Analog Devices Inc. HMC346LP3ETR

Overview

HMC346LP3ETR from Analog Devices (formerly Hittite Microwave) is a GaAs MMIC voltage-variable attenuator (VVA) operating from DC to 14 GHz, providing 30 dB analog attenuation range with low phase shift vs. attenuation, 2.2 dB typical insertion loss at 10 GHz, and single-voltage control (0 to –3 V). It serves as an RF signal-level controller in microwave infrastructure where precise amplitude adjustment via DC bias is required.

For engineers reviewing the HMC346LP3ETR datasheet, HMC346LP3ETR pinout, HMC346LP3ETR application, or HMC346LP3ETR equivalent, key selection criteria include its 3×3×1 mm leadless SMT package, absorptive architecture, 50 Ω RF ports, on-chip reference attenuator for op-amp-based control, and compatibility with high-frequency test instrumentation and broadband telecom systems.

Technical Context

The HMC346LP3ETR implements an absorptive GaAs MMIC topology with integrated reference attenuator circuitry, enabling stable impedance matching across its full 30 dB attenuation range. Its control interface supports master/slave configuration via dual control inputs (V1/V2 and I), allowing synchronized attenuation in multi-channel systems.

It operates over –40 °C to +85 °C with ESD rating Class 1A (HBM), requires PCB RF grounding of all ground pins and the exposed paddle, and delivers <2.8 dB insertion loss up to 14 GHz while maintaining >5 dB return loss across DC–14 GHz.

Key Specifications

Pinout & Package

Package: 16-pin leadless plastic QFN (3 × 3 × 1 mm), with exposed metal paddle requiring soldering to PCB RF ground.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage-variable attenuator applications.

Compared with HMC121C8 and HMC650LP3E, the HMC346LP3ETR offers optimal balance of bandwidth (DC–14 GHz), compact size, and proven stability in deployed microwave infrastructure-making it ideal for cost-sensitive, field-proven 6–12 GHz systems where full Ka-band extension is unnecessary.

Availability

HMC346LP3ETR is available at Aetrix Electronics and suitable for basestation infrastructure, fiber optics & broadband telecom, and microwave radio & VSAT applications requiring stable component supply, long-lifecycle support, and consistent RF performance across production batches.

Supply support for HMC346LP3ETR 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 maintains its high-frequency RF product portfolio, including GaAs MMICs for defense, telecom, and instrumentation markets.

The HMC346LP3ETR belongs to the Hittite voltage-variable attenuator family, designed specifically for analog-controlled RF amplitude management in microwave infrastructure where low phase distortion and wide bandwidth are essential.

FAQ

What is the maximum RF input power rating for the HMC346LP3ETR?

The HMC346LP3ETR has an absolute maximum RF input power rating of +18 dBm. Operation above this level risks permanent damage. For reliable linear operation, the datasheet specifies +8 dBm input power for 0.25 dB compression at minimum attenuation and –4 dBm when attenuation exceeds 2 dB-guiding safe operating envelope selection in receiver and transmitter chains.

Does the HMC346LP3ETR require external DC blocking capacitors on its RF ports?

Yes, the HMC346LP3ETR RF1 and RF2 pins are DC-coupled and matched to 50 Ω. If the connected RF line carries non-zero DC potential, external DC blocking capacitors must be used to prevent bias disruption or device damage. The evaluation PCB design confirms this requirement with series capacitors on both RF paths.

How is the exposed paddle on the HMC346LP3ETR package used in PCB layout?

The exposed metal paddle on the HMC346LP3ETR must be soldered directly to the PCB's RF ground plane. Per the datasheet, all ground pins (1, 3, 7, 10, 12) and the paddle form a unified RF ground structure-failure to connect the paddle degrades return loss, increases insertion loss, and compromises thermal dissipation and ESD robustness.

Can the HMC346LP3ETR be used in a single-control configuration without the slave pin?

Yes, the HMC346LP3ETR supports single-control operation using only V1 and V2 (pins 5 and 8); the I pin (pin 6) is optional for slave-mode synchronization. When unused, the I pin should be grounded. The internal control architecture allows full 30 dB attenuation range with just the master inputs and an external op-amp driver circuit.

What is the ESD sensitivity classification for the HMC346LP3ETR?

The HMC346LP3ETR is classified as Class 1A per HBM (Human Body Model), meaning it withstands up to 250 V ESD stress. This mandates strict handling precautions-including grounded workstations, ionized air, and ESD-safe packaging-especially during manual assembly or probe testing, given its GaAs MMIC process and fine-pitch QFN construction.