Analog Devices Inc. HMC854LC5

Overview

HMC854LC5 from Analog Devices (formerly Hittite Microwave) is a high-speed 4:1 multiplexer IC designed for 28 Gbps NRZ serial data transmission in optical and high-speed digital systems. It features CML-compatible differential I/O, on-chip quarter-rate clock generation, programmable output voltage swing (700–1250 mV), and operates from a single -3.3 V supply in a 32-lead ceramic SMT package.

For engineers reviewing the HMC854LC5 datasheet, HMC854LC5 pinout, HMC854LC5 application, or HMC854LC5 equivalent, key selection considerations include its 28 Gbps data rate, half-rate clock input architecture, VR-controlled output amplitude tuning, low 16 ps rise/fall times, and compatibility with SONET OC-192, FPGA interconnect, and broadband test instrumentation.

Technical Context

The HMC854LC5 implements a current-mode logic (CML) 4:1 mux that latches four differential inputs on the rising edge of a half-rate clock (up to 14 GHz), then serializes using both edges to achieve 28 Gbps NRZ operation. Its internal quarter-rate reference clock (C/4) is generated and output for system synchronization.

All CML inputs are on-chip 50 Ω terminated to Vee or GND; outputs are source-terminated to 50 Ω and support AC/DC coupling. The VR pin enables real-time adjustment of differential output swing across temperature and board loss - critical for maintaining signal integrity in high-loss PCB traces or connector interfaces.

Key Specifications

Pinout & Package

Package: 32-lead ceramic LCC (5 × 5 mm, 0.5 mm pitch), alumina body, gold-over-nickel plating, MSL3, exposed paddle soldered to Vee.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed multiplexer applications.

Compared with HMC987LP5E and LMK04906, the HMC854LC5 uniquely delivers 28 Gbps NRZ operation with on-chip C/4 clock generation and analog VR-based output swing tuning - making it optimal for space-constrained, high-fidelity serial data aggregation where timing precision and channel loss compensation are critical.

Availability

HMC854LC5 is available at Aetrix Electronics and suitable for SONET OC-192 infrastructure, FPGA-based high-speed interconnects, and broadband test instrumentation requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for HMC854LC5 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, microwave, and millimeter-wave IC portfolio into precision signal processing solutions.

The HMC854LC5 belongs to Analog Devices' high-speed data converter and interface product line, engineered specifically for 25–28 Gbps serial data infrastructure in telecom, test equipment, and advanced computing.

FAQ

What is the maximum supported data rate for the HMC854LC5?

The HMC854LC5 supports a maximum data rate of 28 Gbps in NRZ format, verified under PRBS2^15 test conditions at 25 °C with -3.3 V supply. It also demonstrates usable eye opening at 30 Gbps in evaluation setups, though 28 Gbps is the guaranteed specification. This makes the HMC854LC5 suitable for OC-192, 100G Ethernet CAUI-4, and high-end test instrumentation applications.

How does the VR pin affect the HMC854LC5's output performance?

The VR pin on the HMC854LC5 directly controls differential output voltage swing from 700 mV to 1250 mV, as shown in the "Output Differential vs. VR" plot in the datasheet. Applying a voltage between -0.4 V and +0.4 V adjusts output amplitude to compensate for PCB trace loss or receiver sensitivity mismatch. At VR = 0 V, the typical swing is 1000 mVpp - a key setting for standard CML interfacing in the HMC854LC5.

Is the HMC854LC5 compatible with AC-coupled CML interfaces?

Yes, the HMC854LC5 supports both AC- and DC-coupled CML interfaces. All inputs are internally terminated to 50 Ω and accept either coupling method; outputs are source-terminated to 50 Ω and can drive AC-coupled 50 Ω loads directly. For AC coupling, external DC blocking capacitors must be placed close to the device, and proper common-mode biasing must be maintained - confirmed in HMC854LC5 application schematics.

What is the recommended power supply configuration for the HMC854LC5?

The HMC854LC5 requires a single -3.3 V supply (range: -3.45 V to -3.3 V typical) delivered to all Vee pins (27, 30) and the exposed paddle. Decoupling must include bulk capacitance (e.g., 4.7 µF tantalum) and high-frequency bypassing (e.g., 100 pF 0402) near each Vee pin. The exposed paddle must be soldered to the -3.3 V plane with ≥6 thermal vias - per HMC854LC5 evaluation board guidelines and absolute maximum ratings.

Does the HMC854LC5 provide a clock output, and what is its function?

Yes, the HMC854LC5 provides a differential quarter-rate clock output (C/4±) on pins 23 and 24. This output is derived from the internal half-rate clock (C/2±) and serves as a low-jitter timing reference for downstream devices such as clock-and-data-recovery (CDR) ICs or sampling oscilloscopes. It eliminates the need for an external clock divider and maintains phase coherence with the serialized data stream in the HMC854LC5.