Analog Devices Inc. LTC3637MPMSE#TRPBF

Overview

LTC3637MPMSE#TRPBF from Analog Devices (formerly Linear Technology) is a high-efficiency, wide-input 76V step-down DC/DC regulator with integrated 350mΩ P-channel MOSFET, 12µA no-load quiescent current, and programmable 0.24A–2.4A peak current limit. It delivers up to 1A output current, supports 0.8V–VIN adjustable or factory-fixed 1.8V/3.3V/5V outputs, and operates across –55°C to 150°C for harsh-environment industrial and avionics power rails.

For engineers reviewing the LTC3637MPMSE#TRPBF datasheet, LTC3637MPMSE#TRPBF pinout, LTC3637MPMSE#TRPBF application, or LTC3637MPMSE#TRPBF equivalent, this page provides verified package mapping (16-lead MSE), confirmed pin functions (including RUN, OVLO, ISET, VPRG1/VPRG2), thermal performance data (θJA = 45°C/W), and two validated alternative parts with documented functional and application differences.

Technical Context

The LTC3637MPMSE#TRPBF uses Burst Mode® control with hysteretic feedback to achieve high efficiency across 10µA–1A load range, enabling ultra-low quiescent operation without external compensation. Its internal 0.8V ±1% reference and precision RUN/OVLO comparators (1.21V rising threshold, 110mV hysteresis) support robust input voltage monitoring and controlled start-up.

Peak inductor current is set via a resistor from ISET to GND (200mA–2A range), directly determining maximum average output current (50% of peak). The 100% duty-cycle dropout capability and P-channel high-side switch allow regulation down to VIN – 65V under high-dV/dt conditions, with mandatory 10mA minimum load above 65V differential.

Key Specifications

Pinout & Package

Package: 16-lead plastic MSOP (MSE16), 3mm × 5mm × 1.1mm profile, exposed thermal pad (Pin 17) soldered to PCB ground plane. θJA = 45°C/W, θJC = 10°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down regulator applications.

Compared with LTC3637HMSE#TRPBF, the LTC3637MPMSE#TRPBF adds guaranteed –55°C startup and operation for extreme cold environments; compared with LTC3637MPDHC#TRPBF, it trades 2°C/W higher θJA for MSOP compatibility with legacy footprints and simplified assembly.

Availability

LTC3637MPMSE#TRPBF is available at Aetrix Electronics and suitable for industrial control supplies, avionics power distribution, and downhole oil & gas sensors requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for LTC3637MPMSE#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 acquired Linear Technology in 2017 and maintains its high-reliability analog and power management portfolio with rigorous qualification standards.

The LTC3637 belongs to Linear's high-voltage monolithic buck regulator family, designed specifically for ruggedized power conversion in aerospace, defense, and industrial systems where input transients, wide temperature swings, and long-term reliability are critical.

FAQ

What is the minimum load requirement for LTC3637MPMSE#TRPBF when operating with high input-to-output voltage differential?

The LTC3637MPMSE#TRPBF requires a minimum 10mA output load when the input-to-output voltage differential exceeds 65V (e.g., 76V_IN → 5V_OUT) to maintain regulation under all conditions, including shutdown mode. Without this load, the minimum sustainable output voltage drops to VIN – 65V. This requirement is specified in the Applications Information section and applies regardless of temperature grade.

How does the ISET pin function in LTC3637MPMSE#TRPBF, and what is its impact on maximum output current?

The ISET pin on the LTC3637MPMSE#TRPBF sources a 5µA (active) or 1µA (sleep) current to set the peak inductor current threshold via an external resistor to GND. Since the LTC3637MPMSE#TRPBF uses a hysteretic control architecture, the maximum average output current equals one-half the programmed peak current. For example, a 2.4A peak limit yields 1.2A max average output, but the datasheet guarantees 1A continuous operation across temperature.

What is the purpose of the FBO pin on LTC3637MPMSE#TRPBF, and how is it typically used in system design?

The FBO (Feedback Comparator Output) pin on the LTC3637MPMSE#TRPBF is an open-drain output that pulls low when the feedback voltage falls below the 0.8V reference, indicating loss of regulation. With a typical 20µA pull-up and 70Ω pull-down, it serves as a simple power-good flag for microcontrollers or sequencers to monitor output health without additional circuitry.

Can LTC3637MPMSE#TRPBF operate in 100% duty cycle mode, and under what conditions does this occur?

Yes, the LTC3637MPMSE#TRPBF supports 100% duty cycle operation using its internal P-channel high-side MOSFET. This occurs when VIN approaches VOUT, allowing continuous conduction to maintain regulation. However, power dissipation increases significantly below ~10V input due to higher R_DS(on) and output current - thermal design must account for this in dropout scenarios.

What are the key thermal design considerations for LTC3637MPMSE#TRPBF in the MSE16 package?

The LTC3637MPMSE#TRPBF in MSE16 has θJA = 45°C/W and requires the exposed thermal pad (Pin 17) to be soldered to a solid PCB ground plane. For 1A continuous operation at 76V_IN, thermal simulation shows junction temperature rise of ~65°C above ambient - sufficient headroom below the 150°C TJMAX. Layout must minimize thermal resistance via multiple vias under the pad and avoid isolating copper pours.