Analog Devices Inc. HMC245QS16E

Overview

HMC245QS16E from Analog Devices is a GaAs MMIC SP3T non-reflective RF switch in 16-lead QSOP package, operating from DC to 3.5 GHz with 0.7 dB insertion loss at 2.0 GHz, 40 dB isolation at 1.0 GHz, and integrated 2:3 TTL/CMOS decoder requiring only two control lines and +5 V bias - used in basestation infrastructure RF front-end path selection.

For engineers reviewing the HMC245QS16E datasheet, HMC245QS16E pinout, HMC245QS16E application, or HMC245QS16E equivalent, key selection criteria include non-reflective termination behavior, all-off isolation state, temperature-stable RF performance from –40°C to +85°C, and compatibility with 50 Ω system impedance and standard TTL logic levels.

Technical Context

The HMC245QS16E implements a monolithic GaAs-based SP3T architecture with internal DC blocking on all RF ports (RFC, RF1–RF3), enabling direct-coupled 50 Ω interface without external DC blocks in most configurations. Its non-reflective design terminates off-state paths to 50 Ω, minimizing signal reflections during switching transitions.

Integrated 2:3 decoder logic accepts TTL/CMOS-compatible A/B inputs (0–0.8 V low, 2–5 V high) to select RF1, RF2, RF3, or all-off states - eliminating need for external decoding logic and reducing control line count from six to two while maintaining single +5 V supply operation.

Key Specifications

Pinout & Package

16-lead QSOP (Shrink Small Outline Package, JEDEC MO-137-AB), RoHS-compliant, MSL1, 100% matte tin plating, body material: low-stress injection-molded plastic with silica/silicon impregnation.

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 HMC245QS16E offers lowest system integration effort via its +5 V single supply and built-in TTL decoder - ideal for cost-sensitive, medium-frequency infrastructure designs where QSOP assembly is acceptable.

Availability

HMC245QS16E is available at Aetrix Electronics and suitable for basestation infrastructure, CATV/DBS headend systems, and wireless local loop CPE requiring stable component supply, long-lifecycle support, and consistent RF performance across production batches.

Supply support for HMC245QS16E 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 semiconductor company specializing in high-performance analog, mixed-signal, and RF technologies for precision signal processing applications.

The HMC245QS16E belongs to the Hittite Microwave (acquired by Analog Devices) GaAs MMIC switch product line, designed specifically for broadband RF path selection in communications infrastructure with emphasis on integration, reliability, and ease of use.

FAQ

What is the operating temperature range for the HMC245QS16E?

The HMC245QS16E operates over –40°C to +85°C ambient temperature, with guaranteed RF performance (insertion loss, isolation, return loss) validated across this full industrial range per datasheet specifications. Thermal resistance of the QSOP package is 150 °C/W on the insertion loss path, supporting reliable operation under continuous RF power conditions within these limits. The HMC245QS16E maintains stable switching characteristics without derating in this range.

Does the HMC245QS16E require external DC blocking capacitors?

Yes, the HMC245QS16E requires external DC blocking capacitors on all RF ports (RFC, RF1, RF2, RF3) when interfacing with circuits that must prevent DC voltage transfer - such as between biased amplifier stages and passive filters. Although the device is DC-coupled internally, system-level DC isolation is not provided; 100 pF 0402 capacitors are recommended per evaluation board design. The HMC245QS16E itself does not integrate blocking capacitors.

What logic levels are compatible with the A and B control inputs of the HMC245QS16E?

The A and B inputs of the HMC245QS16E accept standard TTL/CMOS logic: low state is 0–0.8 Vdc (≤0.2 µA leakage), high state is +2.0–+5.0 Vdc (≤35 µA leakage). They are fully compatible with +5 V microcontrollers, FPGAs, and logic families without level shifting. The HMC245QS16E does not support 1.8 V or 3.3 V logic directly unless pulled up to +5 V, as specified in the control voltage table.

How does the "All Off" state function in the HMC245QS16E?

When A = High and B = High, the HMC245QS16E places all RF paths (RF1, RF2, RF3) in high-isolation, non-reflective off-state while terminating each to 50 Ω. This provides >26 dB isolation across 0.3–3.5 GHz and eliminates signal leakage between ports - critical for RF mute, calibration, or safety interlock functions. The HMC245QS16E achieves this without external components or bias changes.

Is the HMC245QS16E pin-compatible with the HMC245AQS16E?

Yes, the HMC245QS16E and HMC245AQS16E share identical 16-lead QSOP pinout, electrical specifications, and functional behavior - the "A" suffix denotes a qualified automotive-grade variant with extended temperature screening and AEC-Q200 qualification, while the base HMC245QS16E meets industrial requirements. Both use the same footprint, truth table, and bias scheme; the HMC245QS16E is the standard industrial version referenced in all public datasheets and evaluation boards.