Analog Devices Inc. HMC424LH5TR

Overview

HMC424LH5TR from Analog Devices (formerly Hittite Microwave) is a GaAs MMIC 6-bit digital attenuator in a hermetic leadless SMT package, delivering 0.5 dB LSB steps across DC–13 GHz with ≤3.2 dB typical insertion loss (DC–4 GHz), ±0.4 dB typical attenuation accuracy, and +32 dBm IIP3 - deployed in military radar front-ends and space-grade RF signal conditioning paths.

For engineers reviewing the HMC424LH5TR datasheet, HMC424LH5TR pinout, HMC424LH5TR application, or HMC424LH5TR equivalent, key selection criteria include DC-coupled 50 Ω RF ports, -5 V single-supply biasing, six 0/–5 V control lines for bit-selectable attenuation states, and MIL-PRF-38535 Class B/S screening suitability for high-reliability RF subsystems.

Technical Context

The HMC424LH5TR implements a broadband GaAs MMIC architecture with fully DC-coupled RF1/RF2 ports and six independent TTL-compatible control inputs (V6–V1), each toggling between 0 V and –5 V to activate 0.5, 1, 2, 4, 8, and 16 dB attenuation bits. Bias is supplied via a single –5 V (±10%) Vee rail drawing 3 mA typical.

It achieves <3.8 dB insertion loss up to 8 GHz, maintains ≥12 dB return loss across DC–13 GHz at all attenuation states, and delivers 30 ns typical RF rise/fall time with 50 ns switching delay - enabling precise amplitude control in wideband test instrumentation and ECM signal chains without external DC blocking.

Key Specifications

Pinout & Package

Hermetic 12-pad leadless ceramic package (5 mm × 5 mm), with exposed ground paddle requiring solder connection to PCB RF ground plane. Ground pads (Pins 8, 10, 12) and package base must be soldered for optimal RF performance and thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with HMC624LP4E and QM11036, the HMC424LH5TR uniquely combines DC–13 GHz coverage, true DC-coupled ports, hermetic reliability, and MIL screening - making it irreplaceable in space-qualified and military radar signal chains demanding zero-frequency gap and long-term parametric stability.

Availability

HMC424LH5TR is available at Aetrix Electronics and suitable for telecom infrastructure, military radar, and space systems requiring stable component supply, extended temperature operation, and certified screening compliance.

Supply support for HMC424LH5TR 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 acquired Hittite Microwave in 2014 and integrates its high-frequency RF portfolio into precision signal processing solutions for defense, aerospace, and communications markets.

The HMC424LH5TR belongs to the Hittite digital attenuator product line, engineered specifically for broadband, high-linearity, and high-reliability RF amplitude control in mission-critical electronic warfare and satellite systems.

FAQ

What is the operating voltage requirement for HMC424LH5TR?

The HMC424LH5TR requires a single –5 V DC bias supply (Vee) with ±10% tolerance and draws 3 mA typical current. Control inputs (V6–V1) operate between 0 V (logic low) and –5 V (logic high). No positive supply is needed - this negative-only rail simplifies integration into legacy RF subsystems using standard negative voltage regulators.

Does HMC424LH5TR support DC-coupled RF operation?

Yes, HMC424LH5TR features fully DC-coupled RF1 and RF2 ports matched to 50 Ω, enabling baseband and low-frequency signal attenuation down to 0 Hz. External DC blocking capacitors are required only if the connected RF stage operates at non-zero DC potential - otherwise, direct coupling preserves phase integrity and eliminates capacitor-induced roll-off.

What is the maximum RF input power rating for HMC424LH5TR?

HMC424LH5TR has an absolute maximum RF input power rating of +25 dBm across 0.5–13 GHz. Under continuous operation, its 0.1 dB compression point is +22 dBm (1–13 GHz), and its IIP3 remains +32 dBm in all attenuated states - confirming robust linearity for multi-carrier and pulsed RF environments.

Is HMC424LH5TR suitable for space applications?

Yes, HMC424LH5TR is offered with MIL-PRF-38535 Class B or Class S screening, including hermeticity testing, thermal cycling, and radiation hardness assurance. Its ceramic package, gold-plated leads, and proven performance from –40 °C to +85 °C make it qualified for LEO and GEO satellite payloads where long-term reliability under vacuum and radiation is mandatory.

How does the bit control logic work on HMC424LH5TR?

HMC424LH5TR uses six dedicated control inputs (V6–V1) corresponding to 16, 8, 4, 2, 1, and 0.5 dB bits. A logic high (–5 V) activates the bit; logic low (0 V) disables it. The truth table confirms any combination yields summed attenuation - e.g., V6=high + V3=high + V1=high = 16 + 4 + 0.5 = 20.5 dB - with ±0.4 dB typical step error referenced to insertion loss.