Analog Devices Inc. 119197-HMC657LP2

Overview

HMC657LP2E from Analog Devices (formerly Hittite Microwave) is a 15 dB wideband fixed SMT attenuator in a 6-lead 2×2 mm QFN package, operating from DC to 25 GHz with ±2.0 dB attenuation tolerance, 7 dB min return loss, and +25 dBm CW RF input power handling-used for impedance matching and signal level control in microwave radio front-ends.

For engineers reviewing the HMC657LP2E datasheet, HMC657LP2E pinout, HMC657LP2E application, or HMC657LP2E equivalent, key selection criteria include broadband flatness (DC–25 GHz), thermal stability (0.0006 dB/°C), RoHS-compliant matte Sn lead finish, MSL1 rating, and verified 50 Ω matched RF ports requiring DC blocking when biased signals are present.

Technical Context

This passive 50 Ω attenuator uses a monolithic thin-film resistive network integrated into a low-stress injection-molded plastic QFN package. Its symmetrical RF1/RF2 ports support bidirectional operation with DC coupling, and all ground leads plus the exposed paddle must be soldered to PCB RF ground per Hittite's land pattern guidelines.

Designed for high-frequency stability, it delivers <±0.5 dB variation across DC–20 GHz and maintains ≥7 dB return loss up to 25 GHz. The device exhibits Class 1B ESD sensitivity and operates from –40°C to +85°C, with absolute max DC voltage ratings of 4.4 V (terminated) and 4.6 V (open).

Key Specifications

Pinout & Package

6-lead 2×2 mm QFN package with exposed ground paddle; RoHS-compliant matte tin finish; low-stress injection-molded plastic body; copper alloy leadframe.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed attenuator applications.

Compared with QAT-15W+ and VAT-15W2+, the HMC657LP2E uniquely balances 25 GHz bandwidth, 2×2 mm footprint, and Class 1B ESD robustness - making it optimal for compact, wideband military and test instrumentation where both frequency reach and manufacturability matter.

Availability

HMC657LP2E is available at Aetrix Electronics and suitable for fiber optic transceivers, microwave radio links, and scientific instruments requiring stable component supply with guaranteed long-term traceability and RoHS compliance.

Supply support for HMC657LP2E 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-frequency RF portfolio into precision signal chain solutions.

The HMC657LP2E belongs to the Hittite wideband fixed attenuator family, engineered specifically for DC–25 GHz test, defense, and communications systems demanding flat response, thermal stability, and surface-mount reliability.

FAQ

What is the exact attenuation value and tolerance of the HMC657LP2E across temperature?

The HMC657LP2E provides a nominal 15 dB attenuation with a tolerance of ±2.0 dB over its full operating temperature range of –40°C to +85°C. This specification is validated per the official datasheet and applies to the entire DC–25 GHz band, ensuring predictable signal reduction in thermal-varying environments like outdoor base stations or aerospace avionics where HMC657LP2E is deployed.

Does the HMC657LP2E require DC blocking capacitors in the signal path?

Yes - the HMC657LP2E features DC-coupled RF1 and RF2 ports matched to 50 Ω, so external DC blocking capacitors are required if either the input or output signal carries non-zero DC potential. This prevents unintended bias shifts in connected amplifiers or mixers and preserves the specified return loss and attenuation accuracy of the HMC657LP2E.

What is the recommended PCB grounding practice for the HMC657LP2E?

All four ground pins (1, 3, 4, 6) and the exposed ground paddle must be soldered directly to the PCB's RF ground plane using multiple thermal vias. Hittite's application note specifies this as mandatory to achieve the published return loss and power handling. Inadequate paddle grounding degrades HMC657LP2E performance above 10 GHz and risks thermal overstress under +25 dBm operation.

Is the HMC657LP2E pin-compatible with other parts in the HMC656LP2E–HMC658LP2E family?

Yes - the HMC657LP2E shares identical 6-lead 2×2 mm QFN packaging, pinout, and land pattern with HMC656LP2E (10 dB) and HMC658LP2E (20 dB). This allows drop-in replacement within the same footprint for system-level attenuation tuning without PCB redesign, provided thermal and signal integrity margins remain sufficient for the selected HMC657LP2E value.

What is the maximum DC voltage the HMC657LP2E can tolerate at its RF ports?

The HMC657LP2E supports up to 4.4 V DC when the RF port is terminated (e.g., into 50 Ω), and up to 4.6 V DC when open-circuited. Exceeding these limits risks permanent damage. These ratings are lower than those of HMC656LP2E and HMC658LP2E due to internal resistor layout, and must be respected in bias-T or active antenna applications using HMC657LP2E.