Analog Devices Inc. ADL5331-EVALZ

Overview

ADL5331-EVALZ from Analog Devices is an evaluation board designed to characterize and prototype the ADL5331 voltage-controlled variable gain amplifier/attenuator (VGA) operating from 1 MHz to 1.2 GHz. It supports differential RF input/output, provides full access to all 24 pins of the ADL5331 LFCSP package, and enables rapid validation of gain control linearity (40 mV/dB), output IP3 (up to 47 dBm at 100 MHz), noise floor (−149 dBm/Hz), and power-down functionality (250 µA standby).

For engineers reviewing the ADL5331-EVALZ datasheet, ADL5331-EVALZ schematic, ADL5331-EVALZ layout, or ADL5331-EVALZ BOM, this board delivers production-relevant RF performance verification for transmit/receive power control in CATV distribution, CMTS systems, and IQ modulator interfaces - with on-board baluns, decoupling networks, and configurable biasing.

Technical Context

The ADL5331-EVALZ implements the full signal path of the ADL5331 IC: differential 50 Ω input stage, proprietary linear-in-dB voltage-controlled attenuator, and transimpedance output stage with 20 Ω differential impedance. It incorporates M/A-COM ETC1-1-13 1:1 baluns for single-ended 50 Ω interface and supports both differential and single-ended configurations per Figure 16 and Figure 17 of the ADL5331 datasheet.

Board-level design includes dedicated VPS1/VPS2 supply rails (4.75–5.25 V), ENBL logic control, GAIN pin test points, and RF chokes (0.68 µH) with 100 pF AC-coupling capacitors optimized for operation down to 1 MHz. The layout features grounded exposed pad connection, multi-layer decoupling (100 pF + 0.1 µF per supply pin), and test loops for INHI/INLO/OPHI/OPLO probing.

Key Specifications

Availability

ADL5331-EVALZ is available at Aetrix Electronics and suitable for RF prototyping, AGC loop development, CMTS transmit validation, and IQ modulator interface testing requiring stable component supply and traceable evaluation hardware.

Supply support for ADL5331-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 RF ICs, headquartered in Norwood, MA, with decades of expertise in precision signal processing and wireless infrastructure solutions.

The ADL5331-EVALZ belongs to Analog Devices' RF & Microwave Evaluation Platform family, engineered specifically to accelerate time-to-test for voltage-controlled gain devices used in broadband communications, cable infrastructure, and instrumentation applications.

FAQ

What is the primary purpose of the ADL5331-EVALZ?

The ADL5331-EVALZ is an evaluation board designed exclusively for the ADL5331 voltage-controlled amplifier/attenuator. It enables engineers to validate key performance metrics-including gain flatness (±0.09 dB), OIP3 (47 dBm at 100 MHz), noise floor (−149 dBm/Hz), and gain control linearity (40 mV/dB)-under real-world RF conditions using the exact 24-lead LFCSP package and pinout of the ADL5331.

Does the ADL5331-EVALZ support both differential and single-ended RF interfaces?

Yes, the ADL5331-EVALZ supports both configurations. It ships with M/A-COM ETC1-1-13 1:1 baluns for differential-to-single-ended conversion at input and output (per Figure 16), and also allows single-ended drive by terminating one input (e.g., INLO) to ground while driving INHI-exactly as documented in the ADL5331 datasheet Figure 17.

How is power-down functionality implemented on the ADL5331-EVALZ?

Power-down is controlled via the ENBL pin of the ADL5331, accessible through SW1A and test point ENB_A on the ADL5331-EVALZ. Applying logic low (≤0.8 V) reduces ADL5331 current consumption to 250 µA, and the board includes pull-up resistors and routing compliant with the ADL5331's absolute maximum ratings and enable threshold specifications.

What balun and RF choke values are used on the ADL5331-EVALZ?

The ADL5331-EVALZ uses M/A-COM ETC1-1-13 1:1 transmission-line baluns for broadband 50 Ω matching and 0.68 µH RF chokes (L1A/L2A) on the OPHI/OPLO outputs. These values match the reference design in the ADL5331 datasheet Figure 15 and are optimized for operation from 1 MHz to 1.2 GHz with minimal insertion loss and phase imbalance.

Can the ADL5331-EVALZ be used with the AD8319 log detector in an AGC loop?

Yes-the ADL5331-EVALZ is fully compatible with AGC implementations using the AD8319. Its GAIN pin test point (GNA), ENBL control, and output sampling paths align with the AD8319 interface shown in ADL5331 datasheet Figure 19, supporting closed-loop power control with ±0.5 dB conformance error across 25 dB of output power range.