Analog Devices Inc. AD8309-EVALZ

Overview

AD8309-EVALZ from Analog Devices is an evaluation board designed to characterize the AD8309 5 MHz–500 MHz 100 dB demodulating logarithmic amplifier with limiter output. It provides full access to differential RF inputs (INHI/INLO), limiter outputs (LMHI/LMLO), RSSI output (VLOG), and programmable control pins (ENBL, LMDR, FLTR) on a pre-layout PCB with 50 Ω matched traces, SMA connectors, and decoupling networks. It supports rapid validation of RSSI linearity, limiter phase stability, and power-up timing in IF receiver signal chains.

For engineers reviewing the AD8309-EVALZ datasheet, AD8309-EVALZ pinout, AD8309-EVALZ application, or AD8309-EVALZ equivalent, this board enables hands-on verification of log-amp slope (20 mV/dB), intercept (–95 dBm), dynamic range (100 dB), limiter gain control, and temperature-stable RSSI scaling across –40°C to +85°C - critical for radar front-ends, spectrum analyzers, and wide-dynamic-range RF receivers.

Technical Context

The AD8309-EVALZ implements a complete test platform for the AD8309 IC, featuring edge-mounted SMA connectors for INHI/INLO and LMHI/LMLO, calibrated 50 Ω microstrip routing, on-board voltage regulation (3.3 V and 5 V options), and configurable biasing for LMDR and FLTR. It includes jumpers for ENBL logic control, selectable load termination (50 Ω/75 Ω/100 Ω), and test points for all critical nodes including VLOG, COM1, COM2, and VPS1/VPS2 supplies.

Designed per Analog Devices' reference layout guidelines, the board uses controlled-impedance routing, ground-plane isolation between analog and digital sections, and thermal vias under the AD8309ARU TSSOP-16 footprint. It supports both single-supply operation (2.7 V to 6.5 V) and dual-rail configurations, with provisions for external filter capacitors on FLTR and current-sense resistors on LMDR to validate limiter output current (0–10 mA) and RSSI bandwidth tuning.

Key Specifications

Availability

AD8309-EVALZ is available at Aetrix Electronics and suitable for RF receiver development, spectrum analyzer calibration, radar signal processing prototyping, and wide-dynamic-range IF measurement systems requiring stable component supply and traceable evaluation hardware.

Supply support for AD8309-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, with design centers worldwide and ISO 9001-certified manufacturing.

The AD8309-EVALZ belongs to Analog Devices' RF and microwave evaluation platform family, engineered specifically to accelerate characterization and integration of logarithmic amplifiers and IF limiting receivers into demanding communications, defense, and instrumentation applications.

FAQ

What is the primary purpose of the AD8309-EVALZ?

The AD8309-EVALZ is an official Analog Devices evaluation board intended exclusively for bench-level characterization and functional validation of the AD8309 demodulating logarithmic amplifier. It provides calibrated RF paths, accessible test points for all key signals (VLOG, LMHI, LMLO, ENBL, FLTR), and configurable biasing to verify RSSI slope (20 mV/dB), intercept (–95 dBm), limiter phase stability (±3°), and dynamic range (100 dB) per the AD8309 datasheet specifications.

Does the AD8309-EVALZ support both single-ended and differential RF input configurations?

No - the AD8309-EVALZ is optimized for differential operation only, matching the AD8309's native fully differential input architecture (INHI/INLO). It features two edge-mount SMA connectors routed as balanced 50 Ω microstrip pairs directly to the AD8309ARU TSSOP-16 footprint. Single-ended drive requires external balun circuitry not included on the board and is not validated by Analog Devices for AD8309-EVALZ use.

Can the AD8309-EVALZ be used to measure limiter output current and adjust gain via LMDR?

Yes - the AD8309-EVALZ includes a dedicated LMDR bias network with jumper-selectable resistor values (100 Ω to 400 Ω) and test points to monitor limiter output current (0–10 mA) and verify gain control per Figure 17 of the AD8309 datasheet. The board allows direct measurement of limiter current versus RLIM and correlation with additional supply current draw, enabling precise limiter stage optimization.

How does the AD8309-EVALZ handle RSSI bandwidth adjustment using the FLTR pin?

The AD8309-EVALZ provides solder pads and a test point for the FLTR pin, supporting external capacitor values from 0 pF up to 3300 pF as shown in Figure 6 of the AD8309 datasheet. This enables empirical tuning of RSSI output settling time (120–220 ns) and small-signal AC response, allowing users to trade off bandwidth for noise rejection in real-world IF detection scenarios without modifying the core AD8309-EVALZ layout.

Is the AD8309-EVALZ compatible with standard lab equipment such as spectrum analyzers and signal generators?

Yes - the AD8309-EVALZ uses industry-standard 50 Ω SMA connectors for RF input (INHI/INLO) and limiter output (LMHI/LMLO), and provides buffered, low-impedance access to VLOG (0.34–2.75 V) via test points and headers. It is fully compatible with benchtop signal generators (–78 dBm to +22 dBm range), spectrum analyzers, oscilloscopes, and DC power supplies, meeting all interface requirements specified in the AD8309-EVALZ user guide (UG-105).