Analog Devices Inc. LTC4366CDDB-1#TRPBF

Overview

LTC4366CDDB-1#TRPBF from Analog Devices is a high-voltage surge stopper IC that protects downstream loads by regulating output voltage during overvoltage transients using an external N-channel MOSFET. It features adjustable 43V output clamping, 9-second internal cool-down timer, latch-off fault behavior (–1 version), and operates across 9V to >500V input range in automotive 28V systems.

For engineers reviewing the LTC4366CDDB-1#TRPBF datasheet, LTC4366CDDB-1#TRPBF pinout, LTC4366CDDB-1#TRPBF application, or LTC4366CDDB-1#TRPBF equivalent, this page delivers verified functional identity, validated DFN-8 package mapping, confirmed 8-pin terminal roles, exact overvoltage regulation threshold (1.23V below OUT), and real-world timing behavior for surge protection design in high-reliability DC distribution.

Technical Context

The LTC4366CDDB-1#TRPBF implements a floating topology where its internal circuitry is powered from the MOSFET source (OUT pin), enabling operation with input surges exceeding 500V - limited only by external MOSFET and resistor ratings. Its overvoltage regulation amplifier compares FB to a precise 1.23V reference relative to OUT, driving GATE to clamp output at user-defined voltage.

It integrates dual shunt regulators (12V on VDD, 5.7V on OUT), a 9µA TIMER pin current source, and a 200mA fast pull-down on GATE during overvoltage events. The –1 variant latches off after fault and requires SD pin toggle to reset, distinguishing it from auto-retry –2 versions.

Key Specifications

Pinout & Package

Package: 8-lead (3mm × 2mm) plastic DFN with exposed thermal pad (Pin 9, optional VSS connection).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC4366CDDB-1#TRPBF, the LTC4366IDDB-1#TRPBF extends thermal capability without changing layout or BOM footprint, while LTC4366CDDB-2#TRPBF replaces manual fault clearing with autonomous recovery - both preserve identical surge handling, clamping precision, and DFN-8 integration.

Availability

LTC4366CDDB-1#TRPBF is available at Aetrix Electronics and suitable for automotive 28V systems, avionic DC bus protection, and industrial DC power feeds requiring stable component supply with guaranteed long-term manufacturability.

Supply support for LTC4366CDDB-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 (now part of Analog Devices, Inc., a wholly owned subsidiary of Analog Devices, Inc.) designs high-performance signal processing and power management ICs for demanding industrial, automotive, and aerospace applications.

The LTC4366 product line delivers high-voltage surge protection ICs with floating architectures, enabling reliable operation in >500V transient environments where conventional protectors fail - specifically targeting ruggedized DC distribution systems.

FAQ

What is the key functional difference between LTC4366CDDB-1#TRPBF and LTC4366CDDB-2#TRPBF?

The LTC4366CDDB-1#TRPBF latches off permanently after an overvoltage fault and requires an SD pin toggle to resume operation, ensuring explicit fault acknowledgment. In contrast, the LTC4366CDDB-2#TRPBF automatically retries after a fixed 9-second cool-down period. Both share identical clamping accuracy, pinout, DFN-8 package, and 0°C to 70°C temperature rating - only fault recovery behavior differs.

How does LTC4366CDDB-1#TRPBF achieve >500V input surge tolerance despite its 12V VDD rating?

The LTC4366CDDB-1#TRPBF uses a floating architecture: its internal circuitry is powered from the MOSFET source (OUT pin), not the input rail. This isolates logic from input surges - only external components (MOSFET, RSS, RIN) experience high voltage. The 12V VDD clamp protects the start-up circuit, while the 5.7V OUT clamp safeguards regulation circuitry, enabling safe operation with input transients far exceeding absolute maximum ratings.

What is the exact overvoltage regulation threshold voltage referenced to OUT for LTC4366CDDB-1#TRPBF?

The LTC4366CDDB-1#TRPBF regulates output by holding the FB pin at precisely 1.23V below the OUT pin voltage (VFB(REG) = 1.23V, min 1.193V, max 1.267V over temperature). This reference is internally generated and stable across 0°C to 70°C, enabling accurate, resistor-divider-based clamping - e.g., 43V clamp with RFB1/RFB2 = 12.4kΩ/422kΩ as shown in the典型 application.

Does LTC4366CDDB-1#TRPBF require external components to function, and which are mandatory?

Yes - LTC4366CDDB-1#TRPBF requires four mandatory external components: an N-channel MOSFET (e.g., IXTK90N25L2), FB resistive divider (RFB1/RFB2), TIMER capacitor (sets overvoltage duration), and OUT bypass capacitor (≥0.22µF). Optional components include RSS (voltage-dropping resistor), RIN (start-up resistor), and BASE-connected PNP for reduced RSS power dissipation - all specified in the datasheet's typical application schematic.

What thermal performance can be expected from LTC4366CDDB-1#TRPBF in its DFN-8 package?

The LTC4366CDDB-1#TRPBF in 3mm × 2mm DFN has θJA = 75°C/W when the exposed pad is soldered to PCB VSS, rising to 135°C/W if unsoldered. At 1.5A load with 43V clamp and 28V input, power dissipation in the external MOSFET dominates - the IC itself dissipates <150mW under normal operation. Proper PCB copper area under the exposed pad is essential to maintain junction temperature below 150°C during sustained surge events.