Analog Devices Inc. HMC674LP3ETR

Overview

HMC674LP3ETR from Analog Devices is a 9.3 GHz SiGe latched comparator with RSPECL outputs, 85 ps propagation delay, 60 ps minimum input pulse width, and resistor-programmable hysteresis-designed for 10 Gbps clock/data restoration and high-speed ATE trigger circuits.

For engineers reviewing the HMC674LP3ETR datasheet, HMC674LP3ETR pinout, HMC674LP3ETR application, or HMC674LP3ETR equivalent, key selection criteria include latch enable timing (tS = 45 ps, tH = −42 ps), RSPECL output drive into 50 Ω (VOL = 0.71 V, VOH = 1.09 V), and −40°C to +85°C operation in a 3 mm × 3 mm LFCSP package.

Technical Context

The HMC674LP3ETR integrates three functional blocks: a high-bandwidth SiGe input amplifier, a level-sensitive latch with differential LE/LE control, and RSPECL output buffers capable of driving 400 mV into 50 Ω terminated to VTT = VCCO − 2.0 V. It supports both transparent (track) and hold (latch) modes via LE/LE logic state.

Its 9.3 GHz equivalent input bandwidth, 0.2 ps rms random jitter, and 10 ps overdrive/slew rate dispersion enable precise edge detection in broadband digital receiver systems and pulse spectroscopy-where deterministic timing accuracy and minimal pulse distortion are critical.

Key Specifications

Pinout & Package

Package: 16-lead lead frame chip scale package (LFCSP), 3 mm × 3 mm body, 0.90 mm height, exposed pad requiring connection to VEE per JEDEC MO-220-VEED-4.

Key Features

Applications

Equivalent & Alternatives

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

Compared with HMC674LC3C and ADCMP572BCPZ-R7, the HMC674LP3ETR uniquely combines 9.3 GHz bandwidth, latch mode, RSPECL outputs, and MSL1-compatible LFCSP packaging-making it the only option for production-grade, reflowable 10 Gbps trigger and CDR designs requiring <100 ps timing fidelity.

Availability

HMC674LP3ETR is available at Aetrix Electronics and suitable for automatic test equipment (ATE), high-speed digital receiver systems, and pulse spectroscopy instrumentation requiring stable component supply, RoHS compliance, and MSL1 handling capability.

Supply support for HMC674LP3ETR 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 industrial markets since 1965.

The HMC674LP3ETR belongs to Analog Devices' Hittite Microwave legacy ultrafast comparator product line, engineered specifically for sub-100 ps timing-critical applications in ATE, broadband communications, and scientific instrumentation.

FAQ

What is the maximum operating frequency supported by the HMC674LP3ETR?

The HMC674LP3ETR supports 10 Gbps operation with a typical equivalent input bandwidth of 9.3 GHz. Its 60 ps minimum input pulse width and 85 ps propagation delay enable reliable signal discrimination at bit rates up to 10 Gbps in clock and data recovery applications. The device maintains this performance across its full −40°C to +85°C operating temperature range, as verified in the Rev. K datasheet.

Does the HMC674LP3ETR require external termination resistors on its inputs?

Yes, the HMC674LP3ETR requires 50 Ω series termination on both INP and INN inputs, with VTP and VTN connected to the appropriate return (ground or VTT). Figure 5 of the datasheet shows this configuration explicitly. Failure to terminate properly degrades bandwidth and increases reflection-induced jitter, directly impacting the 0.2 ps rms jitter specification of the HMC674LP3ETR.

How is latch mode enabled on the HMC674LP3ETR?

Latch mode is enabled by driving the LE pin high and LE pin low simultaneously-i.e., asserting the differential latch enable pair. In latch mode, the HMC674LP3ETR holds the output state corresponding to the input comparison result just before the LE/LE transition. Track mode occurs when LE is low and LE is high. Both modes are fully specified in Tables 2 and 6 of the HMC674LP3ETR datasheet.

Can the HMC674LP3ETR operate with different supply voltages for VCCI and VCCO?

Yes, the HMC674LP3ETR supports independent supplies: VCCI = 3.3 V ±3% for the input stage and VCCO = 1.8 V to 3.3 V for the RSPECL output stage. This separation minimizes noise coupling between analog and digital sections. The datasheet specifies VCCO = 2.0 V for optimal RSPECL output swing (440–980 mV p-p), confirming that HMC674LP3ETR operation is validated across this range.

What is the recommended PCB layout practice for the exposed thermal pad of the HMC674LP3ETR?

The exposed pad of the HMC674LP3ETR must be soldered directly to the VEE plane using ≥6 thermal vias (0.3 mm diameter, spaced ≤1 mm apart) to achieve the specified θJC of 23°C/W. Per Figures 17–18 and the "Pin Configurations" section, failure to connect the EPAD to VEE causes thermal runaway above 100 mW and violates the absolute maximum junction temperature rating of 125°C for the HMC674LP3ETR.