Analog Devices Inc. HMC253LC4TR

Overview

HMC253LC4TR from Analog Devices (formerly Hittite Microwave) is a GaAs MMIC SP8T non-reflective RF switch in a 4×4 mm ceramic SMT package, operating from DC to 3.5 GHz with 1.2 dB typical insertion loss, 35 dB isolation at 2 GHz, and TTL/CMOS-compatible 3-bit control (A/B/C) enabling single +5 V supply operation. It serves as a compact path selector in multi-antenna cellular infrastructure front-ends.

For engineers reviewing the HMC253LC4TR datasheet, HMC253LC4TR pinout, HMC253LC4TR application, or HMC253LC4TR equivalent, key selection criteria include its non-reflective topology, integrated 3:8 decoder, DC–3.5 GHz bandwidth, +24 dBm input P1dB, and RoHS-compliant 24-pin leadless ceramic package - all critical for high-isolation, low-loss RF signal routing in base station transceivers.

Technical Context

The HMC253LC4TR implements a monolithic GaAs-based SP8T architecture with on-die 3:8 TTL/CMOS decoder, eliminating external logic and reducing control lines to three (CTLA, CTLB, CTLC). Its non-reflective design ensures matched 50 Ω impedance in both "on" and "off" states across DC–3.5 GHz, minimizing system-level VSWR degradation during switching.

It operates with a single +5 V ±10% supply (6 mA typical Idd), supports –40°C to +85°C ambient operation, and requires DC blocking capacitors at all RF ports (RFC, RF1–RF8). Switching speed is characterized by 30 ns tRISE/tFALL and 100 ns tON/tOFF under 50% control-to-RF transition.

Key Specifications

Pinout & Package

Ceramic 4×4 mm surface-mount package (alumina body, gold-over-nickel plating, MSL3), 24-pad leadless design with exposed ground paddle requiring solder connection to PCB RF ground plane.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SP8T RF switch applications.

Compared with QM11036 and MASW-011120, the HMC253LC4TR delivers superior isolation at 3.5 GHz, eliminates external decoding logic, and operates from a single +5 V rail - making it optimal for space-constrained, high-reliability cellular infrastructure designs where signal integrity and supply simplicity are prioritized.

Availability

HMC253LC4TR is available at Aetrix Electronics and suitable for cellular infrastructure, fixed wireless access, CATV distribution, and military communications systems requiring stable component supply, long-term obsolescence management, and traceable sourcing.

Supply support for HMC253LC4TR 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-performance RF/Microwave portfolio into mission-critical communication solutions.

The HMC253LC4TR belongs to Hittite's GaAs MMIC SPnT switch family, engineered specifically for broadband, high-isolation RF path selection in wireless infrastructure and defense electronics.

FAQ

What is the recommended DC blocking capacitor value for HMC253LC4TR RF ports?

100 pF 0402 capacitors are specified in the evaluation board design (PCB #104687) for all RF ports (RFC, RF1–RF8) to maintain broadband 50 Ω matching while blocking DC bias. These values provide low reactance (<0.5 Ω) up to 3.5 GHz and fit the compact 4×4 mm layout. Larger values risk resonance; smaller values increase insertion loss at low frequencies.

Does HMC253LC4TR require external bias sequencing or power-up initialization?

No. The HMC253LC4TR has no power-on reset or initialization sequence. It powers up in a known state (RFCOM to RF1 when all CTL pins are low) and responds immediately to control inputs after Vdd reaches +4.5 V. No external sequencer or firmware handshake is needed - simplifying integration into FPGA- or microcontroller-driven RF subsystems.

Can HMC253LC4TR be used in receive-only (RX) applications without transmit power handling concerns?

Yes. The HMC253LC4TR's non-reflective architecture and 12 dB off-state return loss ensure stable 50 Ω termination across all unused paths, preventing noise figure degradation and LO pulling in sensitive RX chains. Its +24 dBm P1dB headroom also accommodates strong out-of-band blockers common in co-located multi-band receivers.

What is the thermal resistance (θ_JA) of HMC253LC4TR, and how should the ground paddle be soldered?

HMC253LC4TR uses an alumina ceramic package with exposed ground paddle; θ_JA is not explicitly specified but achieves ≤45°C/W with ≥8 thermal vias (0.3 mm diameter, spaced ≤1 mm apart) connecting the paddle to a solid inner-layer ground plane. Reflow profile must follow MSL3 guidelines (peak 260°C), and solder paste coverage on the paddle should exceed 80% to ensure mechanical stability and thermal conduction.

How does the integrated 3:8 decoder in HMC253LC4TR affect timing margins in high-speed TDD systems?

The HMC253LC4TR's internal decoder adds negligible delay: tON/tOFF is 100 ns (50% CTL to 10/90% RF), fully compatible with LTE TDD subframe switching (≥1 ms guard periods). No setup/hold timing constraints apply to CTL inputs beyond standard TTL edge rates, enabling direct connection to FPGA GPIOs without additional timing logic or buffers.