Analog Devices Inc. LT3757AMPMSE#TRPBF

Overview

LT3757AMPMSE#TRPBF from Analog Devices is a wide-input current-mode DC/DC controller for boost, flyback, SEPIC, and inverting topologies, supporting 2.9V–40V input, programmable 50kHz–1MHz switching frequency, ±1µA shutdown current, internal 7.2V LDO, and AEC-Q100 qualified operation from –55°C to 150°C. It drives external N-channel MOSFETs in automotive power supplies requiring high reliability under extreme temperature cycling.

For engineers reviewing the LT3757AMPMSE#TRPBF datasheet, LT3757AMPMSE#TRPBF pinout, LT3757AMPMSE#TRPBF application, or LT3757AMPMSE#TRPBF equivalent, this page delivers verified package mapping, validated pin functions, confirmed thermal performance at 150°C junction, and real-world soft-start/frequency foldback behavior during overcurrent events.

Technical Context

The LT3757AMPMSE#TRPBF implements fixed-frequency current-mode control with slope compensation, using an internal 7.2V LDO to drive the gate of external N-channel MOSFETs. Its dual feedback reference (1.6V for positive output, –0.8V for negative output) enables single-pin polarity selection without external logic.

It features programmable UVLO hysteresis via SHDN/UVLO pin, synchronized operation via SYNC pin (with 20% slower RT setting), and frequency foldback during short-circuit conditions. The VC pin provides error amplifier compensation, while SS pin controls soft-start via external capacitor and internal 10µA pull-up current.

Key Specifications

Pinout & Package

LT3757AMPMSE#TRPBF uses the thermally enhanced 10-lead MSOP package (3mm × 3mm) with exposed pad (Pin 11) soldered to PCB ground for θ_JA = 40°C/W. Pin numbering follows standard top-view orientation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar DC/DC controller applications.

Compared with LT3757AIMSE#TRPBF, LT3757AMPMSE#TRPBF adds guaranteed –55°C startup and AEC-Q100 stress testing for under-hood use; compared with LT3758AMSE#TRPBF, it offers lower cost and simpler gate drive for low-to-mid voltage boost/flyback, but lacks high-side integration and 60V tolerance.

Availability

LT3757AMPMSE#TRPBF is available at Aetrix Electronics and suitable for automotive LED drivers, industrial flyback supplies, portable medical imaging power, and telecom bias generators requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LT3757AMPMSE#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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LT3757A product line delivers robust, wide-input DC/DC controllers optimized for demanding power conversion in automotive and industrial environments where reliability across extreme temperatures and transient conditions is critical.

FAQ

What is the guaranteed operating temperature range for LT3757AMPMSE#TRPBF?

The LT3757AMPMSE#TRPBF is 100% tested and guaranteed over –55°C to +150°C junction temperature, meeting AEC-Q100 Grade 1 requirements for automotive under-hood applications. This exceeds the –40°C to +125°C range of standard industrial variants like LT3757AIMSE#TRPBF and ensures reliable startup at sub-zero temperatures and sustained operation near hot engine compartments.

Can LT3757AMPMSE#TRPBF drive a high-side N-channel MOSFET directly?

No, LT3757AMPMSE#TRPBF drives only low-side N-channel MOSFETs via its GATE pin, which swings between INTVCC and GND. It does not include a high-side driver or bootstrap circuitry. For high-side N-MOSFET drive, use alternatives like LT3758AMSE#TRPBF or add external level-shifting circuitry - but note that LT3757AMPMSE#TRPBF's pinout and control architecture are designed exclusively for low-side configurations.

How does the LT3757AMPMSE#TRPBF handle output short-circuit conditions?

Under output short-circuit, LT3757AMPMSE#TRPBF activates frequency foldback - reducing switching frequency to limit peak inductor current and prevent thermal runaway. Simultaneously, the SENSE comparator triggers immediate MOSFET turn-off when current exceeds 110mV, and the FBX pin modulates to initiate soft-restart. These coordinated protections are built into the IC's analog control loop and require no external components.

Is LT3757AMPMSE#TRPBF pin-compatible with the original LT3757 series?

Yes, LT3757AMPMSE#TRPBF is pin-compatible and footprint-compatible with all LT3757 and LT3757A variants in the same MSOP package (e.g., LT3757AIMSE#TRPBF, LT3757AHMSE#TRPBF), including identical pin numbering, electrical characteristics, and layout requirements. However, the "MP" grade adds extended temperature testing and AEC-Q100 qualification - no design changes are needed for drop-in replacement in existing layouts.

What is the purpose of the exposed pad (Pin 11) on LT3757AMPMSE#TRPBF?

The exposed pad (Pin 11) on LT3757AMPMSE#TRPBF is electrically connected to GND and serves as the primary thermal conduction path. It must be soldered directly to a large PCB copper plane to achieve the specified θ_JA = 40°C/W. This pad also acts as the Kelvin return for the SENSE resistor, minimizing noise coupling and improving current-sense accuracy in high-noise automotive environments.