Analog Devices Inc. HMC986A

Overview

HMC986A from Analog Devices is a reflective GaAs MMIC single-pole double-throw (SPDT) RF switch operating from 0.1 GHz to 50 GHz, delivering 2.3 dB insertion loss and 30 dB isolation at 50 GHz with −5 V to −3 V negative logic control. It serves as a broadband signal routing element in test instrumentation and military radar front-ends where high-frequency switching integrity and power handling are critical.

For engineers reviewing the HMC986A datasheet, HMC986A pinout, HMC986A application, or HMC986A equivalent, key selection criteria include its 50 Ω reflective architecture, 28 dBm P1dB linearity, 13-pad bare-die package with ground-signal-ground RF interface, and compatibility with eutectic die attach on alumina substrates.

Technical Context

The HMC986A implements a monolithic GaAs-based reflective SPDT topology with dc-coupled RF pads (RFC, RF1, RF2) and dual negative-voltage control inputs (V1/V2). Its operation relies on complementary bias states to steer RF energy between RFC and either RF1 or RF2 while maintaining 50 Ω termination on the unselected path.

Thermal management requires direct eutectic or conductive epoxy attachment of the die bottom to ground, with θJC = 260°C/W. RF performance is measured using 3.0 mil × 0.5 mil ribbon bonds to 50 Ω microstrip lines on 5 mil alumina substrates - bond length minimization is essential for preserving broadband response up to 50 GHz.

Key Specifications

Pinout & Package

13-pad bare die (C-13-1), 0.98 mm × 0.75 mm × 0.1 mm, with backside metallization requiring eutectic or conductive epoxy attachment to PCB ground plane. RF pads (RFC, RF1, RF2) and control pads (V1, V2) are surface-mounted via ribbon bonding; all GND pads connect to die backside ground.

Key Features

Applications

Equivalent & Alternatives

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

Compared with HMC986A, HMC1082 extends low-frequency coverage but sacrifices insertion loss and power handling, while HMC646 reduces size and cost at the expense of upper-band performance - HMC986A remains optimal for balanced 0.1–50 GHz, high-linearity, high-isolation requirements.

Availability

HMC986A is available at Aetrix Electronics and suitable for test instrumentation, military radar front-ends, and Ka-band VSAT systems requiring stable component supply across extended temperature ranges and high-frequency performance consistency.

Supply support for HMC986A 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 is a global leader in high-performance analog, mixed-signal, and RF ICs, serving precision instrumentation, communications, and defense markets with industry-leading process technologies.

The HMC986A belongs to Analog Devices' Hittite Microwave MMIC product line, engineered specifically for broadband RF signal routing in demanding military, aerospace, and test equipment applications where GaAs performance exceeds silicon alternatives.

FAQ

What is the recommended RF bond configuration for the HMC986A?

The HMC986A requires 3.0 mil × 0.5 mil gold ribbon bonds for RF pads (RFC, RF1, RF2) to minimize inductance and preserve broadband performance up to 50 GHz. DC control signals (V1/V2) should use 1 mil diameter gold wire bonds. All bonds must be as short as possible, with typical die-to-substrate spacing of 0.076 mm (3 mil) to reduce parasitic effects that degrade isolation and return loss.

Does the HMC986A require dc blocking capacitors on its RF ports?

No, the HMC986A does not require dc blocking capacitors on RFC, RF1, or RF2 because all three RF pads are dc-coupled to 0 V and ac-matched to 50 Ω. This design eliminates insertion loss and phase discontinuity introduced by capacitors, enabling true dc-to-50 GHz operation - provided the connected RF line potential is held at 0 V dc.

How is thermal management implemented for the HMC986A?

The HMC986A die bottom must be attached directly to the PCB ground plane using gold-tin (AuSn) eutectic preforms or electrically conductive epoxy to establish low-thermal-resistance conduction. With θJC = 260°C/W, effective heat dissipation depends on PCB copper area, ground plane thickness, and substrate material - inadequate thermal design risks exceeding the 150°C maximum junction temperature during 27 dBm continuous operation.

What control voltage levels are valid for reliable operation of the HMC986A?

The HMC986A requires two negative logic control voltages: V1 and V2 must be driven to −5 V to −3 V for logic low (active) and 0 V for logic high (inactive). Applying −5.5 V or +0.5 V violates absolute maximum ratings and may damage ESD protection structures. Current draw is ≤10 µA per control input when asserted, enabling direct drive from standard GaAs logic drivers without buffering.

Can the HMC986A be used in bidirectional RF signal paths?

Yes, the HMC986A is fully bidirectional: RF signals may be applied to RFC with outputs taken from RF1/RF2, or applied to RF1/RF2 with output taken from RFC. This flexibility supports both transmit-path switching (RFC → RF1/RF2) and receive-path switching (RF1/RF2 → RFC) in TDD systems, with identical insertion loss, isolation, and linearity specifications in either direction.