Analog Devices Inc. 101675-HMC595

Overview

HMC595 from Analog Devices (formerly Hittite Microwave) is a GaAs MMIC SPDT T/R switch designed for RF front-end signal routing in cellular/3G infrastructure and WiMAX transceivers. It operates from DC to 3 GHz, delivers 0.3 dB typical insertion loss at 1 GHz, provides 30 dB isolation, handles +39 dBm hot-switching power at +8 V control, and uses positive CMOS/TTL-compatible control voltages (0/+3 V to 0/+10 V).

For engineers reviewing the HMC595 datasheet, HMC595 pinout, HMC595 application, or HMC595 equivalent, this device is selected for high-linearity T/R switching where low distortion, 3 W RF power handling, and SOT26 footprint are critical - especially in compact wireless infrastructure and test equipment designs requiring stable performance across -40°C to +85°C.

Technical Context

The HMC595 implements a reflective GaAs MMIC architecture with RFC, RF1, and RF2 ports configured as single-pole double-throw (SPDT) paths. Control inputs A and B operate in complementary logic states (High/Low) to select RFC→RF1 or RFC→RF2, with RF1 and RF2 presenting reflective shorts when off.

It features DC-coupled 50 Ω RF ports requiring external DC blocking capacitors, supports bias voltages from +3 V to +10 Vdc, and achieves +65 dBm input IP3 and +37 dBm P1dB at +8 V - enabling high-dynamic-range operation in transmit/receive duplexing without external amplification.

Key Specifications

Pinout & Package

SOT26 package (6-lead, ultra-small surface-mount), RoHS-compliant version HMC595E uses matte Sn finish; moisture sensitivity level MSL1; max reflow 260 °C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with HMC195E and QM11036, the HMC595 delivers superior third-order linearity (+65 dBm IP3) and higher hot-switching power (+39 dBm), making it the preferred choice for infrastructure-class T/R switching where signal integrity and power robustness are non-negotiable.

Availability

HMC595 is available at Aetrix Electronics and suitable for cellular infrastructure, WiMAX subscriber units, and automotive telematics requiring stable component supply, long-lifecycle support, and traceable sourcing.

Supply support for HMC595 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, Inc. (acquired Hittite Microwave in 2014) is a global leader in high-performance analog, RF, and mixed-signal semiconductors for communications, defense, and instrumentation markets.

The HMC595 belongs to Analog Devices' legacy Hittite GaAs MMIC switch product line, engineered specifically for high-linearity, high-power T/R switching in wireless infrastructure and test equipment where distortion and thermal stability are critical.

FAQ

What is the maximum RF input power the HMC595 can handle during hot switching?

The HMC595 supports +39 dBm hot-switching RF input power at 0.5–2.5 GHz when biased at +8 Vdc. This corresponds to 3 W incident power, verified under continuous switching conditions. The HMC595 datasheet specifies this rating in its Absolute Maximum Ratings table, and operation beyond this level risks permanent GaAs FET degradation. Always use DC blocking capacitors at RFC, RF1, and RF2 to prevent DC path damage.

Does the HMC595 require external DC blocking capacitors, and why?

Yes, the HMC595 requires external DC blocking capacitors at all three RF ports (RFC, RF1, RF2) because its RF path is DC-coupled and internally matched to 50 Ω. Without DC blocks, any DC offset or bias voltage from connected components (e.g., PA output or LNA input) could forward-bias internal GaAs junctions, causing failure. Capacitor value determines lowest usable frequency - e.g., 330 pF enables operation down to ~10 MHz.

What is the difference between HMC595 and HMC595E?

The HMC595 uses Sn/Pb lead finish and has a 235 °C max reflow temperature, while the HMC595E is RoHS-compliant with 100% matte Sn finish and supports 260 °C reflow. Both share identical electrical specifications, SOT26 package dimensions, and pinout. The HMC595E replaces HMC595 in new designs requiring lead-free manufacturing; no circuit or layout changes are needed for migration.

Can the HMC595 be controlled directly by standard CMOS logic outputs?

Yes, the HMC595 control inputs A and B accept standard CMOS logic levels: Low = 0–0.2 Vdc (≤10 µA), High = +3 to +8 Vdc (≤40 µA). It is compatible with HC, HCT, and AC-series logic without level shifters. For best linearity, +8 Vdc is recommended; for lower power consumption, +3 Vdc is functional but reduces P1dB and IP3 by ~8 dB.

What is the thermal resistance and maximum channel temperature of the HMC595?

The HMC595 has a thermal resistance of 173 °C/W and a maximum channel temperature of 150 °C. At +85 °C ambient, its continuous power dissipation is limited to 0.38 W (derated by 6 mW/°C above 85 °C). Proper PCB layout - including direct soldering of pins 2 (GND) and the package bottom to a solid RF ground plane - is essential to maintain thermal performance and avoid thermal runaway during high-power operation.