Analog Devices Inc. LT4356CS-1#TRPBF

Overview

LT4356CS-1#TRPBF from Analog Devices is a high-voltage surge stopper IC that protects downstream loads by regulating output voltage during overvoltage transients (e.g., automotive load dump) via external N-channel MOSFET gate control. It features 4V–80V operating range, 50mV overcurrent sense threshold, 7µA shutdown current, and guaranteed operation to 125°C in SO-16 package. Used in automotive power distribution and industrial hot-swap systems.

For engineers reviewing the LT4356CS-1#TRPBF datasheet, LT4356CS-1#TRPBF pinout, LT4356CS-1#TRPBF application, or LT4356CS-1#TRPBF equivalent, key selection criteria include adjustable output clamp voltage, reverse input protection to –60V, fault timer programmability, and compatibility with back-to-back FET reverse polarity schemes.

Technical Context

The LT4356CS-1#TRPBF implements dual-loop protection: a voltage amplifier servoing the FB pin to 1.25V during overvoltage events, and a current amplifier limiting ΔVSNS to 50mV during overcurrent faults. Both loops drive the GATE pin to regulate the external N-MOSFET's conduction state.

Fault response is adaptive: TMR pin charging current scales with V_DS (VCC–OUT), enabling dynamic safe operating area (SOA) management. Early warning (FLT low at 1.25V) precedes full shutdown (GATE low at 1.35V), with cool-down restart at 0.5V - all timed by a single external capacitor.

Key Specifications

Pinout & Package

LT4356CS-1#TRPBF is housed in a 16-lead plastic SO package (JEDEC MS-012AA). Exposed pad not present. Thermal resistance θ_JA = 100°C/W. Pin 1 marked by notch or dot.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC4365 and TPS26631, LT4356CS-1#TRPBF offers superior high-voltage resilience (80V), programmable fault timing via TMR capacitor, and –60V reverse input tolerance - making it uniquely suited for demanding automotive and ruggedized industrial deployments.

Availability

LT4356CS-1#TRPBF is available at Aetrix Electronics and suitable for automotive load dump protection, industrial hot-swap power distribution, and battery-powered system high-side switching requiring stable component supply and long-term lifecycle assurance.

Supply support for LT4356CS-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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LT4356 family is designed as a robust, high-voltage surge stopper platform for mission-critical power protection - emphasizing wide input range, adaptive fault timing, and reverse polarity survivability in harsh environments.

FAQ

What is the maximum input voltage the LT4356CS-1#TRPBF can withstand?

The LT4356CS-1#TRPBF supports continuous operation from 4V to 80V on its VCC pin. Its absolute maximum rating allows VCC to be pulled down to –60V without damage, enabling direct connection in reverse-battery scenarios. This –60V to 100V tolerance on SHDN and VCC makes LT4356CS-1#TRPBF suitable for automotive and industrial systems exposed to severe transients and polarity reversals.

How does the LT4356CS-1#TRPBF implement overcurrent protection?

The LT4356CS-1#TRPBF monitors the voltage drop between VCC and SNS pins. When ΔVSNS reaches 50mV, its internal current amplifier regulates the GATE pin to hold that threshold, limiting load current. Simultaneously, it sources a V_DS-scaled current into the TMR pin; if TMR reaches 1.25V, FLT asserts, and at 1.35V, GATE pulls low to disable the external MOSFET. This ensures precise, adaptive overcurrent response in LT4356CS-1#TRPBF.

Can the LT4356CS-1#TRPBF be used with P-channel MOSFETs?

No - the LT4356CS-1#TRPBF is specifically designed to drive N-channel MOSFETs in high-side configuration. Its GATE driver is optimized for sourcing gate charge and pulling down with high current (150mA) to rapidly turn off the N-MOSFET during faults. Driving a P-channel device would require inverted logic, level shifting, and incompatible gate drive characteristics - which LT4356CS-1#TRPBF does not support.

What is the purpose of the AOUT and IN+ pins on the LT4356CS-1#TRPBF?

AOUT is the open-collector output of an auxiliary amplifier whose inverting input is tied to an internal 1.25V reference. IN+ is its non-inverting input. Together, they enable configurable functions: as a voltage detection comparator (e.g., undervoltage lockout) or as a linear regulator controller driving an external PNP pass transistor. In LT4356CS-1#TRPBF, these pins provide system-level monitoring and auxiliary regulation without requiring additional ICs.

How does the fault timer in the LT4356CS-1#TRPBF adapt to different overvoltage conditions?

The LT4356CS-1#TRPBF's TMR pin current scales linearly with V_DS (VCC–OUT): from ~2µA at 0.5V to 50µA at 75V during overvoltage. This ensures shorter total fault times for higher V_DS, keeping the external MOSFET within its safe operating area. For example, an 80V surge triggers faster shutdown than a 30V event - a behavior intrinsic to LT4356CS-1#TRPBF's architecture and not achievable with fixed-timer ICs.