Analog Devices Inc. 101673-HMC252QS24

Overview

HMC252QS24 from Analog Devices (formerly Hittite Microwave) is a GaAs MMIC SP6T non-reflective RF switch operating from DC to 3 GHz, featuring 0.9 dB typical insertion loss at 2 GHz, integrated 3:6 TTL decoder, and single +5 V or +3.3 V supply-used in base station transmit/receive path switching.

For engineers reviewing the HMC252QS24 datasheet, HMC252QS24 pinout, HMC252QS24 application, or HMC252QS24 equivalent, key selection criteria include non-reflective architecture, TTL/CMOS-compatible control, 24-lead QSOP package, and DC–3 GHz broadband performance with <1.3 dB max insertion loss up to 3 GHz.

Technical Context

The HMC252QS24 implements a monolithic GaAs MMIC design with integrated 3:6 decoder logic, enabling full SP6T path selection using only three TTL/CMOS control lines (A, B, C) and a single positive bias rail. It operates in non-reflective mode: all RF ports are terminated when deselected, minimizing system VSWR impact during state transitions.

It supports dual supply operation (+3.3 V or +5 V), with corresponding I_DD of 4.8 mA or 5 mA (typical), and delivers 21–24 dBm input P1dB compression across 0.3–3.0 GHz. Thermal resistance is 117 °C/W on the insertion-loss path, supporting reliable operation from –40 °C to +85 °C.

Key Specifications

Pinout & Package

Package: 24-lead QSOP (Quad Small Outline Package), RoHS-compliant variant marked HMC252QS24E; body material is low-stress injection-molded plastic with Sn/Pb (HMC252QS24) or 100% matte Sn (HMC252QS24E) lead finish; MSL1 rating.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SP6T RF switch applications.

Compared with HMC252QS24, HMC547LP3E reduces complexity for dual-path systems but cannot replace 6-throw functionality, while QM11036 extends frequency range but adds layout and logic design overhead due to missing on-die decoder and QFN thermal constraints.

Availability

HMC252QS24 is available at Aetrix Electronics and suitable for base station infrastructure, CATV/DBS headend systems, and wireless LAN access point designs requiring stable component supply, long-lifecycle support, and consistent RF performance across production batches.

Supply support for HMC252QS24 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 GaAs, GaN, and SiGe MMIC solutions for communications and defense markets.

The HMC252QS24 belongs to Hittite's legacy SPnT non-reflective switch family, designed specifically for broadband RF signal routing in infrastructure equipment where low loss, high isolation, and TTL simplicity are critical.

FAQ

What is the maximum operating frequency of the HMC252QS24?

The HMC252QS24 is specified for continuous operation from DC to 3.0 GHz. Insertion loss remains ≤1.3 dB and isolation ≥26 dB across this full band under +5 V bias at +25 °C. Performance is validated per datasheet Electrical Specifications I and II, with measured curves confirming flat response through 3 GHz.

Does the HMC252QS24 require external DC blocking capacitors?

Yes, the HMC252QS24 requires external DC blocking capacitors at RFC and all RF1–RF6 ports, as stated in the Truth Table note. This is mandatory because the device lacks internal DC blocking; omission risks bias disruption and RF port damage. Typical values used on evaluation board 101673 are 100 pF (0402).

Can the HMC252QS24 operate with both +3.3 V and +5 V supplies?

Yes, the HMC252QS24 supports dual supply operation: +3.3 V (±5%) and +5.0 V (±10%). Each voltage has corresponding I_DD specs (4.8 mA / 5 mA typ.) and TTL threshold definitions. Control logic levels scale accordingly-no external level shifting is needed for either rail.

What is the meaning of "non-reflective" in the HMC252QS24 datasheet?

"Non-reflective" means that all six RF output ports (RF1–RF6) are internally 50 Ω terminated when deselected. Unlike reflective switches, this prevents open-circuit or short-circuit conditions at unused ports, maintaining system impedance match and minimizing VSWR degradation during switching-critical in cascaded RF stages.

Is the HMC252QS24 pin-compatible with the HMC252QS24E?

Yes, the HMC252QS24 and HMC252QS24E share identical pinout, footprint, and electrical specifications. The only differences are RoHS compliance (matte Sn vs. Sn/Pb plating), peak reflow temperature (260 °C vs. 235 °C), and MSL1 handling-both are mechanically and electrically interchangeable in existing designs.