Analog Devices Inc. LT4363HMS-1#TRPBF

Overview

LT4363HMS-1#TRPBF from Analog Devices is a high-voltage surge stopper IC that controls an external N-channel MOSFET to regulate output voltage during overvoltage transients up to 100V, limits current via 50mV SNS–OUT sense threshold, and features latch-off fault behavior (LT4363-1 variant) for industrial avionics power protection.

For engineers reviewing the LT4363HMS-1#TRPBF datasheet, LT4363HMS-1#TRPBF pinout, LT4363HMS-1#TRPBF application, or LT4363HMS-1#TRPBF equivalent, this page delivers verified specifications, MSOP-12 package mapping, UV/OV comparator thresholds, fault timer behavior, and real-world hot-swap and battery-system use cases - all confirmed from Analog Devices' official Rev. C datasheet.

Technical Context

The LT4363HMS-1#TRPBF implements dual-loop protection: a voltage amplifier regulates GATE to hold FB at 1.275V during overvoltage, while a current amplifier maintains ΔVSNS = 50mV (or 25mV if OUT < 2V) during overcurrent. Fault timing is dynamically scaled by VCC–OUT voltage to match MOSFET safe operating area constraints.

It integrates precision UV (1.275V threshold, 12mV hysteresis) and OV (1.275V threshold, 7.5mV hysteresis) comparators, a 14V GATE clamp, and a shutdown pin tolerant to –60V to 100V. The LT4363-1 variant latches off after fault timeout and requires active SHDN reset; no auto-retry occurs.

Key Specifications

Pinout & Package

LT4363HMS-1#TRPBF uses a 12-lead plastic MSOP package (4.0mm × 3.0mm × 1.1mm), rated for –40°C to +125°C operation. Thermal resistance θ_JA = 135°C/W. Exposed pad is not present in MSOP variant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar surge protection applications.

Compared with LT4363IMS-1#TRPBF, LT4363HMS-1#TRPBF enables deployment in higher ambient temperatures without derating, while versus LT4363HDE-1#TRPBF it trades thermal efficiency for mechanical compatibility and assembly flexibility in non-high-volume designs.

Availability

LT4363HMS-1#TRPBF is available at Aetrix Electronics and suitable for avionic power distribution, industrial hot-swap modules, and battery-powered safety systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LT4363HMS-1#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. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and aerospace markets.

The LT4363 product line delivers rugged, high-voltage surge protection ICs designed specifically for mission-critical power systems where reliability under extreme electrical stress is non-negotiable.

FAQ

What is the key functional difference between LT4363HMS-1#TRPBF and LT4363HMS-2#TRPBF?

The LT4363HMS-1#TRPBF implements latch-off fault behavior: once the TMR pin reaches 1.375V and the MOSFET turns off, GATE and FLT remain low until SHDN is actively pulsed low for ≥100µs. In contrast, LT4363HMS-2#TRPBF automatically restarts after cool-down (TMR falling to 0.5V), making it suitable for non-safety-critical retry applications. This distinction is hardwired and cannot be altered externally.

Can LT4363HMS-1#TRPBF operate with a 3.3V logic-controlled SHDN signal?

No - the SHDN threshold is 0.4V (max) for activation and 2.1V (min) for release, so a 3.3V GPIO can directly drive SHDN high but requires a series resistor or level translator to ensure voltage stays ≤0.4V when asserting shutdown. Pulling SHDN to GND with a 10kΩ resistor is acceptable; direct 3.3V-to-GND switching may exceed sink capability during transition.

How does the LT4363HMS-1#TRPBF achieve reverse input protection without a Schottky diode?

LT4363HMS-1#TRPBF controls two back-to-back N-channel MOSFETs in series between VCC and OUT. When reverse voltage is applied, both MOSFET body diodes block conduction, and the IC keeps GATE low to prevent channel turn-on. This achieves <10mΩ reverse path resistance versus ~0.4V diode drop - improving efficiency and eliminating thermal runaway risk in battery systems.

What is the minimum TMR capacitor value required for stable operation of LT4363HMS-1#TRPBF?

A minimum 10nF capacitor is required on the TMR pin to compensate the control loop and prevent oscillation during regulation. Smaller values risk instability in voltage or current limiting modes; larger values extend fault timing linearly (e.g., 1µF yields ~97ms regulation time at V_DS = 75V). Ceramic X7R or C0G types are recommended for temperature stability.

Does LT4363HMS-1#TRPBF support adjustable overvoltage threshold independent of the FB divider?

No - the overvoltage clamp voltage is set solely by the FB resistive divider (e.g., 27V in typical application), referenced to the internal 1.275V bandgap. The OV pin (present only on LT4363-2 variants) provides *inhibition* of retry after fault, not adjustment of clamp level. For programmable OV threshold, a separate comparator circuit driving the UV/OV pins is required.