Analog Devices Inc. HMC528LC4

Overview

HMC528LC4 from Analog Devices (formerly Hittite Microwave) is a GaAs MMIC I/Q mixer operating as an image-reject mixer or single-sideband upconverter in RF/LO bands of 11–16 GHz and IF bandwidth DC–3.5 GHz, delivering 10.5 dB typical conversion loss, 35 dB image rejection, and +26 dBm input IP3 - deployed in point-to-point radios and military communications systems.

For engineers reviewing the HMC528LC4 datasheet, HMC528LC4 pinout, HMC528LC4 application, or HMC528LC4 equivalent, this device requires attention to its 24-lead 4×4 mm SMT package grounding scheme, LO drive sensitivity (+19 dBm nominal), quadrature IF port biasing constraints (≤3 mA DC current), and absence of internal IF hybrid - all critical for RF layout integrity and sideband suppression performance.

Technical Context

The HMC528LC4 integrates two double-balanced GaAs MESFET mixer cells with an on-die 90° hybrid to enable image-reject downconversion or USB upconversion without external phase-shifting networks. Its RF and LO ports are AC-coupled and 50 Ω matched across 11–16 GHz, while IF1 and IF2 are DC-coupled differential outputs requiring external hybrid for true I/Q summation.

Operation relies on precise amplitude and phase balance (0.4 dB / 5° typ.) between quadrature paths, supported by high LO-to-RF isolation (45 dB) and low spurious generation (e.g., 3rd LO harmonic >61 dBc). It operates over –40°C to +85°C with absolute max LO drive of +27 dBm and channel temperature limit of 150°C.

Key Specifications

Pinout & Package

Package: 24-lead leadless SMT, 4×4 mm alumina body, gold-over-nickel plating, MSL3, thermal resistance 145 °C/W (junction-to-die bottom). Ground paddle and all GND pins must be soldered to PCB RF ground plane with multiple vias.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I/Q mixer applications.

Compared with HMC8192LP5E and QM11028, the HMC528LC4 offers optimal balance of integration (on-die hybrid), compact 4×4 mm footprint, and proven 35 dB image rejection at +19 dBm LO - making it the preferred choice for production-grade microwave radios where size, manufacturability, and calibrated sideband suppression are prioritized.

Availability

HMC528LC4 is available at Aetrix Electronics and suitable for point-to-point radios, VSAT terminals, and military communications systems requiring stable component supply, RoHS-compliant SMT placement, and guaranteed long-term availability in microwave frequency bands.

Supply support for HMC528LC4 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 portfolio, specializing in GaAs and GaN MMICs for defense, aerospace, and wireless infrastructure.

The HMC528LC4 belongs to Hittite's legacy I/Q mixer product line, designed specifically for compact, high-performance microwave upconversion and image-reject downconversion in commercial and military radios.

FAQ

What is the recommended LO drive level for optimal performance of the HMC528LC4?

The HMC528LC4 achieves best image rejection and conversion gain flatness at +19 dBm LO drive. Deviation to +17 dBm or +21 dBm degrades sideband rejection by up to 6 dB and increases amplitude/phase imbalance. The device supports LO drive up to +27 dBm absolute maximum, but sustained operation above +21 dBm risks accelerated degradation without thermal derating.

Can the HMC528LC4 operate as a downconverter, and what external components are required?

Yes, the HMC528LC4 functions as an image-reject downconverter when RF is applied to Pin 4 and LO to Pin 15, producing I/Q outputs at Pins 9 and 11. An external IF hybrid is required to sum I/Q signals into a single IF output; the device itself does not include this hybrid. DC blocking capacitors are needed on IF outputs if operation below ~10 MHz is not required.

What are the grounding requirements for the HMC528LC4 to ensure RF performance?

All GND pins (3, 5, 12, 14, 16) and the exposed ground paddle must be soldered to a solid RF ground plane using ≥8 thermal vias within 2 mm of the paddle edge. N/C pins may be grounded but are not required. Inadequate grounding causes degraded LO-to-RF isolation (<40 dB) and increased conversion loss variation across frequency.

Does the HMC528LC4 support DC-coupled IF operation, and what are the current limits?

Yes, Pins 9 (IF1) and 11 (IF2) are DC-coupled, enabling zero-IF architectures. However, each IF pin must not source or sink more than ±3 mA DC current; exceeding this causes non-function or permanent damage. For AC-coupled operation, a series capacitor sized for the lowest IF frequency (e.g., 100 pF for 10 MHz cutoff) is recommended.

Is the HMC528LC4 pin-compatible with other Hittite I/Q mixers such as the HMC527LC4?

No, the HMC528LC4 is not pin-compatible with HMC527LC4. While both are 24-lead 4×4 mm packages, their pin functions differ: HMC527LC4 uses Pin 15 for IF1 and Pin 9 for LO, whereas HMC528LC4 assigns Pin 15 to LO and Pin 9 to IF1. PCB layout and schematic must be redesigned for HMC528LC4 replacement.