Analog Devices Inc. LTC4366ITS8-1#TRMPBF

Overview

LTC4366ITS8-1#TRMPBF from Analog Devices is a high-voltage surge stopper IC that protects downstream loads by regulating output voltage during overvoltage transients up to >500V using an external N-channel MOSFET. It features adjustable 43V output clamping, 9-second internal cool-down timer, latch-off fault behavior (–1 variant), and operates across –40°C to +85°C in an 8-lead TSOT-23 package. It is used in 28V vehicle systems requiring uninterrupted operation during transient surges.

For engineers reviewing the LTC4366ITS8-1#TRMPBF datasheet, LTC4366ITS8-1#TRMPBF pinout, LTC4366ITS8-1#TRMPBF application, or LTC4366ITS8-1#TRMPBF equivalent, key selection considerations include its latch-off fault response (vs auto-retry –2), floating topology support, adjustable overvoltage timer via TIMER pin capacitor, and compatibility with high-voltage DC distribution architectures where MOSFET gate control and thermal safety timing are critical.

Technical Context

The LTC4366ITS8-1#TRMPBF implements a floating architecture: its OUT and BASE pins power internal circuitry from the MOSFET source, isolating logic from input surges. It uses a 1.23V reference-based overvoltage regulation amplifier referenced to OUT, enabling precise clamp voltage setting via FB resistive divider.

It integrates dual shunt regulators (12V on VDD, 5.7V on OUT), a 7.5µA start-up current source, a 2MHz charge pump for 12V-above-source GATE drive, and a 9µA TIMER pin current source that triggers fault latching at 2.8V - all supporting robust operation in >500V transient environments without external bias supplies.

Key Specifications

Pinout & Package

Package: 8-lead plastic TSOT-23 (0.65mm pitch), exposed pad optional to VSS. Thermal resistance θ_JA = 195°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC4366ITS8-2#TRMPBF, the LTC4366ITS8-1#TRMPBF provides deterministic manual reset control essential for safety validation, while TPS26631RGER trades high-voltage scalability and external MOSFET optimization for integration and current-limiting precision at lower voltages.

Availability

LTC4366ITS8-1#TRMPBF is available at Aetrix Electronics and suitable for 28V vehicle systems, avionic DC bus protection, and industrial high-voltage DC distribution requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LTC4366ITS8-1#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 optimized for floating topologies in automotive, avionic, and industrial power systems where >500V transient immunity and MOSFET gate control are required.

FAQ

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

The LTC4366ITS8-1#TRMPBF latches off permanently after an overvoltage fault and requires the SD pin to be toggled (low then high) to reset. In contrast, the LTC4366ITS8-2#TRMPBF automatically retries after a fixed 9-second cool-down period. Both share identical pinout, electrical specs, and operating temperature range (–40°C to +85°C), making them drop-in replacements except for fault-handling behavior.

How does LTC4366ITS8-1#TRMPBF achieve >500V input surge tolerance despite its 12V VDD rating?

The LTC4366ITS8-1#TRMPBF achieves >500V surge tolerance through its floating architecture: internal circuitry (charge pump, regulation amplifier) is powered from the OUT pin - tied to the MOSFET source - rather than directly from the high-voltage input. The VDD pin only supplies a 7.5µA start-up current and is clamped at 12V, while the MOSFET's voltage rating determines the absolute maximum input.

What is the role of the BASE pin on LTC4366ITS8-1#TRMPBF, and when should it be used?

The BASE pin on LTC4366ITS8-1#TRMPBF drives the base of an external PNP transistor to reduce power dissipation in the RSS resistor. It is used when the required RSS value becomes physically large due to high V_REG–5.7V voltage drop; connecting a PNP allows RSS to be scaled up by ~35× (typical β), lowering size and thermal stress without compromising regulation accuracy.

Can LTC4366ITS8-1#TRMPBF regulate output voltage at values other than 43V?

Yes. The LTC4366ITS8-1#TRMPBF regulates output voltage based on the FB resistive divider ratio. With V_FB(REG) = 1.23V (OUT – FB), the clamp voltage is calculated as V_OUT = 1.23V × (1 + R_FB1/R_FB2). For example, using R_FB1 = 12.4kΩ and R_FB2 = 422kΩ yields ~43V; changing R_FB2 to 211kΩ sets clamp at ~22V. The datasheet confirms full adjustability across the operating range.

What thermal considerations apply to the TSOT-23 package of LTC4366ITS8-1#TRMPBF in continuous surge scenarios?

The TSOT-23 package of LTC4366ITS8-1#TRMPBF has θ_JA = 195°C/W. Under sustained overvoltage regulation, power dissipation occurs primarily in the external MOSFET, not the IC - the LTC4366ITS8-1#TRMPBF itself dissipates <15mW in normal operation. However, during 9-second cool-down, internal regulators draw higher current; ensure PCB copper pour under the exposed pad (if connected to VSS) and minimize ambient temperature rise to maintain T_J < 150°C.