Analog Devices Inc. HMC424G16

Overview

HMC424G16 from Analog Devices (formerly Hittite Microwave) is a GaAs MMIC 6-bit digital attenuator in a hermetic 16-lead SMT package, operating from DC to 3 GHz with 0.5 dB LSB steps up to 31.5 dB total attenuation, <3 dB typical insertion loss, ±0.5 dB typical step error, and +32 dBm IIP3 - deployed in telecom infrastructure RF front-ends.

For engineers reviewing the HMC424G16 datasheet, HMC424G16 pinout, HMC424G16 application, or HMC424G16 equivalent, key selection criteria include DC–3 GHz bandwidth, 0.5 dB LSB resolution, -5 V single-bias operation, 16-lead glass/metal hermetic package compatibility, and RF power handling up to +22 dBm P0.1dB.

Technical Context

The HMC424G16 implements a broadband GaAs-based switched-resistor attenuator architecture with six independent CMOS-compatible control inputs (V1–V6), each toggled between 0 V and -5 V to select bit states. It requires only a single -5 V bias (Vee) and draws ≤70 μA per control line.

Its RF path is DC-coupled with 50 Ω matched RF1/RF2 ports, enabling baseband-to-RF signal conditioning. Return loss exceeds 12 dB across DC–3 GHz in all attenuation states, supporting stable impedance matching in sensitive receiver and transmitter chains.

Key Specifications

Pinout & Package

Package: 16-lead hermetic glass/metal surface-mount package (alumina-loaded borosilicate glass body, Kovar base/cover, gold-plated leads and paddle). Requires soldering all ground leads and ground paddle to PCB RF ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with HMC424G16, HMC624LP4E extends usable bandwidth but sacrifices hermetic reliability, while ADL5240 adds SPI control and finer resolution at the cost of environmental robustness and analog control simplicity.

Availability

HMC424G16 is available at Aetrix Electronics and suitable for telecom infrastructure, military radios and radar, space applications, and test instrumentation requiring stable component supply, long-lifecycle availability, and hermetically sealed RF performance.

Supply support for HMC424G16 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 maintains its high-frequency RF product portfolio, specializing in GaAs and SiGe MMIC solutions for defense, aerospace, and communications.

The HMC424G16 belongs to Hittite's legacy digital attenuator family designed specifically for high-reliability, DC–3 GHz RF signal conditioning in mission-critical military, space, and instrumentation systems.

FAQ

What is the operating temperature range for the HMC424G16?

The HMC424G16 is specified for operation from -55°C to +85°C ambient temperature. Its hermetic glass/metal package and GaAs die construction enable stable RF performance across this full military-grade range, with measured bit error and insertion loss remaining within datasheet limits at both extremes.

Does the HMC424G16 require external blocking capacitors on RF1 and RF2?

Yes - the HMC424G16 features DC-coupled RF1 and RF2 ports, so external DC-blocking capacitors are required if the connected RF line carries a non-zero DC bias. The evaluation board uses 100 pF capacitors (C2, C3), and design guidelines recommend low-ESR, high-Q RF capacitors sized for the target frequency band.

What is the maximum RF input power the HMC424G16 can handle?

The HMC424G16 has an absolute maximum RF input power rating of +25 dBm (316 mW) across 0.5–13 GHz, but its linear operating limit is defined by P0.1dB at +22 dBm (1.6 W) from 1–3 GHz. Exceeding this causes measurable compression and degraded attenuation accuracy, especially in high-attenuation states.

Can the HMC424G16 be operated with control voltages other than 0 V and -5 V?

No - the HMC424G16 truth table and bias specifications define valid logic states only at 0 V (low) and -5 V ±0.5 V (high) for V1–V6. Intermediate voltages cause undefined attenuation states and increased bit error; the control interface is not compatible with positive logic or mixed-voltage signaling without level-shifting circuitry.

Is the HMC424G16 pin-compatible with other Hittite digital attenuators like the HMC624LP4E?

No - the HMC424G16 uses a 16-lead hermetic package with specific pin assignments (e.g., Vee on Pin 7, RF1/RF2 on Pins 3/10), whereas the HMC624LP4E uses a 24-lead QFN with different pinout, biasing, and thermal pad configuration. Direct replacement would require PCB redesign and layout changes.