Analog Devices Inc. HMC728LC3C

Overview

HMC728LC3C from Analog Devices (formerly Hittite Microwave) is a high-speed 2:1 CML selector IC used for ultra-fast data path routing in serial link infrastructure. It supports up to 14 Gbps data rate, 14 GHz select operation, single-ended inputs, differential CML outputs, and operates from a single -3.3 V supply in a 3×3 mm ceramic SMT package.

For engineers reviewing the HMC728LC3C datasheet, HMC728LC3C pinout, HMC728LC3C application, or HMC728LC3C equivalent, key selection criteria include its 125 ps propagation delay, 17/15 ps rise/fall times, 0.2 ps rms random jitter, -40°C to +85°C operating range, and compatibility with 50 Ω ground-terminated CML systems.

Technical Context

The HMC728LC3C implements a current-mode logic (CML) 2:1 multiplexer architecture with on-chip 50 Ω input termination to VCC and GND, enabling direct AC or DC coupling of single-ended inputs. Its differential CML outputs are source-terminated to 50 Ω and support direct connection to 50 Ω-terminated loads or downstream CML receivers.

It uses a negative supply (-3.3 V) referenced to ground, with all I/Os biased for CML logic levels. The device features low setup/hold time (6 ps), deterministic jitter of 2 ps p-p, and maintains signal integrity up to 14 GHz via optimized RF layout-evidenced by >10 dB input/output return loss below 14 GHz.

Key Specifications

Pinout & Package

Package: 16-lead ceramic LCC (3×3 mm, alumina body), RoHS-compliant, MSL3, gold-over-nickel plating, exposed paddle soldered to PCB ground.

Key Features

Applications

Equivalent & Alternatives

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

Compared with HMC853LC3C and ADN2880ACPZ-R7, the HMC728LC3C delivers the lowest propagation delay (125 ps) and jitter (0.2 ps rms) among 3×3 mm CML selectors rated for 14 Gbps, making it optimal for latency-critical ATE and test instrumentation where signal fidelity and timing precision are prioritized over extended data rate or added CDR functionality.

Availability

HMC728LC3C is available at Aetrix Electronics and suitable for high-speed serial multiplexing, RF automated test equipment, broadband test & measurement, redundant path switching, and built-in test applications requiring stable component supply and guaranteed long-term availability.

Supply support for HMC728LC3C 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, Inc. is a global leader in high-performance analog, mixed-signal, and RF ICs, formed in part through the acquisition of Hittite Microwave Corporation in 2014.

The HMC728LC3C belongs to Analog Devices' high-speed logic product line, engineered specifically for ultra-low-latency, low-jitter signal routing in test instrumentation, serial data infrastructure, and RF/microwave system interconnects.

FAQ

What is the maximum data rate supported by the HMC728LC3C?

The HMC728LC3C supports a maximum data rate of 14 Gbps under typical conditions (T_A = +25°C, V_ee = −3.3 V). This rating is validated with 2¹⁵−1 PRBS input patterns and confirmed across the full −40°C to +85°C operating temperature range. The HMC728LC3C also supports up to 14 GHz select port operation, making it suitable for high-speed serial multiplexing in applications such as 100G Ethernet KR4 and InfiniBand EDR.

Does the HMC728LC3C require external termination resistors?

No, the HMC728LC3C does not require external termination resistors for its single-ended CML inputs (AP, BP) or differential CML outputs (DP, DN). Inputs are internally terminated to 50 Ω between VCC and GND; outputs are source-terminated to 50 Ω. External termination is only needed if driving non-50 Ω loads or implementing custom biasing-otherwise, the HMC728LC3C operates optimally with direct connection to 50 Ω-terminated systems.

What is the supply voltage requirement for the HMC728LC3C?

The HMC728LC3C operates from a single negative supply of −3.3 V, with an allowable range of −3.6 V to −3.0 V. It is not compatible with positive supply rails or dual-supply configurations. The device draws approximately 76 mA from V_ee, resulting in ~250 mW typical power dissipation. Proper local decoupling-using a 4.7 µF tantalum capacitor and 100 pF 0402 ceramic-is required at the V_ee pins (13 and 16) for stable high-speed operation.

Can the HMC728LC3C be used with AC-coupled inputs and outputs?

Yes, the HMC728LC3C supports both AC- and DC-coupled interfaces. Its CML inputs (AP, BP, SP, SN) and outputs (DP, DN) are designed for either coupling method. When AC-coupling, ensure DC blocking capacitors are placed close to the device and that common-mode voltage levels remain within specification (e.g., input V_cm = −0.300 V typical). The HMC728LC3C's internal biasing eliminates the need for external DC restoration circuits in most standard CML interface configurations.

What is the thermal management requirement for the HMC728LC3C?

The HMC728LC3C has a thermal resistance (R_{th j-p}) of 59 °C/W from junction to package paddle. To maintain junction temperature ≤125°C at maximum ambient (85°C), the PCB must provide low-thermal-resistance conduction from the exposed paddle (Pin 14) to a solid ground plane using multiple thermal vias. The absolute maximum continuous power dissipation is 0.68 W at 85°C, derating by 17 mW/°C above that temperature. The HMC728LC3C's 250 mW typical dissipation allows safe operation without forced air in most test and measurement PCB layouts.