitance 2 pF ISOLATION BETWEEN PORTS LO-to-RF LO = 100 MHz, R = 50 , 10.7 MHz IF 70 dB S LO-to-IF LO = 100 MHz, R = 50 , 10.7 MHz IF 30 dB S RF-to-IF RF = 100 MHz, R = 50 , 10.7 MHz IF 45 dB S DISTORTION AND NOISE LO = 10 dBm, f = 100 MHz, IF = 10.7 MHz Third Order Intercept Output Referred, 100 mV LO Input 24 dBm Second Order Intercept Output Referred, 100 mV LO Input 62 dBm 1 dB Compression Point R = 100 , R = 10 dBm L BIAS Noise Figure, SSB Matched Input, RF = 70 MHz, IF = 10.7 MHz 10.3 dB Matched Input, RF = 150 MHz, IF = 10.7 MHz 14 dB POWER SUPPLIES Recommended Supply Range Dual Supply 4.5 5.5 V Single Supply 9 11 V Quiescent Current* For Best Third Order Intercept Point Performance 100 125 mA BIAS Pin Open Circuited *Quiescent current is programmable. Specifications subject to change without notice. REV. D 2 REV. C 3