Analog Devices Inc. LT1720IMS8#PBF

Overview

LT1720IMS8#PBF from Analog Devices (formerly Linear Technology) is a dual, ultrafast rail-to-rail output comparator optimized for single-supply 3V/5V operation with 4.5ns propagation delay at 20mV overdrive, 4mA per comparator supply current, and input common-mode range extending 100mV below ground to 1.2V below VCC. It is used in high-speed threshold detection, crystal oscillator interfaces, and pulse stretching circuits where low power and small footprint are critical.

For engineers reviewing the LT1720IMS8#PBF datasheet, LT1720IMS8#PBF pinout, LT1720IMS8#PBF application, or LT1720IMS8#PBF equivalent, key selection factors include guaranteed 4.5ns delay at 20mV overdrive, internal 3.5mV hysteresis, rail-to-rail TTL/CMOS-compatible outputs, –40°C to +85°C industrial temperature grade, and MSOP-8 package compatibility with space-constrained PCB layouts.

Technical Context

The LT1720IMS8#PBF implements a complementary bipolar input stage with internal hysteresis, enabling stable operation with slow-moving inputs without external feedback. Its pinout isolates inverting inputs from outputs using power rails as shields, minimizing parasitic coupling in high-speed layouts.

It delivers symmetric rail-to-rail output drive (VOH = VCC – 0.4V at 4mA, VOL = 0.4V at 10mA), supports 2.7V–6V supply operation, and maintains sub-nanosecond skew (<1.5ns) between channels-critical for window comparators and zero-crossing detection requiring matched timing.

Key Specifications

Pinout & Package

LT1720IMS8#PBF is housed in an 8-lead plastic MSOP package (3mm × 3mm, 0.85mm height), thermally rated to TJMAX = 150°C with θJA = 230°C/W. The package supports fine-pitch surface-mount assembly and provides adequate thermal dissipation for continuous dual-comparator operation at 4mA/channel.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LMH7322MA/NOPB and ADCMP600BRMZ-REEL, the LT1720IMS8#PBF uniquely combines dual-channel integration, internal hysteresis, sub-ground input capability, and industrial temperature rating in a compact MSOP-8 package-making it optimal for cost-sensitive, space-constrained industrial sensing and timing applications.

Availability

LT1720IMS8#PBF is available at Aetrix Electronics and suitable for crystal oscillator interfacing, high-speed threshold detection, pulse stretching, and zero-crossing detection requiring stable component supply across industrial temperature ranges.

Supply support for LT1720IMS8#PBF 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 Linear Technology in 2017 and maintains its precision analog portfolio, including high-performance comparators, op amps, and voltage references.

The LT1720IMS8#PBF belongs to Linear's UltraFast™ comparator family, designed specifically for single-supply, high-speed signal conditioning in instrumentation, communications, and industrial control systems.

FAQ

What is the maximum toggle frequency supported by the LT1720IMS8#PBF?

The LT1720IMS8#PBF supports a maximum toggle frequency of 62.5MHz at 5V supply and 70.0MHz at 3V supply when driven with 50mV overdrive. This is derived from its 4.5ns propagation delay and matched channel timing, making it suitable for clock regeneration and high-speed data slicing applications where deterministic edge placement is required.

Does the LT1720IMS8#PBF require external hysteresis for stable operation?

No, the LT1720IMS8#PBF includes internal hysteresis of typical 3.5mV, which prevents oscillation and chatter on slow-moving or noisy inputs. This eliminates the need for external positive feedback resistors in most threshold detection applications, simplifying design and reducing component count compared to comparators lacking built-in hysteresis.

Can the LT1720IMS8#PBF operate with input voltages below ground?

Yes, the LT1720IMS8#PBF supports an input common-mode range extending 100mV below ground (–0.1V) when VCC ≥ 2.7V. This enables direct interfacing with AC-coupled sensors, transformer outputs, or other signals that swing negative relative to system ground-without requiring level-shifting circuitry or bias networks.

What is the thermal performance of the LT1720IMS8#PBF in MSOP-8 package?

The LT1720IMS8#PBF in MSOP-8 package has a junction-to-ambient thermal resistance (θJA) of 230°C/W and a maximum junction temperature (TJMAX) of 150°C. At 4mA per comparator (8mA total) and 5V supply, power dissipation is ~40mW, resulting in a worst-case junction rise of ~9.2°C above ambient-well within safe operating limits for industrial environments.

How does the LT1720IMS8#PBF compare to the LT1720CDD#PBF variant?

The LT1720IMS8#PBF and LT1720CDD#PBF share identical electrical specifications and comparator core functionality. The key differences are package (MSOP-8 vs. 3mm×3mm DFN) and temperature grade: LT1720IMS8#PBF is rated for –40°C to +85°C (I-grade), while LT1720CDD#PBF is 0°C to +70°C (C-grade) in a smaller DFN package. Both use the same pinout and biasing scheme.