Analog Devices Inc. HMC253ALC4TR

Overview

HMC253ALC4TR from Analog Devices (acquired Hittite Microwave) is a GaAs MIMIC SP8T non-reflective RF switch in a 4×4 mm ceramic SMT package, operating from DC to 3.5 GHz with 1.6 dB typical insertion loss, 34 dB isolation at 3.0 GHz, and TTL/CMOS-compatible 3-bit control (A/B/C), used in cellular infrastructure front-end signal routing.

For engineers reviewing the HMC253ALC4TR datasheet, HMC253ALC4TR pinout, HMC253ALC4TR application, or HMC253ALC4TR equivalent, key selection criteria include non-reflective topology for multi-path VSWR stability, integrated 3:8 decoder reducing control lines, +5 V single-supply operation, and RoHS-compliant ceramic packaging for high-reliability RF systems.

Technical Context

This SP8T switch uses a GaAs monolithic microwave integrated circuit (MIMIC) process with non-reflective topology-each off-state path terminates into 50 Ω, minimizing system VSWR degradation during switching. It integrates a full 3:8 TTL/CMOS decoder, accepting three logic-level inputs (CTLA, CTLB, CTLC) to select one of eight RF paths (RF1–RF8) from common RFC.

DC blocking capacitors are mandatory at all RF ports (RFC, RF1–RF8); bias is applied only to Vdd (Pin 8), while ground pins (1,3,5,7,12,14,16,18,20,21,23) and the exposed paddle must be soldered to PCB RF ground per layout guidelines.

Key Specifications

Pinout & Package

Ceramic 4×4 mm leadless SMT package (alumina body, gold-plated leads and exposed ground paddle); 24-pin configuration with 9 RF ports (RFC, RF1–RF8), 3 control inputs (CTLA, CTLB, CTLC), 1 supply (Vdd), and 11 ground terminals-including bottom paddle requiring solder connection to PCB RF ground.

Key Features

Applications

Equivalent & Alternatives

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

Compared with QM11036 and HMC646A, the HMC253ALC4TR uniquely combines SP8T routing, integrated 3:8 decoder, and non-reflective architecture in a single 4×4 mm package-enabling compact, low-component-count front-ends for multi-band infrastructure where path count and VSWR stability are critical.

Availability

HMC253ALC4TR is available at Aetrix Electronics and suitable for cellular infrastructure, fixed wireless access, and military communications requiring stable component supply, long-term lifecycle assurance, and traceable RoHS-compliant sourcing.

Supply support for HMC253ALC4TR 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 ADI's broader signal chain solutions.

The HMC253ALC4TR belongs to Hittite's GaAs MIMIC SPnT switch product line, designed specifically for wideband, high-isolation, non-reflective signal routing in wireless infrastructure and defense systems.

FAQ

What is the operating temperature range for the HMC253ALC4TR?

The HMC253ALC4TR is specified for continuous operation from –40°C to +85°C ambient temperature. Its GaAs die and ceramic package support reliable performance across this range, with channel temperature rated up to 150°C. Thermal resistance from channel to package paddle is 183°C/W for through paths, making heatsinking via the exposed ground paddle essential in high-power applications. The HMC253ALC4TR maintains specified insertion loss and isolation across this full range.

Does the HMC253ALC4TR require external DC blocking capacitors?

Yes, DC blocking capacitors are mandatory at all RF ports: RFC, RF1 through RF8. The HMC253ALC4TR is DC-coupled internally, and absence of external blocking will cause bias disruption or damage. Recommended values are 100 pF in 0402 package, as validated on the official EV1HMC253ALC4 evaluation board. This requirement applies regardless of whether the port is used in transmit or receive mode, due to the non-reflective termination architecture of the HMC253ALC4TR.

How does the integrated 3:8 decoder simplify system design with the HMC253ALC4TR?

The integrated 3:8 decoder in the HMC253ALC4TR accepts three TTL/CMOS control lines (CTLA, CTLB, CTLC) and directly selects one of eight RF paths-eliminating need for external logic gates or FPGA resources. This reduces PCB area, component count, and routing complexity. With only three control signals and a single +5 V supply, the HMC253ALC4TR enables straightforward interfacing to microcontrollers or baseband processors. No additional decoding ICs or level shifters are needed, unlike discrete SPDT/SP4T implementations.

What is the maximum RF input power the HMC253ALC4TR can handle?

The HMC253ALC4TR supports +25 dBm maximum input power on the through path (RFC ↔ selected RFx) for frequencies 0.5–3.5 GHz, and +23.5 dBm on terminated paths. At lower frequencies (0.05–0.5 GHz), limits are +20 dBm (through) and +20 dBm (terminated). These ratings assume proper thermal management via the exposed ground paddle. The HMC253ALC4TR's 1 dB compression point is 24 dBm typ. at 0.5–3.5 GHz, confirming robust linearity for infrastructure PA driver stages.

Is the HMC253ALC4TR pin-compatible with other Hittite SP8T switches like the HMC252ALC4?

No, the HMC253ALC4TR is not pin-compatible with the HMC252ALC4. While both are 4×4 mm ceramic SP8T switches, the HMC252ALC4 uses a reflective topology and different pin assignments-its control inputs and RF port mapping differ significantly. The HMC253ALC4TR's pinout (e.g., CTLA on Pin 11, Vdd on Pin 8, RFC on Pin 2) is unique to its non-reflective, decoder-integrated architecture. Layout reuse is not possible; redesign is required when substituting the HMC253ALC4TR for any other Hittite SP8T variant.