Analog Devices Inc. LT1766EGN-5#PBF

Overview

LT1766EGN-5#PBF from Analog Devices (formerly Linear Technology) is a monolithic 200kHz current-mode buck switching regulator with fixed 5V output, 5.5V–60V input range, 1.5A peak switch current, 0.2Ω on-resistance, and thermal-enhanced 16-pin SSOP package. It delivers regulated power in high-voltage industrial DC/DC conversion where input transients exceed standard IC limits.

For engineers reviewing the LT1766EGN-5#PBF datasheet, LT1766EGN-5#PBF pinout, LT1766EGN-5#PBF application, or LT1766EGN-5#PBF equivalent, key selection criteria include fixed 5V output accuracy (±2%), shutdown current (25μA), SYNC frequency range (228–700kHz), and thermal performance of the GN-package exposed-ground layout.

Technical Context

The LT1766EGN-5#PBF implements current-mode control with cycle-by-cycle peak current limiting and internal 200kHz oscillator, enabling fast transient response and stable loop compensation without external slope compensation. Its patented boost-capacitor-driven NPN switch achieves saturation at high VIN, maintaining 1.5A peak current across full duty cycle range.

It integrates a 5V fixed feedback divider (SENSE pin), undervoltage lockout (2.38V SHDN threshold), and dual-mode shutdown (micropower mode at 0.4V). The BIAS pin supports efficiency optimization by sourcing bias current from VOUT when VIN ≫ VOUT, reducing total input-referred quiescent current to 2.4mA typical.

Key Specifications

Pinout & Package

LT1766EGN-5#PBF uses a 16-pin plastic SSOP package (GN) with four corner ground pins and internal GND connections at pins 1, 8, 9, 16. The exposed pad is not present in GN; thermal dissipation relies on PCB copper area under the body and corner GND vias.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC3642EMSE-5#PBF and LM5164QDGSRQ1, LT1766EGN-5#PBF uniquely balances 60V operation, 1.5A current, 200kHz fixed frequency, and external synchronization - making it optimal for industrial 48V systems needing predictable EMI behavior and proven thermal reliability in SSOP.

Availability

LT1766EGN-5#PBF is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, and battery-powered test equipment requiring stable component supply across extended temperature and voltage ranges.

Supply support for LT1766EGN-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 acquired Linear Technology in 2017 and maintains full technical and manufacturing continuity for legacy Linear products including the LT1766 family.

The LT1766 series was designed as a high-voltage, current-mode monolithic buck regulator targeting industrial, automotive, and distributed power applications where input transients exceed 40V and thermal reliability in compact packages is essential.

FAQ

What is the maximum input voltage rating for the LT1766EGN-5#PBF?

The LT1766EGN-5#PBF has an absolute maximum input voltage (VIN) rating of 60V, as specified in the Absolute Maximum Ratings table. Operation up to this limit is supported across the full –40°C to 125°C junction temperature range, with no derating required. This makes LT1766EGN-5#PBF suitable for 48V industrial buses and automotive load-dump conditions.

Does the LT1766EGN-5#PBF require an external feedback resistor network?

No, the LT1766EGN-5#PBF does not require external feedback resistors. It integrates an internal 5V feedback divider, and the FB pin functions as a SENSE input directly connected to the regulated 5V output. This eliminates resistor tolerance errors and temperature drift, ensuring ±2% output accuracy over line, load, and temperature - a key advantage over adjustable versions like LT1766EGN#PBF.

How does the BOOST pin function in the LT1766EGN-5#PBF?

The BOOST pin in LT1766EGN-5#PBF provides a voltage higher than VIN to saturate the internal NPN power switch. It must be connected to VIN + 5V via an external diode and capacitor. This configuration reduces effective switch on-resistance to 0.2Ω, minimizing conduction losses and enabling high efficiency across the full 5.5–60V input range - especially critical at high VIN where traditional buck regulators suffer voltage drop penalties.

What protection features are built into the LT1766EGN-5#PBF?

The LT1766EGN-5#PBF includes cycle-by-cycle current limiting, frequency foldback (5:1 reduction below 0.8V SENSE), current limit foldback (to <1A below 0.6V SENSE), undervoltage lockout (2.38V SHDN threshold), and thermal shutdown. These features collectively limit power dissipation during short-circuit, start-up, or overload events - protecting both LT1766EGN-5#PBF and external components like the catch diode and inductor.

Can the LT1766EGN-5#PBF be synchronized to an external clock?

Yes, the LT1766EGN-5#PBF supports external synchronization via its SYNC pin. It accepts logic-level square waves from 228kHz to 700kHz with 10–90% duty cycle and ≥1.5V amplitude. This allows EMI reduction through deterministic noise placement and avoids beat frequencies in multi-rail systems - a feature not available in many competing fixed-output buck regulators.