Analog Devices Inc. LT1720IS8#PBF

Overview

LT1720IS8#PBF from Analog Devices (formerly Linear Technology) is a dual, ultrafast rail-to-rail output comparator optimized for single-supply operation across 2.7V to 6V. It delivers 4.5ns propagation delay at 20mV overdrive, 4mA per comparator supply current, and input common-mode range extending 100mV below ground - enabling precise threshold detection in low-voltage industrial sensor interfaces and high-speed sampling circuits.

For engineers reviewing the LT1720IS8#PBF datasheet, LT1720IS8#PBF pinout, LT1720IS8#PBF application, or LT1720IS8#PBF equivalent, this page provides verified package mapping (SO-8), validated dual-comparator timing behavior, confirmed rail-to-rail TTL/CMOS-compatible outputs, and real-world design context for crystal oscillator circuits, window comparators, and zero-crossing detection.

Technical Context

The LT1720IS8#PBF implements a complementary bipolar differential input stage with internal hysteresis (typ. 3.5mV), enabling stable operation with slow-moving inputs without external feedback. Its rail-to-rail output stage uses PNP/NPN push-pull drivers capable of sourcing 4mA and sinking 10mA while maintaining VOH ≥ VCC – 0.4V and VOL ≤ 0.4V under load.

Pinout is optimized for high-speed layout: inverting inputs (–INA, –INB) are placed opposite outputs (OUTA, OUTB) and shielded by VCC and GND rails to minimize parasitic coupling. The SO-8 package supports full –40°C to +85°C industrial temperature operation with θJA = 200°C/W.

Key Specifications

Pinout & Package

LT1720IS8#PBF is housed in an 8-lead plastic SO (S8) package, rated for –40°C to +85°C operation, with θJA = 200°C/W and JEDEC-standard SOIC footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX961ESA+ and ADCMP600BRMZ, the LT1720IS8#PBF uniquely combines guaranteed sub-5ns delay, –0.1V input capability, and factory-trimmed internal hysteresis - reducing BOM count and layout risk in industrial timing and sensing applications where reliability under marginal signal conditions is essential.

Availability

LT1720IS8#PBF is available at Aetrix Electronics and suitable for industrial sensor interfaces, crystal oscillator circuits, and high-speed sampling systems requiring stable component supply across extended temperature ranges.

Supply support for LT1720IS8#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) designs precision analog, mixed-signal, and power management ICs for high-reliability industrial, automotive, and communications systems.

The LT1720IS8#PBF belongs to Linear's UltraFast comparator family, engineered specifically for single-supply, high-speed decision-making in timing-critical systems where low propagation delay, rail-to-rail output drive, and robust input handling are mandatory.

FAQ

What is the operating temperature range for LT1720IS8#PBF?

The LT1720IS8#PBF is rated for –40°C to +85°C industrial temperature operation, as indicated by the "I" grade suffix in the part number. This range is validated across all key parameters including propagation delay, input offset voltage, and supply current, with thermal resistance θJA = 200°C/W in the SO-8 package.

Does LT1720IS8#PBF require external hysteresis for stable operation?

No, the LT1720IS8#PBF includes internal hysteresis (typ. 3.5mV, min. 2.0mV) that eliminates the need for external positive feedback in most applications. This built-in hysteresis ensures monotonic response to slow-moving or noisy inputs - a key differentiator from comparators like the ADCMP600BRMZ which require external resistors to achieve noise immunity.

Can LT1720IS8#PBF operate from a 3.3V supply?

Yes, the LT1720IS8#PBF is fully specified for 2.7V to 6V single-supply operation. At 3.3V, it maintains 4.5ns typical propagation delay (with derating to 6.5ns max), rail-to-rail output swing (VOH ≥ 2.9V, VOL ≤ 0.4V), and input common-mode range from –0.1V to 2.1V - making it ideal for direct interface with 3.3V microcontrollers and FPGAs.

What is the maximum toggle frequency supported by LT1720IS8#PBF?

The LT1720IS8#PBF supports a maximum toggle frequency of 70MHz at 3V supply and 62.5MHz at 5V supply, measured with 50mV overdrive. This is derived from its 4.5ns propagation delay and matched channel skew (<1.5ns), enabling reliable operation in clock/data recovery and high-speed pulse detection circuits.

How is the LT1720IS8#PBF pinout optimized for high-speed PCB layout?

The LT1720IS8#PBF pinout places sensitive inverting inputs (Pins 2 and 3) opposite outputs (Pins 6 and 7) and shields them with VCC (Pin 8) and GND (Pin 5) rails - minimizing capacitive coupling and ground bounce. This arrangement, combined with recommended layout practices (e.g., ground trace between inputs/outputs), reduces jitter and false triggering in >50MHz applications.