Analog Devices Inc. LTC4366ITS8-2#TRPBF

Overview

LTC4366ITS8-2#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 >500V, maintains load operation under 43V clamping, supports 9V–>500V input range, features auto-retry fault recovery, and delivers 1.5A continuous current in automotive and industrial DC distribution systems.

For engineers reviewing the LTC4366ITS8-2#TRPBF datasheet, LTC4366ITS8-2#TRPBF pinout, LTC4366ITS8-2#TRPBF application, or LTC4366ITS8-2#TRPBF equivalent, key selection criteria include adjustable overvoltage clamp (via FB divider), 9-second internal cool-down timer, shutdown quiescent current <14µA, TSOT-23-8 package compatibility, and auto-retry behavior distinguishing it from latch-off LTC4366-1 variants.

Technical Context

The LTC4366ITS8-2#TRPBF implements a floating topology where OUT powers internal regulation circuitry and charge pump, enabling operation with input voltages far exceeding its own pin ratings. Its overvoltage regulation amplifier compares FB voltage to a 1.23V reference referenced 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 for adjustable overvoltage timeout, and a 9-second internal cool-down timer after fault. The -2 suffix denotes auto-retry functionality: after fault and cool-down, it autonomously restarts without SD pin intervention.

Key Specifications

Pinout & Package

Package: 8-Lead Plastic TSOT-23 (TS8), exposed pad optional, θJA = 195°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC4366ITS8-1#TRPBF, the LTC4366ITS8-2#TRPBF provides autonomous recovery ideal for remote or inaccessible installations; compared with TPS26631RGER, it trades integration for vastly higher voltage scalability and precision clamp adjustment-enabling protection in domains beyond 60V.

Availability

LTC4366ITS8-2#TRPBF is available at Aetrix Electronics and suitable for 28V vehicle systems, avionic DC distribution, and industrial high-voltage power feeders requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for LTC4366ITS8-2#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 (now part of Analog Devices, Inc., a wholly owned subsidiary of Analog Devices, Inc.) designs high-performance analog, mixed-signal, and digital signal processing ICs for precision, power, and reliability-critical applications.

The LTC4366 product line delivers high-voltage surge protection ICs engineered for floating, ultra-wide-input DC power systems in automotive, aerospace, and industrial infrastructure-prioritizing survivability under extreme transients.

FAQ

What is the key functional difference between LTC4366ITS8-2#TRPBF and LTC4366ITS8-1#TRPBF?

The LTC4366ITS8-2#TRPBF implements auto-retry fault recovery: after an overvoltage event, it enters a 9-second cool-down period and then automatically restarts. In contrast, the LTC4366ITS8-1#TRPBF latches off permanently and requires an external SD pin toggle to clear the fault and resume operation. This makes the -2 variant ideal for unattended or remote deployments where manual reset is impractical.

How does LTC4366ITS8-2#TRPBF achieve >500V input protection despite its 12V VDD rating?

The LTC4366ITS8-2#TRPBF uses a floating architecture: its critical regulation circuitry-including the charge pump and overvoltage amplifier-is powered from the OUT pin, not VDD. Since OUT tracks the input voltage (via the external MOSFET), the IC effectively "rides" the surge. Only VDD and SD pins interface directly with the input rail, and both are internally clamped (VDD to 12V above VSS, SD to 1.5V below VDD), enabling safe operation with input transients far exceeding its absolute maximum ratings.

What determines the overvoltage clamp voltage of LTC4366ITS8-2#TRPBF?

The overvoltage clamp voltage of LTC4366ITS8-2#TRPBF is set by an external resistive divider between OUT and ground, connected to the FB pin. The regulation amplifier maintains OUT–FB = 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 = 1.23V × (1 + 12.4/422) ≈ 43V. This allows precise, application-specific clamping without changing the IC.

Can LTC4366ITS8-2#TRPBF operate with input voltages below 9V?

No-LTC4366ITS8-2#TRPBF requires a minimum input voltage of 9V to ensure reliable start-up. Below this, the VDD shunt regulator cannot establish its 12V rail, and the OUT UVLO2 threshold (4.75V) cannot be reached to enable the charge pump. The minimum start-up voltage depends on RIN, RSS, MOSFET threshold, Schottky drop, and C1 charging dynamics; design equations in the datasheet confirm 9V as the validated lower bound for guaranteed operation across temperature and process variation.

What is the role of the BASE pin on LTC4366ITS8-2#TRPBF?

The BASE pin on LTC4366ITS8-2#TRPBF drives the base of an external PNP transistor used to reduce power dissipation in the RSS resistor. Instead of sinking full shunt current through RSS, the PNP diverts base current (up to ~10µA) while allowing RSS to be increased 30–40×, significantly lowering its wattage requirement. This is especially valuable in high-voltage applications where RSS would otherwise require a physically large, high-wattage resistor.