Features and Benefits
- Doubly Balanced Mixer
- Low Distortion
+24 dBm Third Order Intercept (IP3)
+10 dBm 1 dB Compression Point
500 MHz RF and LO Input Bandwidths
250 MHz Differential Current IF Output
DC to >200 MHz Single-Ended Voltage IF Output
- Low LO Drive Required: –10 dBm
- Single- or Dual-Supply Operation
- DC Coupled Using Dual Supplies
All Ports May Be DC Coupled
No Lower Frequency Limit—Operation to DC
- User-Programmable Power Consumption
The AD831 is a low distortion, wide dynamic range, monolithic mixer for use in such applications as RF to IF down conversion in HF and VHF receivers, the second mixer in DMR base stations, direct-to-baseband conversion, quadrature modulation and demodulation, and doppler-shift detection in ultrasound imaging applications. The mixer includes an LO driver and a low-noise output amplifier and provides both user-programmable power consumption and 3rd-order intercept point.
The AD831 provides a +24 dBm third-order intercept point for -10 dBm LO power, thus improving system performance and reducing system cost compared to passive mixers, by eliminating the need for a high power LO driver and its attendant shielding and isolation problems.
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 operating from a single supply of 9 V minimum. The mixer operates with RF and LO inputs as high as 500 MHz.
The mixer's IF output is available as either a differential current output or a single-ended voltage output. The differential output is from a pair of open collectors and may be ac coupled via a transformer or capacitor to provide a 250 MHz output bandwidth. In down-conversion applications, a single capacitor connected across these outputs implements a low-pass filter to reduce harmonics directly at the mixer core, simplifying output filtering. When building a quadrature-amplitude modulator or image reject mixer, the differential current outputs of two AD831s may be summed by connecting them together.
An integral low noise amplifier provides a single-ended voltage output and can drive such low impedance loads as filters, 50 W amplifier inputs, and A/D converters. Its small signal bandwidth exceeds 200 MHz. A single resistor connected between pins OUT and FB sets its gain. The amplifier's low dc offset allows its use in such direct-coupled applications as direct-to-baseband conversion and quadrature-amplitude demodulation.
The mixer's SSB noise figure is 10.3 dB at 70 MHz using its output amplifier and optimum source impedance. Unlike passive mixers, the AD831 has no insertion loss and does not require an external diplexer or passive termination.
A programmable-bias feature allows the user to reduce power consumption, with a reduction in the 1 dB compression point and third-order intercept. This permits a tradeoff between dynamic range and power consumption. For example, the AD831 may be used as a second mixer in cellular and two-way radio base stations at reduced power while still providing a substantial performance improvement over passive solutions.
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (1)
EVAL-AD831EBZ is a fully populated, 4-layer, FR4-based evaluation board. RF input, LO input, and IF output connections with single ended setups are featured. Access to the ±5V/100 mA supply is achieved with a 2 pin header connector to the +5V and -5V jumpers; it has a range from ± 4.5 to ± 5.5V.
Tools & Simulations
ADIsimPLL enables the rapid and reliable evaluation of new high performance PLL products from ADI. It is the most comprehensive PLL Synthesizer design and simulation tool available today. Simulations performed include all key non-linear effects that are significant in affecting PLL performance. ADIsimPLL removes at least one iteration from the design process, thereby speeding the design- to-market.
ADIsimRF is an easy-to-use RF signal chain calculator. Cascaded gain, noise, distortion and power consumption can be calculated, plotted and exported for signal chains with up to 50 stages. ADIsimRF also includes an extensive data base of device models for ADI’s RF and mixed signal components.
Product Selection Guide (1)
Technical Articles (2)
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
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The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.