Analog Devices Inc. HMC245QS16ETR

Overview

HMC245QS16ETR from Analog Devices (formerly Hittite Microwave) is a GaAs MMIC SP3T non-reflective RF switch operating from DC to 3.5 GHz, delivering 0.5 dB insertion loss at 2.0 GHz, 40 dB isolation at 1.0 GHz, and integrated TTL/CMOS-compatible 2:3 decoder requiring only two control lines and +5 V bias - used in basestation infrastructure RF front-end path selection.

For engineers reviewing the HMC245QS16ETR datasheet, HMC245QS16ETR pinout, HMC245QS16ETR application, or HMC245QS16ETR equivalent, key selection criteria include non-reflective termination for broadband impedance stability, single-supply +5 V operation, 16-lead QSOP package compatibility with RF layout constraints, and all-off isolation state for system-level signal integrity assurance.

Technical Context

The HMC245QS16ETR implements a monolithic GaAs MMIC architecture with integrated DC-coupled 50 Ω RF ports (RFC, RF1–RF3), non-reflective termination on all off-state paths, and on-die 2:3 decoder logic that translates dual TTL/CMOS inputs (A/B) into three RF path selections plus an "all off" state. It operates across -40 °C to +85 °C with thermal resistance of 210 °C/W on insertion loss path.

Control interface uses standard TTL voltage thresholds (low ≤ 0.8 V, high ≥ 2.0 V), draws only 3.0 mA typical supply current at +5 V, and supports fast switching with 40 ns rise/fall time and 150 ns turn-on/turn-off delay - enabling time-division duplexing and antenna diversity sequencing in sub-3.5 GHz wireless systems.

Key Specifications

Pinout & Package

Package: 16-lead QSOP (Quad Small Outline Package), RoHS-compliant, matte tin-plated leadframe, MSL1 rating, max reflow 260 °C.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SP3T RF switch applications.

Compared with HMC547LP3E and QM11036, the HMC245QS16ETR uniquely balances DC–3.5 GHz coverage, 40 dB isolation, non-reflective termination, and true all-off functionality within a single +5 V, 16-pin QSOP footprint - making it optimal for infrastructure-grade RF path control where reliability and broadband match are prioritized over extreme bandwidth or lowest cost.

Availability

HMC245QS16ETR is available at Aetrix Electronics and suitable for basestation infrastructure, CATV/DBS distribution, wireless local loop, and RF test equipment requiring stable component supply and long-term lifecycle support.

Supply support for HMC245QS16ETR 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. is a global leader in high-performance analog, mixed-signal, and RF ICs, formed through acquisition of Hittite Microwave in 2014 to strengthen its RF and microwave portfolio.

The HMC245QS16ETR belongs to Hittite's legacy GaAs MMIC SP3T switch product line, designed specifically for broadband non-reflective RF path selection in wireless infrastructure and test instrumentation where DC coupling, low loss, and high isolation are essential.

FAQ

What is the maximum RF input power the HMC245QS16ETR can handle without compression?

The HMC245QS16ETR supports +27 dBm maximum input power from 0.5–3.5 GHz and +20 dBm from 0.05–0.5 GHz. At 2.0 GHz, its 1 dB compression point is +23 dBm (typical), meaning the HMC245QS16ETR maintains linear operation up to this level before insertion loss increases by 1 dB - critical for preserving signal fidelity in high-power transmit paths.

Does the HMC245QS16ETR require external termination resistors for off-state ports?

No, the HMC245QS16ETR features a non-reflective internal termination architecture. All off-state RF ports (RF1–RF3) are terminated to 50 Ω on-die, eliminating the need for external shunt resistors. This ensures consistent VSWR and return loss across frequency, simplifying PCB layout and improving broadband matching - a key advantage of the HMC245QS16ETR over reflective switch alternatives.

What is the function of the "All Off" state in the HMC245QS16ETR truth table?

When control inputs A and B are both high (A=H, B=H), the HMC245QS16ETR enters the "All Off" state: RFC is disconnected from RF1, RF2, and RF3 simultaneously, and all three RF ports are terminated to 50 Ω. This provides >26 dB isolation up to 3.5 GHz and enables safe RF muting during calibration, fault recovery, or system initialization - a safety-critical feature not present in basic SP3T switches.

Can the HMC245QS16ETR operate with CMOS logic levels, or is it strictly TTL-compatible?

The HMC245QS16ETR accepts both TTL and CMOS logic levels: low input is defined as 0–0.8 V (≤5 µA leakage), high input as 2.0–5.0 V (≤70 µA leakage). Since standard CMOS outputs (e.g., from FPGAs or microcontrollers) typically swing rail-to-rail (0 V / +5 V), they fully satisfy the HMC245QS16ETR's control voltage requirements - confirming direct interoperability without level-shifting circuitry.

What is the thermal resistance of the HMC245QS16ETR, and how does it impact PCB layout?

The HMC245QS16ETR has a thermal resistance of 210 °C/W on the insertion loss path and 250 °C/W on terminated paths. To maintain junction temperature below 150 °C under +27 dBm input, the PCB must provide robust thermal conduction: all ground pins (2–5, 7, 11, 13, 15, 16) must be soldered directly to a solid RF ground plane, and thermal vias should be placed beneath the package body - a requirement explicitly stated in the HMC245QS16ETR datasheet.