Analog Devices Inc. LT3001ES5#TRMPBF

Overview

LT3001ES5#TRMPBF from Analog Devices is a micropower isolated flyback converter IC with integrated 1.2A/65V DMOS switch, operating from 4V to 36V input and delivering up to 4W isolated output power. It regulates output voltage via primary-side flyback waveform sampling-eliminating opto-isolators and third windings-and sets VOUT using a single external resistor (RFB). Used in telecom and industrial auxiliary power supplies.

For engineers reviewing the LT3001ES5#TRMPBF datasheet, LT3001ES5#TRMPBF pinout, LT3001ES5#TRMPBF application, or LT3001ES5#TRMPBF equivalent, key selection criteria include boundary/low-ripple burst mode operation, EN/UVLO hysteresis programmability, RFB regulation current accuracy (100 µA), minimum load requirement (<0.5% full output), and TSOT-23 thermal performance (θJA = 215°C/W).

Technical Context

The LT3001ES5#TRMPBF implements current-mode control in boundary conduction mode at heavy loads and low-ripple Burst Mode® at light loads, enabling high efficiency across 6mA–1.15A output range. Its internal error amplifier samples reflected output voltage during zero secondary current, ensuring accurate regulation without secondary-side feedback components.

It integrates all high-voltage circuitry-including 65V-rated SW pin, precise 1.228V EN/UVLO threshold with 14mV hysteresis, and internal compensation-into a 5-lead TSOT-23 package. The RFB pin draws 100 µA (±2.5%) to set output voltage as VOUT = 100 µA × RFB × NPS − VF, where NPS is transformer turns ratio.

Key Specifications

Pinout & Package

LT3001ES5#TRMPBF is housed in a 5-lead plastic TSOT-23 package (S5), measuring 2.90 mm × 1.60 mm × 0.85 mm, with θJA = 215°C/W. The exposed pad is not electrically connected.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar isolated flyback controller applications.

Compared with UCC28740DR and MAX17690ATP+T, the LT3001ES5#TRMPBF uniquely integrates the 65V switch and eliminates opto-isolation-reducing solution size by ≥30% and simplifying safety certification-while trading off maximum input voltage and synchronous rectification support.

Availability

LT3001ES5#TRMPBF is available at Aetrix Electronics and suitable for industrial PLC I/O isolation, automotive body control modules, and medical patient monitoring sensors requiring stable component supply, long-lifecycle availability, and guaranteed -40°C to 125°C operation.

Supply support for LT3001ES5#TRMPBF 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. is a global semiconductor leader specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision instrumentation, industrial, automotive, and communications markets.

The LT3001ES5#TRMPBF belongs to Analog Devices' µModule® and isolated power controller product line, designed specifically to simplify certified isolated power design by integrating regulation, switching, and protection into minimal-footprint packages.

FAQ

What is the minimum load requirement for stable regulation with the LT3001ES5#TRMPBF?

The LT3001ES5#TRMPBF requires less than 0.5% of full output power as minimum load-approximately 6 mA for a 5V/1A design-to ensure sufficient switching activity for accurate flyback waveform sampling. Below this, output voltage may rise due to insufficient energy delivery for proper regulation sampling. A Zener diode (e.g., 6V/1W) can serve as a passive minimum load if preloading is undesirable.

How does the LT3001ES5#TRMPBF achieve regulation without an opto-isolator or third winding?

The LT3001ES5#TRMPBF samples the isolated output voltage directly from the primary-side flyback pulse on the SW pin during zero secondary current-enabled by boundary or discontinuous conduction mode. This eliminates need for opto-isolators or auxiliary windings while maintaining ±2% output accuracy across line, load, and temperature. The RFB pin draws 100 µA to scale the reflected voltage into precise VOUT.

What is the purpose of the RFB pin on the LT3001ES5#TRMPBF, and how is it used?

The RFB pin on the LT3001ES5#TRMPBF sinks a precise 100 µA current to set output voltage via VOUT = 100 µA × RFB × NPS − VF. It connects to the transformer primary SW node through a single external resistor. Because RFB draws a trimmed current with ±2.5% tolerance and low temperature drift, it enables accurate, resistor-programmed outputs without trimming or secondary feedback components.

Can the LT3001ES5#TRMPBF operate reliably at its absolute maximum input voltage of 42V?

No-the LT3001ES5#TRMPBF is rated for continuous operation up to 36V input; 42V is the absolute maximum rating for transient survival only. Sustained operation above 36V risks exceeding the 65V SW pin rating when combined with transformer leakage spikes. For 42V nominal inputs, use external clamping or select a controller with higher VIN rating such as the MAX17690.

What thermal considerations apply to the LT3001ES5#TRMPBF in a 5-lead TSOT-23 package?

The LT3001ES5#TRMPBF has θJA = 215°C/W in the TSOT-23 package, meaning junction temperature rises sharply with power dissipation. At 4W output, typical losses (~0.8W) raise TJ by ~172°C above ambient-requiring careful PCB layout: 25 mm² copper pour under the exposed pad (if present), minimal trace length on SW/VIN, and forced air cooling for >2W continuous operation. Derate output power above 85°C ambient.