Analog Devices Inc. LT4356MPS-1#PBF

Overview

LT4356MPS-1#PBF 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, adjustable fault timer, and −60V to 100V SHDN pin tolerance. It is used in automotive power distribution systems requiring uninterrupted operation under transient stress.

For engineers reviewing the LT4356MPS-1#PBF datasheet, LT4356MPS-1#PBF pinout, LT4356MPS-1#PBF application, or LT4356MPS-1#PBF equivalent, key selection criteria include its 7µA shutdown current (LT4356-1 variant), 125°C guaranteed operation, DFN-12 package with exposed pad, and dual-fault detection (overvoltage + overcurrent) with early warning FLT signal.

Technical Context

The LT4356MPS-1#PBF implements a dual-loop protection architecture: a voltage amplifier servoing the FB pin to 1.25V during overvoltage events, and a current amplifier limiting V_CC–V_SNS to 50mV during overcurrent faults. Its GATE driver uses an internal charge pump to deliver up to 150mA pull-down current and supports 14V above OUT clamping.

Fault timing is dynamically scaled by (V_CC – V_OUT) voltage - increasing timer current linearly from ~2µA at 0.5V to 50µA at 75V for overvoltage, and from 4µA to 260µA for overcurrent - ensuring MOSFET safe operating area compliance across input voltage and fault severity.

Key Specifications

Pinout & Package

LT4356MPS-1#PBF is packaged in a 10-lead plastic MSOP (MS package), with thermal performance θ_JA = 120°C/W and maximum junction temperature of 125°C. The exposed pad is not present in MSOP; no PCB grounding required.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC4365IMS-1#PBF and TPS26631PWPR, the LT4356MPS-1#PBF offers wider input range (4V–80V), external MOSFET control for scalable power handling, dynamic fault timing aligned with MOSFET SOA, and −60V reverse-input tolerance - making it uniquely suited for demanding automotive and industrial surge protection.

Availability

LT4356MPS-1#PBF is available at Aetrix Electronics and suitable for automotive power distribution, industrial hot-swap systems, and intrinsic safety barriers requiring stable component supply across extended temperature ranges and high-reliability qualification.

Supply support for LT4356MPS-1#PBF 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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving precision instrumentation, industrial automation, and automotive markets since 1965.

The LT4356 family is designed as a high-voltage surge stopper IC for protecting sensitive downstream electronics from automotive load dump, industrial transients, and reverse polarity - emphasizing robustness, configurability, and MOSFET SOA compliance.

FAQ

What is the primary function of the LT4356MPS-1#PBF in a power system?

The LT4356MPS-1#PBF acts as a programmable surge stopper that regulates output voltage during overvoltage transients (e.g., automotive load dump) and limits current during overcurrent events by controlling an external N-channel MOSFET. It ensures continuous load operation while protecting both the load and pass transistor from damage - a core capability confirmed in its datasheet's "Surge Stopper" description and block diagram.

How does the LT4356MPS-1#PBF differ from the LT4356-2 variant?

The LT4356MPS-1#PBF implements the LT4356-1 version, featuring 7µA shutdown current and full functional disable during shutdown. In contrast, the LT4356-2 maintains auxiliary amplifier and reference operation at 60µA shutdown current - enabling undervoltage lockout or always-on monitoring. This distinction is explicitly defined in the "FEATURES" and "ELECTRICAL CHARACTERISTICS" sections of the datasheet.

Can the LT4356MPS-1#PBF support reverse input protection?

Yes - the LT4356MPS-1#PBF supports reverse input protection using back-to-back N-channel MOSFETs instead of a Schottky diode, reducing voltage drop and power loss. Its SHDN and SNS pins tolerate −60V, and VCC accepts reverse bias down to −60V, enabling robust reverse-polarity resilience without external components - as stated in the "FEATURES" and "PIN FUNCTIONS" sections.

What package type is used for the LT4356MPS-1#PBF?

The LT4356MPS-1#PBF uses a 10-lead plastic MSOP (MS package), identified in the "ORDER INFORMATION" table as LT4356IMS-1#PBF (industrial grade) and LT4356HMS-1#PBF (high-temp grade). The "MPS" prefix corresponds to the MSOP variant, distinct from DFN ("DE") and SO ("S") packages listed in the same table.

How is overcurrent protection implemented in the LT4356MPS-1#PBF?

The LT4356MPS-1#PBF monitors voltage between VCC and SNS pins, limiting it to 50mV via an internal current sense amplifier. When exceeded, it activates the GATE driver to regulate MOSFET conduction and simultaneously charges the TMR capacitor with a current scaled to (V_CC – V_OUT). If TMR reaches 1.25V, FLT asserts; at 1.35V, GATE pulls low - all confirmed in the "DESCRIPTION", "ELECTRICAL CHARACTERISTICS", and "APPLICATIONS INFORMATION" sections.