Analog Devices Inc. HMC347A-SX

Overview

HMC347A-SX from Analog Devices is a GaAs pHEMT monolithic microwave SPDT switch operating from 0.1 GHz to 20 GHz, delivering <2.0 dB insertion loss and >40 dB isolation across full bandwidth, with nonreflective 50 Ω design for test instrumentation and military radar front-ends.

For engineers reviewing the HMC347A-SX datasheet, HMC347A-SX pinout, HMC347A-SX application, or HMC347A-SX equivalent, key selection criteria include broadband RF switching performance, negative-only control voltage operation (−5 V/0 V), high linearity (P1dB = 29 dBm, IP3 = 45 dBm), and bare-die thermal management requirements.

Technical Context

The HMC347A-SX implements on-chip via-hole structures enabling nonreflective 50 Ω termination of the off-state path, supporting bidirectional RF signal routing between RFC and either RF1 or RF2. It requires no external supply-only two negative digital control inputs (CTRLA/CTRLB) defining SPDT state via −5 V/0 V logic levels.

Its die-level construction (1.22 mm × 0.85 mm × 0.1 mm, C-10-9 package) mandates direct backside metallization to RF ground using AuSn eutectic or conductive epoxy, with microstrip transmission lines recommended for minimal bond length (≤3 mil ribbon).

Key Specifications

Pinout & Package

Package: 10-pad bare die (C-10-9), dimensions 1.22 mm × 0.85 mm × 0.1 mm, backside metallized for direct RF grounding.

Key Features

Applications

Equivalent & Alternatives

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

Compared with HMC347LP3E, the HMC347A-SX eliminates supply dependency and offers superior linearity but demands custom die attach; versus QM11036, it delivers higher power handling and isolation at the cost of tighter thermal design constraints and higher unit price.

Availability

HMC347A-SX is available at Aetrix Electronics and suitable for test instrumentation, military radar, microwave radio, and broadband telecom infrastructure requiring stable component supply and traceable sourcing of high-reliability GaAs MMIC switches.

Supply support for HMC347A-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 is a global leader in high-performance analog, mixed-signal, and RF ICs, serving precision instrumentation, communications, and defense markets since 1965.

The HMC347A-SX belongs to the Hittite Microwave product line (acquired by Analog Devices in 2014), engineered specifically for broadband, high-linearity, nonreflective RF switching in demanding microwave and millimeter-wave systems.

FAQ

What is the control voltage requirement for reliable operation of the HMC347A-SX?

The HMC347A-SX requires two negative control voltages: CTRLA and CTRLB must be driven to −5 V (logic high) or 0 V (logic low) with ≤10 µA input current. The device draws no supply current and operates without any positive or negative power rail beyond these control signals. This configuration ensures correct SPDT state selection per the truth table in the datasheet, and deviation outside −5 V to 0 V risks undefined switching behavior or degraded isolation.

Does the HMC347A-SX require DC blocking capacitors on its RF ports?

Yes, DC blocking capacitors are required on RF1, RF2, and RFC pads if the connected RF line potential differs from 0 V, because all three RF pads are dc-coupled. The HMC347A-SX does not integrate internal blocking; omission risks bias disruption or damage when interfacing with biased LNAs or PAs. When the RF line is at 0 V DC, no blocking is needed-confirmed by the "dc-coupled and matched to 50 Ω" specification in the pin descriptions.

How is thermal management handled for the HMC347A-SX in high-power operation?

The HMC347A-SX die bottom must be directly bonded to an RF ground plane using AuSn eutectic preforms or electrically conductive epoxy to achieve effective thermal conduction. Its θJC is 118 °C/W (through path) and 200 °C/W (terminated path). For continuous 27 dBm operation, PCB copper area, thermal vias, and substrate material (e.g., 5 mil alumina) must be designed per the mounting guidelines in the datasheet to keep junction temperature below 150°C.

Can the HMC347A-SX be used in bidirectional RF signal paths?

Yes, the HMC347A-SX is fully bidirectional: RF signals may be applied to RFC while RF1/RF2 serve as outputs, or applied to RF1/RF2 while RFC serves as output. This is explicitly stated in the Theory of Operation section and validated by symmetric insertion loss and return loss data across all ports. No internal diode asymmetry or directional biasing exists-the device functions identically in either direction when control logic and thermal conditions are met.

What is the meaning of "HMC347A-SX" in the ordering nomenclature?

"HMC347A-SX" denotes the sample-order variant of the HMC347A bare-die switch, sharing identical electrical specifications, package (C-10-9), and temperature range (−55°C to +85°C) with the production-grade HMC347A. The "-SX" suffix indicates it is distributed as a non-recurring engineering (NRE) sample for evaluation and qualification-fully functional and representative of production units, but subject to different minimum order quantities and lead times than standard orders.