Analog Devices Inc. AD96687BR

Overview

AD96687BR from Analog Devices is a dual ultrafast ECL-compatible voltage comparator with 2.5 ns propagation delay, 50 ps delay dispersion, and latch-enable functionality for track/hold operation. It operates from +5 V and –5.2 V supplies, supports –2.5 V to +5 V common-mode input range, and drives 50 Ω ECL loads terminated to –2.0 V-used in high-speed sampling circuits and window comparators.

For engineers reviewing the AD96687BR datasheet, AD96687BR pinout, AD96687BR application, or AD96687BR equivalent, this page delivers verified electrical specs, SOIC-16 pin mapping, real-world timing-critical use cases, and two validated alternative comparators with documented functional trade-offs.

Technical Context

The AD96687BR implements two independent high-speed differential comparators with complementary open-emitter outputs, each featuring a level-sensitive latch enable (active-low) for synchronous sampling control. Its input stage maintains consistent 2.5 ns propagation delay across 100 mV–1 V overdrive, minimizing timing jitter in threshold detection.

It requires dual-rail ECL-compatible supplies (+5 V / –5.2 V), uses separate analog and digital ground pins (GROUND 1 and GROUND 2), and mandates external 50–200 Ω pull-down resistors to –2.0 V on Q and Q outputs. Latch enable logic polarity differs between channels per functional diagram: one LE active low, the other active high.

Key Specifications

Pinout & Package

AD96687BR is housed in a 16-pin SOIC package (R-16A), with exposed pad not electrically connected. Pin layout follows standard SOIC-16 footprint (5.08 mm pitch, 10.00 mm × 4.00 mm body), compatible with automated assembly and reflow.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD96687BR, MAX9602ASA+ offers faster delay but lacks dual-channel integration and ECL output drive, while TLV3501CD eliminates negative supply requirements but sacrifices both speed and ECL interoperability-making AD96687BR uniquely suited for legacy high-speed ECL sampling systems needing dual synchronized comparators.

Availability

AD96687BR is available at Aetrix Electronics and suitable for high-speed sampling circuits, window comparators, peak detector triggers, and high-speed line receivers requiring stable component supply across industrial temperature range (–25°C to +85°C).

Supply support for AD96687BR 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 digital signal processing semiconductors, founded in 1965 and headquartered in Wilmington, MA.

The AD96685/AD96687 family was engineered specifically for timing-critical ECL-based instrumentation-delivering ultra-low delay dispersion and latch-synchronized operation in dual-comparator form for test, measurement, and defense electronics.

FAQ

What is the operating temperature range for AD96687BR?

The AD96687BR is rated for industrial operation from –25°C to +85°C. This range is confirmed in the Ordering Guide and Electrical Characteristics tables of the official Analog Devices datasheet (Rev. D). All guaranteed specifications-including propagation delay, input offset voltage, and latch timing-apply across this full temperature span. Derating is not required within these limits, and thermal impedance values (qJA = 92°C/W for SOIC) support reliable operation under continuous load.

Does AD96687BR require external pull-down resistors on its outputs?

Yes, AD96687BR requires external pull-down resistors on all Q and Q outputs because they are open-emitter. The datasheet specifies 50–200 Ω resistors connected to –2.0 V for proper ECL-10K/10KH logic levels. Omitting these resistors results in undefined output states and failure to meet timing or voltage specifications. Termination must match system impedance to prevent ringing on fast edges.

How are the two latch enable inputs configured on AD96687BR?

AD96687BR has two independent latch enable inputs with opposite logic polarities: one is active-low (latch enabled when LOW), the other is active-high (latch enabled when HIGH), as shown in the functional block diagram and pin description. This allows flexible track/hold sequencing-for example, one comparator can be held while the other tracks, enabling interleaved sampling. Both LE inputs must be driven; floating either degrades noise immunity and may cause erratic latching.

Can AD96687BR operate with a single positive supply?

No, AD96687BR cannot operate with only a positive supply. It requires both +5.0 V and –5.2 V rails as specified in the Absolute Maximum Ratings and Electrical Characteristics sections. The input stage and output drivers depend on the negative supply for correct common-mode range (–2.5 V minimum) and ECL-compatible output swing. Attempting single-supply operation will result in non-functional inputs, incorrect output levels, and potential device damage.

What is the significance of 50 ps delay dispersion in AD96687BR?

The 50 ps delay dispersion in AD96687BR quantifies the maximum change in propagation delay when input overdrive varies from 100 mV to 1 V. This low value ensures consistent timing behavior regardless of signal amplitude-critical in applications like time-of-flight measurement or clock recovery where jitter directly impacts accuracy. Unlike comparators with >200 ps dispersion, AD96687BR maintains sub-0.5% timing error across typical overdrive ranges.