Analog Devices Inc. LTC4366ITS8-1#TRPBF

Overview

LTC4366ITS8-1#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, shutdown current <14µA, and operates across –40°C to +85°C. Used in 28V vehicle systems and high-voltage DC distribution where uninterrupted operation during transient surges up to >500V is required.

For engineers reviewing the LTC4366ITS8-1#TRPBF datasheet, LTC4366ITS8-1#TRPBF pinout, LTC4366ITS8-1#TRPBF application, or LTC4366ITS8-1#TRPBF equivalent, key selection criteria include its floating topology support, adjustable overvoltage timer, latch-off fault behavior (LTC4366-1 variant), N-MOSFET gate drive capability, and TSOT-23 package compatibility with high-voltage bias resistor networks.

Technical Context

The LTC4366ITS8-1#TRPBF implements a floating architecture: its OUT and BASE pins are powered from the MOSFET source, enabling operation with input voltages exceeding 500V while isolating internal circuitry from surge stress. It uses a 1.23V precision reference at the FB pin to regulate output via feedback divider, with fast 60ns response to overvoltage events.

It integrates dual shunt regulators (12V on VDD, 5.7V on OUT), a 2MHz charge pump for 12V-above-source GATE drive, and a 9µA TIMER pin current source that triggers fault latching when voltage reaches 2.8V - corresponding to user-defined overvoltage duration. The -1 suffix denotes latch-off behavior after fault, requiring SD pin reset.

Key Specifications

Pinout & Package

Package: 8-lead plastic TSOT-23 (0.65mm pitch), exposed pad (Pin 9) optional connection 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#TRPBF, the LTC4366ITS8-1#TRPBF provides deterministic fault isolation for safety-critical use; compared with TPS26631RGER, it delivers scalable high-voltage resilience and design flexibility at the cost of external MOSFET integration.

Availability

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

Supply support for LTC4366ITS8-1#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 precision analog, mixed-signal, and digital signal processing ICs for high-reliability applications.

The LTC4366 product line delivers high-voltage surge protection with floating architecture and programmable timing, targeting automotive, avionic, and industrial systems where input transients exceed 500V and load continuity is essential.

FAQ

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

The LTC4366ITS8-1#TRPBF latches off permanently after an overvoltage fault and requires an SD pin reset to resume operation, ensuring deliberate human or system intervention. In contrast, the LTC4366ITS8-2#TRPBF automatically retries after its 9-second cool-down period. This makes the -1 variant appropriate for safety-critical applications like avionics or off-highway equipment where unattended restart could pose risk, while the -2 suits telecom or industrial systems prioritizing uptime.

How does LTC4366ITS8-1#TRPBF achieve operation with input voltages exceeding 500V?

The LTC4366ITS8-1#TRPBF achieves >500V operation through a floating architecture: its OUT and BASE pins are powered from the source of the external N-channel MOSFET, not the high-voltage input rail. Internal shunt regulators (12V on VDD, 5.7V on OUT) isolate sensitive circuitry, while external resistors (RSS, RIN) scale bias currents proportionally to input voltage. This eliminates dependence on internal pin voltage ratings and shifts surge handling to the external MOSFET's breakdown limit.

What is the role of the TIMER pin on LTC4366ITS8-1#TRPBF, and how is it configured?

The TIMER pin on LTC4366ITS8-1#TRPBF sets the maximum duration of overvoltage regulation before fault latching. It is charged at 9µA; when voltage reaches 2.8V, the part enters fault state. A capacitor (CT) from TIMER to VSS defines timing: CT = 3.2 nF/ms. For example, a 100nF capacitor yields ~31ms regulation window. Leaving TIMER open defaults to 1µs - suitable only for very fast transients where immediate shutdown is desired.

Can LTC4366ITS8-1#TRPBF be used with P-channel MOSFETs?

No, LTC4366ITS8-1#TRPBF is designed exclusively for N-channel MOSFETs. Its GATE driver sources current to pull the gate 12V above the source (OUT), which is only compatible with N-MOSFET enhancement-mode operation. Driving a P-channel device would require reverse polarity gate control relative to source - a function not supported by the internal charge pump or regulation amplifier architecture.

What is the minimum input voltage required for reliable startup of LTC4366ITS8-1#TRPBF?

The minimum startup voltage for LTC4366ITS8-1#TRPBF depends on external resistor values and MOSFET threshold but is typically ≥18V. Startup requires sufficient voltage across RIN to generate ≥9µA (IVDD(STHI)) to charge the GATE, and across RSS to provide ≥45µA (IVSS(AMP)) to bring OUT above 4.75V (UVLO2). With standard values (RIN = 324kΩ, RSS = 46.4kΩ, VTH ≈ 3V), VIN(MIN) ≈ 22V - verified in typical application Figure 1.