Analog Devices Inc. HMC595E

Overview

HMC595E from Analog Devices (formerly Hittite Microwave) is a GaAs MMIC SPDT transmit/receive switch designed for RF front-end signal routing in cellular/3G infrastructure and WiMAX/WiBro systems. It operates from DC to 3 GHz, delivers 0.3 dB typical insertion loss at 2 GHz, supports +65 dBm input IP3 at +8 V bias, and handles up to 3 W RF power with positive CMOS/TTL-compatible control (0/+3 V to 0/+10 V).

For engineers reviewing the HMC595E datasheet, HMC595E pinout, HMC595E application, or HMC595E equivalent, this page provides verified specifications, SOT26 package layout, real-world use cases in automotive telematics and test equipment, and validated alternative parts for T/R switching in high-linearity, high-power RF paths.

Technical Context

The HMC595E implements a reflective GaAs MMIC architecture where RF1 and RF2 present short-circuit terminations when off, enabling low-loss T/R switching without external termination resistors. Its control logic uses dual CMOS/TTL-compatible inputs (A/B) with defined low/high voltage thresholds (0–0.2 V / +3–+8 V), supporting direct interface to logic families without level-shifting.

Thermal design is constrained by 173 °C/W junction-to-ambient thermal resistance and 150 °C max channel temperature; continuous dissipation is limited to 380 mW at +85 °C (derated 6 mW/°C above). DC blocking capacitors are mandatory at RFC, RF1, and RF2 ports to prevent bias disruption and ensure proper RF matching.

Key Specifications

Pinout & Package

Package: RoHS-compliant SOT26 (6-lead), matte tin-plated copper alloy leadframe, MSL1 rating, 260 °C peak reflow. Dimensions per Hittite outline drawing: 2.9 mm × 1.6 mm × 1.1 mm.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SPDT T/R switching applications.

Compared with HMC195E and QM11036, the HMC595E delivers superior linearity (+65 dBm vs. +58/+55 dBm) and faster switching (120 ns vs. N/A/500 ns) in a proven GaAs process, making it optimal for infrastructure-grade T/R paths demanding both dynamic range and timing fidelity.

Availability

HMC595E is available at Aetrix Electronics and suitable for cellular infrastructure, WiMAX base stations, and automotive telematics requiring stable component supply, long-term lifecycle support, and traceable GaAs MMIC sourcing.

Supply support for HMC595E 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 ADI's broader signal chain solutions.

The HMC595E belongs to Hittite's legacy GaAs MMIC switch family, engineered specifically for high-power, high-linearity T/R switching in wireless infrastructure and test instrumentation.

FAQ

What is the maximum RF input power the HMC595E can handle without damage?

The HMC595E has an absolute maximum RF input power rating of 39 dBm (8 W) at 0.5–2.5 GHz when biased at 0/+8 V. This rating assumes proper DC blocking at all RF ports and adherence to thermal limits-continuous dissipation must not exceed 380 mW at +85 °C ambient, with derating applied above that temperature. Exceeding these conditions risks permanent GaAs die degradation.

Does the HMC595E require external DC blocking capacitors, and why?

Yes, the HMC595E requires external DC blocking capacitors at RFC, RF1, and RF2 ports because all three RF terminals are DC-coupled and internally biased. Without blocking, DC paths would disrupt system-level bias networks and compromise 50 Ω impedance matching. Capacitor value determines the low-frequency cutoff-e.g., a 330 pF capacitor sets f_low ≈ 10 MHz for 50 Ω systems-and is specified in the evaluation board design (PCB #101659).

How does the HMC595E achieve 30 dB isolation while using a reflective switch architecture?

The HMC595E achieves 30 dB isolation through precise GaAs MMIC layout and impedance tuning that forces high-reflection phase cancellation between RFC and the off-state port (RF1 or RF2). Unlike absorptive switches, it relies on controlled open/short terminations rather than 50 Ω loads-verified by measured RF1-to-RF2 isolation plots showing ≥24 dB from DC to 2.5 GHz. This architecture eliminates termination resistor losses and heat generation.

Can the HMC595E be driven directly by standard CMOS logic, and what voltage levels are supported?

Yes, the HMC595E control inputs A and B accept direct drive from HC/HCT CMOS logic families. The device defines "Low" as 0–0.2 Vdc at 10 µA and "High" as +3 Vdc (2 µA typical) to +8 Vdc (40 µA typical), with ±0.2 V tolerance. This allows seamless interface to +3.3 V or +5 V logic without level shifters-though +8 V bias yields best RF performance (higher P1dB and IIP3).

What is the thermal resistance and maximum junction temperature specification for the HMC595E?

The HMC595E has a thermal resistance of 173 °C/W (junction-to-ambient) and a maximum channel temperature of 150 °C. Its continuous power dissipation is rated at 380 mW at +85 °C ambient, decreasing linearly by 6 mW per °C above that point. To maintain reliability, PCB layout must solder all ground leads (pins 2, and package bottom) directly to a low-impedance RF ground plane per Hittite's recommended land pattern.