Analog Devices Inc. LTC4366MPDDB-2#TRMPBF

Overview

LTC4366MPDDB-2#TRMPBF 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 >500V. It features auto-retry fault recovery, 9-second internal cool-down timer, adjustable overvoltage clamp (via FB divider), and operates across –55°C to +125°C. Used in 28V vehicle systems and high-voltage DC distribution where uninterrupted load operation during surge events is critical.

For engineers reviewing the LTC4366MPDDB-2#TRMPBF datasheet, LTC4366MPDDB-2#TRMPBF pinout, LTC4366MPDDB-2#TRMPBF application, or LTC4366MPDDB-2#TRMPBF equivalent, key selection criteria include its –55°C to +125°C extended temperature grade, DFN (3mm × 2mm) package with exposed pad, auto-retry (–2) version behavior, 1.23V FB regulation threshold, and 9-second cool-down timing - all critical for rugged industrial and avionic power protection designs.

Technical Context

The LTC4366MPDDB-2#TRMPBF implements a floating topology where OUT powers internal circuitry (charge pump, regulation amplifier), isolating logic from input surges. Its gate drive delivers up to 12V above OUT with fast discharge (200mA pull-down) and charge-pump-assisted turn-on after UVLO2 (4.75V) is reached.

Overvoltage regulation uses a precision 1.23V reference referenced to OUT, comparing FB voltage to trigger gate control. The TIMER pin enables programmable overvoltage duration via external capacitor (311ms/µF), and the –2 variant automatically clears faults after a fixed 9-second cool-down period without external intervention.

Key Specifications

Pinout & Package

Package: 8-lead (3mm × 2mm) plastic DFN with exposed pad (Pin 9), rated TJMAX = 150°C. Exposed pad may be left open or connected to VSS for improved thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC4366HDDB-2#TRMPBF and LTC4366MPDDB-1#TRMPBF, the LTC4366MPDDB-2#TRMPBF uniquely combines military-grade low-temperature operation (–55°C) with autonomous auto-retry recovery - eliminating both external reset circuitry and thermal derating in harsh-environment designs.

Availability

LTC4366MPDDB-2#TRMPBF is available at Aetrix Electronics and suitable for 28V vehicle systems, avionic power distribution, and industrial high-voltage DC bus applications requiring stable component supply under extended temperature and surge stress conditions.

Supply support for LTC4366MPDDB-2#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 (now part of Analog Devices, Inc., a wholly owned subsidiary of Analog Devices, Inc.) designs precision analog, mixed-signal, and digital signal processing ICs for high-reliability applications.

The LTC4366 product line delivers high-voltage surge protection ICs with floating architectures, targeting aerospace, automotive, and industrial systems where input transients exceed 500V and operational continuity is non-negotiable.

FAQ

What is the key functional difference between LTC4366MPDDB-2#TRMPBF and LTC4366MPDDB-1#TRMPBF?

The LTC4366MPDDB-2#TRMPBF implements auto-retry fault recovery: after an overvoltage event triggers shutdown, it automatically clears the fault and resumes operation after a fixed 9-second cool-down period. In contrast, the LTC4366MPDDB-1#TRMPBF latches off permanently until the SD pin is actively toggled low then high. This makes the –2 version ideal for unattended or remote systems where manual reset is impractical.

Does LTC4366MPDDB-2#TRMPBF require an external power supply, or is it self-powered?

The LTC4366MPDDB-2#TRMPBF uses a floating architecture: during normal operation, it draws power from the OUT pin (connected to the MOSFET source), not the input supply. VDD provides only initial gate-charge current during startup. This eliminates need for auxiliary bias supplies and enables operation with input transients far exceeding the IC's absolute maximum ratings - a core design feature confirmed in the datasheet's "Floating Topology" section.

What is the role of the BASE pin on LTC4366MPDDB-2#TRMPBF, and when should it be used?

The BASE pin on LTC4366MPDDB-2#TRMPBF drives the base of an external PNP transistor to reduce power dissipation in the RSS resistor during high-voltage operation. When enabled, it allows use of a higher-value, lower-power RSS resistor - critical in >300V applications where standard resistor sizing would otherwise require physically large components. Tie BASE to VSS if unused, per datasheet Pin Functions section.

How is the overvoltage clamp voltage set for LTC4366MPDDB-2#TRMPBF?

The overvoltage clamp voltage for LTC4366MPDDB-2#TRMPBF is set by an external resistive divider from OUT to ground, connected to the FB pin. The regulation amplifier maintains FB = OUT – 1.23V; therefore, V_CLAMP = 1.23V × (1 + R_FB1/R_FB2). For example, with R_FB1 = 12.4kΩ and R_FB2 = 422kΩ, V_CLAMP ≈ 43V - matching the typical application shown in the datasheet.

What thermal considerations apply to the DFN package of LTC4366MPDDB-2#TRMPBF?

The LTC4366MPDDB-2#TRMPBF uses an 8-lead 3mm × 2mm DFN with exposed pad. Thermal resistance θ_JA is 75°C/W when the exposed pad is soldered to PCB VSS, but rises to 135°C/W if left unconnected. To maintain safe junction temperature under surge conditions, the datasheet mandates proper VSS pad soldering and recommends thermal vias under the pad - directly specified in the Absolute Maximum Ratings table and Package Description.