Analog Devices Inc. HMC344LP3

Overview

HMC344LP3 from Analog Devices (formerly Hittite Microwave) is a GaAs MMIC SP4T non-reflective RF switch operating from DC to 8 GHz, delivering 1.8 dB typical insertion loss and 40 dB isolation at 6 GHz, with integrated 2:4 TTL decoder and negative 0/–5 V control logic-used in broadband signal routing for fiber-optic transceivers and switched filter banks.

For engineers reviewing the HMC344LP3 datasheet, HMC344LP3 pinout, HMC344LP3 application, or HMC344LP3 equivalent, key selection criteria include its non-reflective architecture, –5 V fixed bias requirement, 3×3 mm QFN package with exposed paddle, DC–8 GHz bandwidth, and TTL-compatible dual-control interface reducing external logic complexity.

Technical Context

The HMC344LP3 implements a GaAs MESFET-based SP4T architecture with on-die binary decoder, enabling four RF paths (RF1–RF4) to be selected via two TTL-level control inputs (CTLA, CTLB). Its non-reflective design terminates all off-state ports into 50 Ω, minimizing system VSWR impact across DC–8 GHz.

It requires a fixed –5 V ±10% supply (Vee) and operates with 0/–5 V control logic; switching speed is characterized by 35 ns rise/fall time and 150 ns turn-on/turn-off delay. Thermal resistance of the insertion-loss path is 143 °C/W, supporting operation from –40 °C to +85 °C.

Key Specifications

Pinout & Package

Package: 16-lead 3×3 mm QFN with exposed metal thermal paddle (MSL1, Sn/Pb finish); requires soldering of all ground leads and paddle to PCB RF ground per Hittite land pattern guidelines.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SP4T RF switch applications.

Compared with HMC344LP3, HMC349ALP4CE trades non-reflective operation for lower loss and requires external terminations, while QM11036 avoids negative bias but adds external decode logic and sacrifices isolation-making HMC344LP3 optimal for compact, high-isolation, self-contained DC–8 GHz routing.

Availability

HMC344LP3 is available at Aetrix Electronics and suitable for fiber-optic transceivers, wireless infrastructure filter banks, and broadband spectrum monitoring requiring stable component supply and guaranteed long-term availability.

Supply support for HMC344LP3 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 maintains its high-frequency RF portfolio, specializing in microwave/mmWave ICs for defense, communications, and instrumentation.

The HMC344LP3 belongs to Hittite's legacy GaAs MMIC SPnT switch family, designed specifically for broadband non-reflective signal routing in test equipment, fiber optics, and wireless infrastructure where impedance stability is critical.

FAQ

What is the control voltage logic scheme used by the HMC344LP3?

The HMC344LP3 uses negative-voltage TTL-compatible control logic: CTLA and CTLB accept 0 V (logic high) and –5 V (logic low) inputs, with internal level-shifting to drive GaAs FET gates. The integrated 2:4 decoder interprets the two-bit combination to select RF1–RF4 per the truth table; no external logic is required. This scheme ensures compatibility with standard digital controllers when paired with a –5 V bias rail.

Does the HMC344LP3 require external termination resistors for off-state ports?

No, the HMC344LP3 is a non-reflective SP4T switch with on-die 50 Ω terminations for all off-state RF ports. This eliminates the need for external resistors and maintains consistent 50 Ω system impedance regardless of switching state-critical for minimizing VSWR in sensitive RF measurement and communication systems using the HMC344LP3.

What is the maximum RF input power the HMC344LP3 can handle continuously?

The HMC344LP3 supports +24 dBm maximum input power (absolute rating) and delivers 17–21 dBm typical input power for 1 dB compression across 0.5–8 GHz. Its thermal resistance of 143 °C/W on the insertion-loss path enables reliable continuous-wave operation at +20 dBm within the –40 °C to +85 °C ambient range when properly mounted with the exposed paddle soldered to PCB ground.

Can the HMC344LP3 operate with a positive-only supply system?

No-the HMC344LP3 requires a fixed –5 V ±10% bias supply (Vee) and negative control voltages (0/–5 V), making it incompatible with positive-only supply architectures. Systems lacking negative rails must add a charge-pump or inverting DC/DC converter to generate Vee; alternative devices like Qorvo QM11036 or Mini-Circuits ZASWA-2-50DR+ offer positive-control SP4T functionality without negative bias.

How does the HMC344LP3's 3×3 mm QFN package affect PCB layout and thermal performance?

The HMC344LP3's 3×3 mm QFN package features an exposed metal paddle that must be soldered to a large PCB ground plane for both electrical return and thermal dissipation. Per Hittite's land pattern guidance, all ground leads (pins 5, 14, 16) and the paddle must connect directly to RF ground; failure to do so degrades isolation, increases insertion loss, and risks thermal runaway under high-power operation of the HMC344LP3.