Analog Devices Inc. HMC550ETR

Overview

HMC550ETR from Analog Devices (formerly Hittite Microwave) is a GaAs MMIC SPST failsafe RF switch designed for DC–6 GHz signal routing in battery-powered and low-power RF front-ends. It features 0.7 dB typical insertion loss, +52 dBm input IP3, 200 nA on-state current, failsafe "on" operation when unpowered, and operates from 1.2 V to 5 V supply.

For engineers reviewing the HMC550ETR datasheet, HMC550ETR pinout, HMC550ETR application, or HMC550ETR equivalent, this device is selected for ultra-low-current RF switching in RFID tags, ISM-band portables, automotive telematics, and WiMAX/WiBro transceivers where power-off state integrity and wideband linearity are critical.

Technical Context

The HMC550ETR implements a monolithic GaAs-based reflective SPST topology with failsafe biasing: RF1–RF2 path remains closed (low-loss) when Vdd and Vctl are unpowered. Its control logic accepts CMOS-compatible voltage thresholds (Vctl > 2.9 V for "off", < 2.1 V for "on") across a 1.2–5 V Vdd range.

It delivers broadband RF performance from DC to 6 GHz with 20 dB typical return loss and ≥15 dB isolation below 2 GHz. Switching speed is 40 ns rise/fall and 50 ns turn-on/turn-off, supporting fast TDD and burst-mode applications without external bias sequencing.

Key Specifications

Pinout & Package

SOT-26 plastic package (RoHS-compliant, matte Sn finish, MSL1, 260 °C peak reflow); 6-pin surface-mount outline with exposed thermal pad requiring PCB ground connection per manufacturer layout guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with QM11036 and SKY13370-374LF, the HMC550ETR uniquely combines failsafe "on" behavior, sub-µA on-state current, and +52 dBm IP3 in a single SOT-26 package-making it irreplaceable in battery-powered, safety-aware RF systems where signal continuity during power failure is mandatory.

Availability

HMC550ETR is available at Aetrix Electronics and suitable for RFID tag design, automotive telematics integration, and portable ISM-band equipment requiring stable component supply, long-lifecycle support, and RoHS-compliant sourcing.

Supply support for HMC550ETR 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 analog and RF solutions for communications, defense, and instrumentation markets.

The HMC550ETR belongs to Analog Devices' legacy Hittite GaAs MMIC switch family, engineered specifically for ultra-low-power, failsafe RF signal routing in battery-operated and mission-critical wireless endpoints.

FAQ

What does "failsafe" mean for the HMC550ETR?

The HMC550ETR is failsafe because its RF1–RF2 path remains closed (low-loss "on" state) when Vdd and Vctl are unpowered or at 0 V. This behavior ensures uninterrupted RF signal flow during power loss, brownout, or controller reset-critical in automotive telematics and emergency beacon applications where signal continuity cannot be compromised. The HMC550ETR achieves this via internal GaAs transistor biasing that defaults to conduction without external drive.

Can the HMC550ETR operate from a 1.8 V supply?

Yes, the HMC550ETR supports Vdd from 1.2 V to 5 V, including 1.8 V operation. At 1.8 V, it maintains full RF performance: 0.7 dB typical insertion loss and +52 dBm IP3 remain valid per datasheet specifications. Control logic thresholds scale accordingly-Vctl < 1.0 V enables "on", and > 1.8 V enables "off". This makes the HMC550ETR compatible with modern low-voltage microcontrollers and energy-harvesting systems.

Does the HMC550ETR require external DC blocking capacitors?

Yes, DC blocking capacitors are mandatory at both RF1 and RF2 pins per the HMC550ETR datasheet. The device is DC-coupled internally, so external 100–1000 pF capacitors (depending on lowest operating frequency) must be placed in series with each RF port to prevent DC shorting and ensure proper 50 Ω impedance matching. Omitting them risks damage to connected LNAs or PAs and degrades return loss and isolation performance.

How does the HMC550ETR compare to the HMC550 in terms of packaging and compliance?

The HMC550ETR is the RoHS-compliant, lead-free version of the original HMC550. While both share identical electrical specs and SOT-26 mechanical outline, the HMC550ETR uses 100% matte tin lead finish (vs. Sn/Pb on HMC550), has MSL1 rating with 260 °C peak reflow tolerance, and is marked "550E". Functionally interchangeable in new designs, the HMC550ETR meets global environmental regulations and eliminates Pb contamination risk in high-reliability manufacturing lines.

What is the maximum RF input power the HMC550ETR can handle continuously?

The HMC550ETR supports +34 dBm (2.5 W) maximum RF input power under powered conditions (Vctl = 0/+3.3 V), and +35 dBm hot-switch power level. Its absolute maximum channel temperature is 150 °C, with continuous power dissipation derated above 85 °C (433 mW at 85 °C, decreasing by 6.67 mW/°C). For reliable long-term operation, design margins should limit average RF power to ≤ +27 dBm in ambient temperatures up to +85 °C, especially in enclosed enclosures without forced airflow.