Analog Devices Inc. LT1766IGN#TRPBF

Overview

LT1766IGN#TRPBF from Analog Devices (formerly Linear Technology) is a 200kHz monolithic step-down switching regulator IC designed for high-voltage industrial power conversion. It accepts 5.5V–60V input, delivers up to 1.5A peak switch current with 0.2Ω on-resistance, maintains constant frequency via current-mode control, and features 1.2V feedback reference for adjustable output voltage. It is used in distributed power systems requiring robust regulation under wide input transients.

For engineers reviewing the LT1766IGN#TRPBF datasheet, LT1766IGN#TRPBF pinout, LT1766IGN#TRPBF application, or LT1766IGN#TRPBF equivalent, key selection factors include its 60V max input rating, thermally enhanced 16-pin SSOP package with exposed ground pad, cycle-by-cycle current limiting, and compatibility with external synchronization from 228kHz to 700kHz.

Technical Context

The LT1766IGN#TRPBF implements current-mode control with an internal 200kHz oscillator, enabling fast transient response and stable loop behavior across wide duty cycles. Its patented circuitry maintains peak switch current over full duty cycle range, and it uses a BOOST pin-driven saturating NPN switch architecture to achieve low conduction loss (0.2Ω typical).

It integrates all control logic, error amplifier (gm = 2000 μmho), VC clamp (0.9V–2.1V), shutdown comparator (2.38V UVLO, 0.4V deep shutdown), and thermal protection. The BIAS pin enables efficiency optimization by sourcing bias current from the regulated output when VIN ≫ VOUT.

Key Specifications

Pinout & Package

The LT1766IGN#TRPBF is housed in a 16-lead plastic SSOP package (GN grade) with four corner GND pins and internal exposed pad (Pin 17) soldered to PCB ground for thermal management. θ_JA = 85°C/W, θ_JC (Pin 8) = 25°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC3631EMSE#PBF and LM5164QDDARQ1, the LT1766IGN#TRPBF uniquely combines 60V input, 1.5A capability, external BOOST control for saturation optimization, and full-frequency synchronization-making it optimal for industrial 48V systems demanding robustness and design flexibility.

Availability

LT1766IGN#TRPBF is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, and distributed telecom power systems requiring stable component supply, long-term lifecycle support, and guaranteed performance across –40°C to +125°C.

Supply support for LT1766IGN#TRPBF 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 technologies, formed through the acquisition of Linear Technology in 2017.

The LT1766IGN#TRPBF belongs to ADI's legacy Linear Technology high-voltage monolithic buck regulator product line, engineered specifically for rugged industrial and transportation power conversion where wide input range, thermal resilience, and fault tolerance are critical.

FAQ

What is the maximum input voltage rating for the LT1766IGN#TRPBF?

The LT1766IGN#TRPBF 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 direct connection to 48V industrial buses and automotive battery systems subject to load-dump transients. Exceeding 60V risks permanent damage per Absolute Maximum Ratings.

Does the LT1766IGN#TRPBF require an external BOOST capacitor, and why?

Yes, the LT1766IGN#TRPBF requires an external BOOST capacitor (and associated diode) connected between BOOST and SW pins. This network generates a voltage higher than VIN to fully saturate the internal NPN power switch, reducing its effective on-resistance to 0.2Ω and minimizing conduction losses-critical for high-efficiency operation at high input voltages.

What is the function of the SHDN pin on the LT1766IGN#TRPBF, and what are its threshold voltages?

The SHDN pin on the LT1766IGN#TRPBF provides dual-threshold control: a 2.38V threshold enables undervoltage lockout (UVLO) to prevent startup until VIN reaches a safe level, and a 0.4V threshold forces deep shutdown with only 25μA supply current. Leaving SHDN open enables default operation via internal bias current.

Can the LT1766IGN#TRPBF be synchronized to an external clock, and what is its sync frequency range?

Yes, the LT1766IGN#TRPBF supports external synchronization via its SYNC pin, accepting logic-level signals from 228kHz to 700kHz with 10%–90% duty cycle. This feature allows EMI reduction in multi-regulator systems and precise timing alignment in synchronized power architectures.

What package type and thermal characteristics does the LT1766IGN#TRPBF use?

The LT1766IGN#TRPBF uses a 16-lead plastic SSOP (GN package) with four corner GND pins and internal exposed pad (Pin 17) that must be soldered to PCB ground. Its thermal resistance is θ_JA = 85°C/W and θ_JC (Pin 8) = 25°C/W, enabling reliable 1.5A operation in industrial environments without additional heatsinking.