Analog Devices Inc. LT4363IMS-2#TRPBF

Overview

LT4363IMS-2#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 150V, limits current via 50mV SNS–OUT sense threshold, and features auto-retry (LT4363-2) with adjustable fault timer. It operates from 4V to 80V input, supports –60V reverse input protection, and is used in avionic power rails requiring robust hot-swap and transient resilience.

For engineers reviewing the LT4363IMS-2#TRPBF datasheet, LT4363IMS-2#TRPBF pinout, LT4363IMS-2#TRPBF application, or LT4363IMS-2#TRPBF equivalent, key selection considerations include its 12-lead MSOP package, –40°C to 85°C operating range, 1.275V FB reference, 5µs overcurrent response, and distinct LT4363-2 auto-restart behavior versus LT4363-1 latch-off.

Technical Context

The LT4363IMS-2#TRPBF implements dual-fault protection: overvoltage regulation via feedback-controlled GATE drive maintaining 1.275V at FB, and overcurrent limiting by servoing SNS–OUT to 50mV (25mV if OUT < 2V). Its fault timer uses VCC–OUT–dependent current sources charging the TMR capacitor - 4–50µA for overvoltage, ~5× higher for overcurrent - enabling SOA-aware timing.

It integrates precision UV/OV comparators (1.275V thresholds, 12mV/7.5mV hysteresis), a 14V GATE clamp, 7µA shutdown current, and open-collector FLT/ENOUT outputs. The LT4363-2 variant automatically restarts after cool-down (TMR falling to 0.5V), inhibited only if OV > 1.275V - preventing motorboating under sustained overvoltage.

Key Specifications

Pinout & Package

LT4363IMS-2#TRPBF is housed in a 12-lead plastic MSOP package (MS grade) with exposed pad (GND-connected, optional). Pin functions are electrically identical to the DFN/SO variants but mapped to the MSOP footprint.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar surge protection and current-limiting applications.

Compared with LTC4365IMS-2#TRPBF and TPS26631RGER, LT4363IMS-2#TRPBF uniquely supports 80V continuous input, user-adjustable output clamping, and dual UV/OV supervision - making it the only option for ruggedized 28V/48V avionic and industrial systems facing MIL-STD-1275/ISO-16750 transients.

Availability

LT4363IMS-2#TRPBF is available at Aetrix Electronics and suitable for avionic power distribution, industrial hot-swap modules, and intrinsic safety barriers requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for LT4363IMS-2#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 semiconductors, serving aerospace, industrial, communications, and automotive markets.

The LT4363IMS-2#TRPBF belongs to ADI's Linear Technology surge protection product line, designed specifically for high-reliability power systems requiring robust transient immunity, precise current limiting, and intelligent fault recovery in harsh environments.

FAQ

What is the key functional difference between LT4363IMS-2#TRPBF and LT4363IMS-1#TRPBF?

The LT4363IMS-2#TRPBF implements auto-retry fault recovery: after overvoltage or overcurrent shutdown, it automatically restarts once the TMR capacitor discharges to 0.5V and the OV pin falls below 1.275V. In contrast, the LT4363IMS-1#TRPBF latches off permanently and requires a SHDN pulse (≥100µs low) to reset. This makes LT4363IMS-2#TRPBF ideal for unattended systems needing self-recovery from transient faults.

Can LT4363IMS-2#TRPBF be used with P-channel MOSFETs?

No - LT4363IMS-2#TRPBF is explicitly designed to drive N-channel MOSFETs configured as high-side switches. Its GATE driver is a charge pump that pulls the gate 13V above the OUT node, enabling full enhancement of N-channel devices. Driving a P-channel MOSFET would require inverted logic and negative gate drive capability, which LT4363IMS-2#TRPBF does not provide.

How is the overvoltage clamp voltage set for LT4363IMS-2#TRPBF?

The overvoltage clamp voltage is set externally using a resistive divider from OUT to GND, connected to the FB pin. With a precise 1.275V internal reference at FB, the clamp voltage equals 1.275V × (1 + R1/R2), where R1 is the upper resistor (OUT to FB) and R2 is the lower resistor (FB to GND). This allows full programmability - e.g., 27V clamp uses R1/R2 ≈ 19.4.

What is the minimum TMR capacitor value required for stable operation of LT4363IMS-2#TRPBF?

A minimum 10nF capacitor is required between TMR and GND to ensure loop stability and prevent oscillation during regulation. Smaller values risk instability and erratic fault timing; larger values increase warning and shutdown delays linearly. For example, a 6.8µF capacitor yields ~100ms total fault timer duration under typical VDS conditions.

Does LT4363IMS-2#TRPBF support reverse polarity protection without additional components?

LT4363IMS-2#TRPBF itself does not provide reverse polarity protection, but it enables robust implementation using back-to-back N-channel MOSFETs - replacing lossy Schottky diodes. Its SHDN, UV, and OV pins tolerate –60V, and the GATE driver supports synchronous control of both FETs. This configuration achieves <50mV forward drop and full reverse blocking, with no extra ICs required.