Analog Devices Inc. AD8347-EVALZ

Overview

AD8347-EVALZ from Analog Devices is an evaluation board for the AD8347 direct-conversion quadrature demodulator IC, supporting RF input frequencies from 0.8 GHz to 2.7 GHz. It provides full access to all 28 pins of the AD8347 in a 28-lead TSSOP package, includes on-board baluns for single-ended LO/RF interface, and enables AGC loop validation, I/Q amplitude/phase error measurement, and baseband output characterization into ADCs such as AD9201 and AD9283.

For engineers reviewing the AD8347-EVALZ datasheet, AD8347-EVALZ pinout, AD8347-EVALZ application, or AD8347-EVALZ equivalent, this board supports rapid prototyping of cellular base station receivers, wireless local loop transceivers, satellite modem front-ends, and RF instrumentation requiring calibrated I/Q demodulation with <±1° quadrature phase accuracy and 0.3 dB I/Q amplitude balance.

Technical Context

The AD8347-EVALZ implements the complete signal chain of the AD8347 IC: RF input passes through dual-stage VGA → polyphase LO splitter → Gilbert-cell mixers → baseband VGAs → fixed-gain differential output amplifiers. All critical biasing (VREF = 1 V, VCMO programmable), AGC feedback (VAGC→VGIN), and offset nulling (IOFS/QOFS) paths are routed to test points or headers.

It integrates matched 50 Ω RF and LO input networks with selectable termination (with/without 200 Ω shunt), differential I/Q baseband outputs terminated to 10 kΩ loads, and decoupling for all three supply rails (VPS1/VPS2/VPS3). The board supports both AGC and manual gain control modes via jumper-selectable VGIN sourcing.

Key Specifications

Availability

AD8347-EVALZ is available at Aetrix Electronics and suitable for cellular base station development, satellite modem prototyping, and RF instrumentation design requiring stable component supply and traceable evaluation hardware.

Supply support for AD8347-EVALZ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The AD8347-EVALZ belongs to Analog Devices' RF & Microwave Evaluation Platform family, designed specifically to accelerate development of high-linearity, wideband direct-conversion receivers for wireless infrastructure and test equipment.

FAQ

What is the primary function of the AD8347-EVALZ?

The AD8347-EVALZ is an evaluation board for the AD8347 quadrature demodulator IC. It enables engineers to characterize RF-to-baseband conversion performance-including I/Q phase accuracy, amplitude balance, AGC response, and mixer linearity-across the 0.8–2.7 GHz band. It is not a standalone IC but a fully populated, tested PCB with test points, jumpers, and connectors for lab validation of the AD8347's demodulation behavior in real systems.

Does the AD8347-EVALZ support both manual gain control and automatic gain control modes?

Yes, the AD8347-EVALZ supports both modes. For manual control, VGIN is driven externally via a header; for AGC mode, the on-board detector (VDT1/VDT2 inputs tied to IMXO/QMXO) feeds VAGC back to VGIN through a jumper. This allows immediate validation of closed-loop gain stability, setpoint adjustment, and dynamic range compression per the AD8347's 69.5 dB AGC range.

Can the AD8347-EVALZ be used with single-ended RF and LO sources?

Yes. The AD8347-EVALZ includes Mini-Circuits TC3-1T baluns for both RF and LO paths, enabling clean single-ended-to-differential conversion. The RF input network supports optional 200 Ω shunt termination for improved 50 Ω match, and LO drive level is verified at −8 dBm typical-matching the AD8347's specified low-LO-drive requirement without external amplification.

What ADCs are compatible with the baseband outputs of the AD8347-EVALZ?

The AD8347-EVALZ baseband outputs (IOPP/IOPN and QOPP/QOPN) are optimized for direct connection to ADCs requiring differential 760 mV p-p input swing and 1 V common-mode level, including the AD9201 and AD9283 as explicitly cited in the AD8347 datasheet. Output swing, DC offset (<±50 mV differential), and bandwidth (65 MHz) meet timing and SNR requirements of these 10-bit/12-bit converters.

How is dc offset compensation implemented on the AD8347-EVALZ?

The AD8347-EVALZ routes IOFS and QOFS pins to test points and 0.1 μF capacitor footprints, enabling either passive offset nulling (capacitor to ground) or active override (external 1 V bias). This matches the AD8347's internal offset correction loop, allowing users to measure residual baseband dc offset (<2 mV at IMXO/QMXO under max gain) and validate correction efficacy across temperature and gain settings.