Analog Devices Inc. LT1766EFE-5#PBF

Overview

LT1766EFE-5#PBF from Analog Devices (formerly Linear Technology) is a 5V fixed-output, 200kHz monolithic buck switching regulator with 1.5A peak switch current, 5.5V–60V input range, and integrated 0.2Ω NPN power switch. It operates in current-mode control for fast transient response and delivers regulated 5V output in industrial power supplies, battery chargers, and distributed power systems.

For engineers reviewing the LT1766EFE-5#PBF datasheet, LT1766EFE-5#PBF pinout, LT1766EFE-5#PBF application, or LT1766EFE-5#PBF equivalent, key selection factors include its fixed 5V output, thermally enhanced TSSOP-16 package with exposed GND pad, 25μA shutdown current, SYNC capability up to 700kHz, and SENSE pin architecture replacing external feedback dividers.

Technical Context

The LT1766EFE-5#PBF implements current-mode control with cycle-by-cycle peak current limiting and a dedicated SENSE pin tied directly to the 5V output-eliminating external resistors. Its BOOST pin enables saturation of the internal NPN switch via an external capacitor-diode network, achieving low conduction loss (0.2Ω typical) across the full duty cycle range.

It features dual SHDN thresholds (2.38V UVLO and 0.4V deep shutdown), frequency foldback below 0.8V SENSE voltage, and current limit foldback below 0.6V SENSE-providing coordinated short-circuit protection without external circuitry. The VC pin serves as both error amplifier output and current-limit comparator input, supporting loop compensation and override functions.

Key Specifications

Pinout & Package

LT1766EFE-5#PBF is housed in a 16-lead plastic TSSOP package with exposed thermal pad (Pin 17 = GND), optimized for high-power density and thermal performance in space-constrained designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar buck regulator applications.

Compared with LTC3631EMSE-5#PBF and LM5164QDDARQ1, the LT1766EFE-5#PBF uniquely combines 60V input tolerance, fixed 5V SENSE architecture, 1.5A switch current, and thermally optimized TSSOP packaging-making it optimal for industrial and automotive 5V rails where input transients, layout simplicity, and thermal headroom are prioritized over ultra-low IQ or synchronous efficiency.

Availability

LT1766EFE-5#PBF is available at Aetrix Electronics and suitable for industrial power supplies, battery chargers, and automotive body control modules requiring stable component supply, long-term lifecycle support, and guaranteed 0°C to 125°C operation.

Supply support for LT1766EFE-5#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, Inc. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, formed through the acquisition of Linear Technology in 2017.

The LT1766EFE-5#PBF belongs to ADI's legacy Linear Technology power management portfolio, designed specifically for rugged, wide-input-voltage DC/DC conversion in industrial, automotive, and telecommunications infrastructure where reliability, thermal performance, and design simplicity are critical.

FAQ

What is the maximum input voltage rating for the LT1766EFE-5#PBF?

The LT1766EFE-5#PBF has an absolute maximum input voltage rating of 60V on the VIN pin, with guaranteed operation from 5.5V to 60V. This makes it suitable for harsh environments such as 48V industrial buses and automotive systems subject to load dump transients. Exceeding 60V risks permanent damage per Absolute Maximum Ratings.

Does the LT1766EFE-5#PBF require external feedback resistors to set the output voltage?

No-the LT1766EFE-5#PBF features an internal 5V feedback divider and uses Pin 12 as a SENSE input, which must be connected directly to the regulated 5V output. Unlike the adjustable LT1766 version, no external resistors are needed, eliminating associated tolerance errors and saving board space.

How does the BOOST pin function in the LT1766EFE-5#PBF?

The BOOST pin on the LT1766EFE-5#PBF provides a voltage higher than VIN to the base of the internal NPN power switch, enabling saturation and achieving a low 0.2Ω typical on-resistance. It requires an external boost capacitor and diode (e.g., 100V ceramic + Schottky) connected between VIN and BOOST to generate the boosted drive voltage during each switching cycle.

What thermal performance can be expected from the LT1766EFE-5#PBF in a standard PCB layout?

In a typical 2-layer PCB with the exposed GND pad (Pin 17) soldered to a 1-in² copper pour, the LT1766EFE-5#PBF achieves θJC = 10°C/W and θJA ≈ 45°C/W. This allows continuous 1A output at up to 85°C ambient temperature without forced air, verified per the FE package thermal data in the datasheet.

Can the LT1766EFE-5#PBF be synchronized to an external clock, and what is the valid frequency range?

Yes-the LT1766EFE-5#PBF supports external synchronization via the SYNC pin (Pin 14). It accepts logic-level signals (10%–90% duty cycle) from 228kHz to 700kHz, allowing EMI reduction through clock alignment with system timing domains or noise-sensitive interfaces like CAN or ADC sampling clocks.