Analog Devices Inc. HMC675LC3C

Overview

HMC675LC3C from Analog Devices (formerly Hittite Microwave) is a SiGe monolithic latched comparator with 10 GHz equivalent input bandwidth, 100 ps propagation delay, and RSCML output stage delivering 400 mV differential swing into 50 Ω. It operates in latch or track mode and supports 10 Gbps data acquisition in high-speed ATE and clock/data restoration systems.

For engineers reviewing the HMC675LC3C datasheet, HMC675LC3C pinout, HMC675LC3C application, or HMC675LC3C equivalent, key selection criteria include deterministic jitter (2 ps pp), random jitter (0.2 ps rms), programmable hysteresis, latch enable timing (tS = 45 ps, tH = –42 ps), and compatibility with RF-optimized PCB layouts requiring exposed paddle soldering to Vee.

Technical Context

The HMC675LC3C integrates three functional blocks: a high-gain input amplifier, a level-sensitive single latch, and an RSCML output buffer. Its latch control uses complementary LE/LE_bar inputs with 8 kΩ input impedance and supports both transparent (track) and hold (latch) modes via logic-level enable signaling.

Input stage features 50 Ω differential impedance, ±1.75 V differential input range, and ±5 mV offset voltage with 15 µV/°C drift. Output stage delivers RS-CML-compatible levels (V_OH = –10 mV, V_OL = –400 mV typ.) with 27 ps rise / 18 ps fall times, optimized for direct 50 Ω termination to ground.

Key Specifications

Pinout & Package

16-lead 3×3 mm ceramic SMT package (alumina body, gold-over-nickel plating, MSL3); exposed paddle must be soldered to Vee for thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar latched comparator applications.

Compared with ADCLK948BCPZ and HMC874LC3C, the HMC675LC3C uniquely combines RSCML output compatibility, resistor-programmable hysteresis, and dual-mode (latch/track) operation in a thermally optimized 3×3 mm package-making it the sole choice for compact, low-jitter, reconfigurable high-speed sampling front-ends.

Availability

HMC675LC3C is available at Aetrix Electronics and suitable for ATE signal acquisition, digital receiver clock recovery, pulse spectroscopy triggering, and high-speed instrumentation front-end applications requiring stable component supply and guaranteed long-term sourcing.

Supply support for HMC675LC3C 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 semiconductor leader specializing in high-performance analog, mixed-signal, and RF technologies for precision and high-speed applications.

The HMC675LC3C belongs to Analog Devices' high-speed comparator product line, designed specifically for 10 Gbps+ data acquisition, clock/data restoration, and RF instrumentation where sub-100 ps timing accuracy and ultra-low jitter are mission-critical.

FAQ

What is the recommended power supply configuration for HMC675LC3C?

The HMC675LC3C requires three independent supplies: Vcci = +3.3 V for the input stage, Vcco = 0 V (ground) for the output stage, and Vee = –3 V for the negative rail. The exposed paddle must be soldered to Vee. Decoupling capacitors (100 pF and 4.7 µF) are required at each supply pin per the evaluation board layout to maintain 0.2 ps rms random jitter performance.

How does the HMC675LC3C implement latch versus track mode operation?

The HMC675LC3C switches between latch (hold) and track (transparent) modes using complementary LE and LE_bar inputs. Latch mode activates when LE–LE_bar is high; track mode activates when LE–LE_bar is low or both inputs float. This dual-mode capability is built into the silicon and requires no external configuration registers or firmware-enabling real-time reconfiguration in hardware-defined signal paths.

Can the HMC675LC3C drive standard 50 Ω CML receivers directly?

Yes, the HMC675LC3C's RSCML output stage delivers 400 mV differential swing into a 50 Ω load terminated to ground, matching standard CML receiver input requirements. No AC coupling, level shifting, or termination adjustments are needed-simplifying interconnect design and preserving signal integrity up to 10 Gbps.

What is the purpose of the HYS pin on the HMC675LC3C?

The HYS pin on the HMC675LC3C enables resistor-programmable hysteresis: leaving it open yields zero hysteresis; connecting it to Vee via a resistor sets hysteresis voltage (e.g., 10 kΩ → ±1 mV). This feature improves noise immunity in low-SNR environments without altering the comparator's core timing performance or requiring additional ICs.

Is the HMC675LC3C pin-compatible with other Hittite/Analog Devices comparators in the same package?

No, the HMC675LC3C is not pin-compatible with other comparators in the 3×3 mm LCC package (e.g., HMC874LC3C or HMC674LC3C). Pin functions differ significantly-especially LE/LE_bar placement, Vcco assignment, and HYS functionality-requiring unique PCB layout and schematic integration for each device.