Analog Devices Inc. HMC290E

Overview

HMC290E from Analog Devices (formerly Hittite Microwave) is a GaAs MMIC 2-bit digital attenuator in SOT-26 package, delivering 2 dB LSB and 4 dB MSB attenuation steps across 0.7–4.0 GHz with ≤0.8 dB typical insertion loss at 4 GHz, ±0.2 dB typical bit error, and +52 dBm IIP3 at 5 V supply - deployed in RF front-ends of cellular base stations and PCS handsets.

For engineers reviewing the HMC290E datasheet, HMC290E pinout, HMC290E application, or HMC290E equivalent, key selection criteria include broadband attenuation accuracy over temperature (−40°C to +85°C), low control current (<50 µA per bit), single positive 3–5 V bias requirement, and RoHS-compliant matte tin lead finish compatible with 260°C peak reflow.

Technical Context

The HMC290E implements a monolithic GaAs-based switched-resistor architecture with two independent CMOS-compatible control inputs (V1, V2), each toggling between 0 V and Vdd to select attenuation states (0, 2, 4, or 6 dB). Bias is applied via a single external 5 kΩ resistor to Pin 3 (Vdd) or Pin 1 (RF1), eliminating need for separate gate bias networks.

It operates without DC blocking on control lines but mandates external 100–300 pF AC-coupling capacitors on RF1 and RF2 ports. Return loss exceeds 15 dB across full band, and switching times are tightly specified at tRISE/tFALL = 400 ns and tON/tOFF = 420 ns, enabling fast AGC loop response in dynamic RF systems.

Key Specifications

Pinout & Package

SOT-26 plastic package with RoHS-compliant 100% matte Sn lead finish, MSL1 rating, and 260°C peak reflow tolerance. All ground leads (Pins 2, 4, 5, 6) must be soldered directly to PCB RF ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with HMC290E, HMC624LP4E offers higher resolution but larger size and lower linearity, while QM11028 matches package and frequency but adds supply complexity - HMC290E remains optimal for single-supply, space-constrained, high-linearity 2-bit attenuation.

Availability

HMC290E is available at Aetrix Electronics and suitable for cellular infrastructure, PCS handset RF front-ends, and WLL base station designs requiring stable component supply, long-term obsolescence mitigation, and RoHS-compliant manufacturing readiness.

Supply support for HMC290E 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, specializing in GaAs and SiGe MMICs for wireless infrastructure and defense applications.

The HMC290E belongs to Hittite's legacy digital attenuator family designed specifically for broadband, low-power, surface-mount RF gain control in commercial wireless equipment - emphasizing small size, high accuracy, and single-supply simplicity.

FAQ

What is the maximum RF input power the HMC290E can handle without damage?

The HMC290E has an absolute maximum RF input power rating of +28 dBm across 0.7–4.0 GHz. Under normal operation, its 0.1 dB compression point is +27 dBm at 5 V supply and +24 dBm at 3 V. These values define safe linear operating limits - exceeding them risks permanent GaAs FET degradation. Always verify thermal derating in high-duty-cycle applications.

Does the HMC290E require external DC blocking capacitors on its RF ports?

Yes, the HMC290E requires external DC blocking capacitors on both RF1 (Pin 1) and RF2 (Pin 3 or alternate RF path) ports. The datasheet specifies 100–300 pF chip capacitors sized to pass the lowest operating frequency with minimal loss - for example, 220 pF for 700 MHz operation. Omitting them risks bias disruption and potential device latch-up.

Can the HMC290E operate from a 3.3 V supply, and how does that affect performance?

Yes, the HMC290E is fully specified for 3–5 V Vdd operation. At 3.3 V, IIP3 drops from +52 dBm to +50 dBm, P1dB decreases from +27 dBm to +24 dBm, and attenuation accuracy degrades slightly (±0.3 dB max for 6 dB state). All control thresholds remain valid, and quiescent current stays below 50 µA per bit.

Is the HMC290E pin-compatible with the non-RoHS HMC290 variant?

Yes, the HMC290E is a direct RoHS-compliant replacement for the HMC290, sharing identical SOT-26 pinout, electrical specifications, and mechanical outline. The only differences are matte Sn lead finish (vs. Sn/Pb), higher 260°C reflow rating (vs. 235°C), and MSL1 packaging - no PCB or schematic changes are needed for migration.

What is the recommended PCB layout practice for grounding the HMC290E?

Per the HMC290E datasheet, all four ground pins (Pins 2, 4, 5, 6) must be soldered directly to a solid RF ground plane using multiple thermal vias (≥4 per pin). The evaluation board uses Rogers 4350 substrate with 50 Ω controlled-impedance traces. Avoid stubs or narrow traces on RF paths - keep RF1/RF2 routing symmetrical and under 3 mm length for best return loss.