Analog Devices Inc. HMC545ETR

Overview

HMC545ETR from Analog Devices (formerly Hittite Microwave) is a GaAs MMIC SPDT RF switch designed for DC–3 GHz signal routing in RF front-ends. It delivers 0.25 dB typical insertion loss at 1 GHz, +65 dBm input IP3 at 0/+5 V control, and operates with positive CMOS/TTL-compatible control voltages (0/+3 V to 0/+8 V). Its primary role is high-isolation, low-loss path selection in cellular infrastructure and portable wireless transceivers.

For engineers reviewing the HMC545ETR datasheet, HMC545ETR pinout, HMC545ETR application, or HMC545ETR equivalent, this page provides verified electrical specs, SOT26 package details, truth table–based switching behavior, thermal limits (−40°C to +85°C), and real-world alternatives for RF switch selection in IF/RF filter and receiver switching circuits.

Technical Context

The HMC545ETR implements a reflective GaAs MMIC architecture where RF1 and RF2 present reflective shorts when "Off", minimizing external termination needs. Its control logic uses two independent CMOS/TTL-compatible inputs (A and B) with 0.5 µA typical high-state current draw and ±0.2 Vdc tolerance.

It supports three control voltage ranges (0/+3 V, 0/+5 V, 0/+8 V), directly impacting linearity: input P1dB rises from +23 dBm to +32 dBm and IP3 reaches +65 dBm at 0/+5 V and 0/+8 V. Switching speed is fixed at 70 ns tRISE/tFALL and 90 ns tON/tOFF across DC–3 GHz.

Key Specifications

Pinout & Package

Package: SOT26 (6-lead plastic, RoHS-compliant, matte Sn finish, MSL1, max reflow 260°C). Ground leads (Pins 1, 3, 5) must be soldered to PCB RF ground per layout guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with QM11036 and SKY13370-374LF, the HMC545ETR uniquely balances DC–3 GHz bandwidth, ultra-low loss, and +65 dBm IP3 in a proven SOT26 package-making it optimal for 3G/WiMAX infrastructure and automotive telematics where both linearity and thermal stability are non-negotiable.

Availability

HMC545ETR is available at Aetrix Electronics and suitable for cellular infrastructure, WLAN front-ends, and automotive telematics applications requiring stable component supply, long-lifecycle support, and RoHS-compliant sourcing.

Supply support for HMC545ETR 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 RF signal chain solutions for communications, defense, and instrumentation markets.

The HMC545ETR belongs to Analog Devices' legacy Hittite GaAs MMIC switch family, engineered specifically for low-loss, high-linearity RF path control in infrastructure and portable wireless systems operating up to 3 GHz.

FAQ

What is the maximum RF input power the HMC545ETR can handle without damage?

The HMC545ETR has an absolute maximum RF input power rating of +34 dBm when control voltage is set to 0/+8 V. This hot-switch power level assumes proper DC blocking at all RF ports (RFC, RF1, RF2) and operation within the −40°C to +85°C temperature range. Exceeding +34 dBm risks permanent GaAs die degradation. For reliable continuous operation, design to the +32 dBm hot-switch limit specified in the datasheet.

Does the HMC545ETR require external DC blocking capacitors, and why?

Yes, the HMC545ETR requires external DC blocking capacitors at RFC, RF1, and RF2 because all three RF ports are DC-coupled and internally biased. Without these capacitors, DC voltage from preceding or following stages would disrupt the internal GaAs FET bias network, causing malfunction or damage. Capacitor value determines the low-frequency cutoff-e.g., 330 pF yields ~10 MHz lower limit in a 50 Ω system.

How does control voltage affect linearity performance in the HMC545ETR?

Increasing control voltage from 0/+3 V to 0/+5 V and 0/+8 V directly improves linearity: input P1dB rises from +23 dBm to +29 dBm to +32 dBm, and input IP3 increases from +45 dBm to +65 dBm. This occurs because higher gate drive enhances channel conductivity and reduces nonlinear distortion. For best linearity in 3G/WiMAX receivers, operate HMC545ETR at 0/+5 V or 0/+8 V.

Can the HMC545ETR be used in a transmit path with high output power?

Yes-the HMC545ETR supports transmit-path use with up to +32 dBm hot-switch power at 0/+8 V control. Its reflective OFF-state design means RF1 and RF2 present shorts when inactive, eliminating need for external 50 Ω terminations. However, ensure all RF ports have DC blocking and that PCB layout maintains 50 Ω impedance and solid ground connections to avoid power compression or instability.

What is the thermal resistance and power dissipation limit of the HMC545ETR?

The HMC545ETR has a thermal resistance of 282 °C/W and a maximum continuous power dissipation of 0.23 W at +85°C ambient. Above +85°C, power must be derated by 3.5 mW/°C. This thermal profile supports operation in sealed enclosures or automotive under-hood environments when mounted on a 2-layer PCB with adequate copper pour and thermal vias beneath Pin 2 (GND) and the exposed paddle (if applicable).