Analog Devices Inc. HMC240A-SX

Overview

HMC240A-SX from Analog Devices (formerly Hittite Microwave) is a GaAs MMIC SPDT switch chip operating from DC to 4 GHz, delivering 0.5 dB typical insertion loss at 2 GHz, 28 dB typical isolation across the band, and +48 dBm IIP3 at 0.5–1.0 GHz. It supports dual-mode control (0/+5 V or –5/0 V), features reflective "off" states at RF1/RF2, and is used in microwave radio front-ends requiring broadband signal routing.

For engineers reviewing the HMC240A-SX datasheet, HMC240A-SX pinout, HMC240A-SX application, or HMC240A-SX equivalent, key selection criteria include its DC–4 GHz bandwidth, low 3 ns t_RISE/t_FALL, ±0.2 V control voltage tolerance, and requirement for DC blocking capacitors on all RF ports.

Technical Context

The HMC240A-SX implements a monolithic GaAs MESFET architecture with two independent negative/positive logic-compatible control inputs (A/B), enabling RFC-to-RF1 or RFC-to-RF2 path selection. Its reflective "off" state eliminates need for external termination at RF1/RF2, simplifying layout in compact RF modules.

It operates over –55°C to +85°C with Class 1A ESD sensitivity and requires wire bonding using 0.025 mm gold wire. All RF pads (1, 2, 3, 5, 7, 9) are DC-coupled and 50 Ω matched; pads 4 and 6 must be tied to RF/DC ground.

Key Specifications

Pinout & Package

Package: Bare die, 0.66 × 0.60 × 0.18 mm, gold bond pads, back-metallized for conductive epoxy mounting. Requires Gel-Pak® (GP-5) or waffle-pack shipping per ESD-sensitive handling protocol.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SPDT switch applications.

Compared with HMC545A-SX and QM11036, the HMC240A-SX delivers optimal balance of broadband performance, small die size (0.66 × 0.60 mm), and proven reliability in military-grade thermal cycling - making it preferred for space-constrained, high-isolation microwave radio designs where 4 GHz upper limit is sufficient.

Availability

HMC240A-SX is available at Aetrix Electronics and suitable for telecom infrastructure, microwave radio & VSAT, military & space, and test instrumentation applications requiring stable component supply, long-lifecycle support, and traceable GaAs MMIC sourcing.

Supply support for HMC240A-SX 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 portfolio, including GaAs MMIC switches, amplifiers, and mixers for defense, aerospace, and communications markets.

The HMC240A-SX belongs to Hittite's legacy SPDT GaAs switch family, engineered for broadband, high-isolation RF signal routing in microwave transceivers and EW systems where minimal insertion loss and fast switching are critical.

FAQ

What control voltage configurations does the HMC240A-SX support?

The HMC240A-SX supports two fully independent control modes: positive logic (0 V / +5 V) and negative logic (–5 V / 0 V), with ±0.2 V tolerance on each input. Either Pad 1 or Pad 7 may serve as A input; either Pad 3 or Pad 9 as B input. DC blocking capacitors are mandatory on RFC, RF1, and RF2 when using positive control voltages.

Does the HMC240A-SX require external 50 Ω terminations on RF1 and RF2?

No - the HMC240A-SX features reflective "off" states at RF1 and RF2, meaning those ports present an open circuit (not 50 Ω) when unselected. This eliminates the need for external 50 Ω resistors or terminations, reducing PCB area and component count in compact RF modules.

What is the maximum RF input power the HMC240A-SX can handle?

The HMC240A-SX supports +34 dBm RF input power for frequencies between 0.5–4 GHz under –5/0 V control, and +27 dBm below 0.5 GHz. These ratings assume proper thermal management and grounding per the die-mounting guidelines; exceeding them risks permanent GaAs MESFET degradation.

How is the HMC240A-SX packaged and handled?

The HMC240A-SX is supplied as an ESD-sensitive bare die in Gel-Pak® (GP-5) or waffle-pack containers. It must be stored in dry nitrogen after opening, mounted with conductive epoxy on a flat surface, and wire-bonded using 0.025 mm gold wire at 150°C stage temperature and ≤50 g bonding force.

What is the significance of Pads 4 and 6 on the HMC240A-SX die?

Pads 4 and 6 are dedicated AC ground terminals and must be connected to a low-inductance RF/DC ground plane. They provide critical return current paths for RF signals and stabilize impedance matching across DC–4 GHz; failure to bond both results in degraded isolation and return loss performance.