Analog Devices Inc. 105408-HMC425LP3

Overview

105408-HMC425LP3 from Analog Devices (formerly Hittite Microwave) is a GaAs MMIC 6-bit digital attenuator with 0.5 dB LSB steps, operating from 2.2 to 8.0 GHz, delivering 31.5 dB max attenuation, ±0.5 dB typical bit error, and 3.8 dB typical insertion loss at 6.0–8.0 GHz - deployed in microwave radio, VSAT, and broadband telecom RF front-ends.

For engineers reviewing the 105408-HMC425LP3 datasheet, 105408-HMC425LP3 pinout, 105408-HMC425LP3 application, or 105408-HMC425LP3 equivalent, key selection criteria include frequency coverage (2.2–8.0 GHz), control voltage compatibility (0/+5 V per bit), IIP3 (+40 dBm min), +3 to +5 V single-supply operation, and 3×3 mm QFN package integration into compact SMT RF designs.

Technical Context

This device implements a positive-control, parallel 6-bit GaAs MMIC architecture with discrete attenuation bits (0.5/1/2/4/8/16 dB), enabling precise RF signal level management across microwave bands without analog tuning. Each bit is driven by an independent TTL/CMOS-compatible control line toggled between 0 and +5 V.

It operates with a single +3 to +5 V bias supply, draws only 30 µA typical current at Vdd = +5 V, and maintains RF port match (≥15 dB return loss) and phase stability across all 64 attenuation states - critical for amplitude-modulated transceivers and adaptive gain control loops.

Key Specifications

Pinout & Package

105408-HMC425LP3 is housed in a 3×3 mm, 16-lead leadless plastic QFN package (MSL1, Sn/Pb finish) with exposed ground paddle requiring solder connection to PCB RF ground plane for thermal and RF performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digital RF attenuator applications.

Compared with HMC425LP3E and QM11036, the 105408-HMC425LP3 offers broader frequency support (up to 8.0 GHz), lower insertion loss in the upper band, and superior linearity - making it the preferred choice for wideband military and satellite communication systems demanding full-band fidelity.

Availability

105408-HMC425LP3 is available at Aetrix Electronics and suitable for microwave radio, VSAT terminal, and broadband telecom infrastructure requiring stable component supply, long-term lifecycle assurance, and traceable sourcing from authorized channels.

Supply support for 105408-HMC425LP3 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, serving communications, industrial, automotive, and aerospace markets with precision signal processing solutions.

The HMC425 product line delivers GaAs MMIC digital attenuators optimized for broadband microwave systems requiring high accuracy, low distortion, and compact SMT integration - targeting defense, satellite, and 5G infrastructure applications.

FAQ

What is the operating temperature range for the 105408-HMC425LP3?

The 105408-HMC425LP3 is rated for operation from −40°C to +85°C ambient temperature. Its GaAs MMIC process and QFN package ensure stable attenuation accuracy and return loss across this full industrial/military range, with bit error remaining within ±0.5 dB typical across temperature extremes.

Does the 105408-HMC425LP3 require external DC blocking capacitors?

Yes, the 105408-HMC425LP3 has DC-coupled RFIN and RFOUT pins matched to 50 Ω, so external DC blocking capacitors are mandatory on both RF ports to prevent bias disruption and ensure proper impedance matching in AC-coupled systems.

What is the maximum RF input power the 105408-HMC425LP3 can handle?

The 105408-HMC425LP3 supports +30 dBm absolute maximum RF input power across 2.4–8.0 GHz. At typical operating conditions (Vdd = +5 V), its P1dB is +22 dBm, ensuring reliable linear operation below compression in high-power transmitter stages.

Can the 105408-HMC425LP3 be used with a 3.3 V control logic interface?

Yes - the 105408-HMC425LP3 control inputs (V1–V6) accept logic-high voltages from +3 to +5 V, making them compatible with standard 3.3 V CMOS/TTL outputs without level shifters; logic-low threshold remains ≤0.2 V at 10 µA sink current.

Is the exposed paddle on the 105408-HMC425LP3 package required to be grounded?

Yes, the exposed metal paddle on the 105408-HMC425LP3 must be soldered to the PCB's RF ground plane. This connection provides critical thermal dissipation, RF shielding, and return path integrity - omission degrades insertion loss, return loss, and power handling capability.