Analog Devices Inc. LTC4380CMS-4#PBF

Overview

LTC4380CMS-4#PBF from Analog Devices is a low-quiescent-current surge stopper IC that controls an external N-channel MOSFET to protect downstream loads from automotive load dump, input overvoltage (up to 250Vpk), and overcurrent events. It features adjustable gate clamp voltage, 8µA operating current, 4V–72V input range, and auto-retry fault behavior. Used in 12V/1A systems with output clamped at 27V during surge.

For engineers reviewing the LTC4380CMS-4#PBF datasheet, LTC4380CMS-4#PBF pinout, LTC4380CMS-4#PBF application, or LTC4380CMS-4#PBF equivalent, key selection criteria include gate clamp configurability, MOSFET stress-accelerated fault timing, reverse input protection to –60V, latchoff vs. auto-retry behavior, and AEC-Q100 qualification for automotive surge protection.

Technical Context

The LTC4380CMS-4#PBF implements a multiplier-based fault timer where TMR pin current scales with both V_DS (via DRN pin) and I_D (via SNS–OUT differential), enabling MOSFET power-dissipation–proportional turn-off timing. Its GATE driver regulates to V_OUT + 11.5V and lacks internal gate-to-GND clamp-requiring external Zener clamping on VCC for output voltage limiting.

This variant (–4 suffix) supports auto-retry fault recovery with cool-down cycling and uses SEL pin tied to GND for fixed configuration. It operates across 0°C to 70°C ambient, integrates undervoltage detection on ON pin (1.05V threshold), and delivers 6µA shutdown current when ON is pulled low.

Key Specifications

Pinout & Package

Package: 10-Lead Plastic MSOP (3mm × 3mm), RoHS-compliant, exposed pad (GND).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC4380CMS-4#PBF, the IMS-4 and HMS-4 variants retain identical electrical behavior and auto-retry timing but extend operational temperature range-enabling deployment in harsher thermal environments without circuit redesign or layout change.

Availability

LTC4380CMS-4#PBF is available at Aetrix Electronics and suitable for automotive load dump protection, industrial power supply input hardening, and battery-powered telematics requiring stable component supply across production lifecycles.

Supply support for LTC4380CMS-4#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, automotive, and communications markets.

The LTC4380 product line delivers robust, low-IQ surge protection ICs designed specifically for automotive-grade transient suppression and high-reliability industrial power front-ends.

FAQ

What is the gate clamp architecture of the LTC4380CMS-4#PBF?

The LTC4380CMS-4#PBF is an LTC4380-4 variant with no internal gate-to-GND clamp. Its GATE pin is regulated to V_OUT + 11.5V and clamped only to V_CC + 13.5V. Output voltage limiting requires an external Zener diode on the VCC pin - for example, a 27V Zener sets ~27V output clamp in 12V systems. This architecture enables flexible, application-specific overvoltage protection without fixed internal thresholds.

How does the fault timer in LTC4380CMS-4#PBF respond to MOSFET stress?

The LTC4380CMS-4#PBF uses a multiplier-based fault timer where TMR pin current scales with both V_DS (measured at DRN) and I_D (measured via SNS–OUT). Higher MOSFET power dissipation increases TMR charging rate, reducing fault timeout - e.g., a severe short causes faster turn-off than a mild overvoltage. This keeps the external MOSFET within its safe operating area without fixed-time delays.

Does LTC4380CMS-4#PBF support reverse input protection?

Yes, LTC4380CMS-4#PBF withstands –60V on the VCC pin without damage, enabling direct reverse-battery connection protection. No external Schottky diode is required - the IC internally blocks reverse current flow while maintaining 6µA shutdown current. This simplifies front-end design and eliminates forward voltage drop and thermal losses associated with discrete diode solutions.

What is the difference between LTC4380CMS-4#PBF and LTC4380CMS-2#PBF?

LTC4380CMS-4#PBF and LTC4380CMS-2#PBF share identical pinout and package but differ in gate clamp and fault behavior: the –4 version has no internal gate clamp (requires external Zener) and uses auto-retry; the –2 version includes selectable 31.5V/50V internal gate clamp and also uses auto-retry. The –4 offers greater output voltage flexibility; the –2 provides simpler implementation for standard 12V/24V clamp points.

Can LTC4380CMS-4#PBF drive back-to-back MOSFETs for reverse polarity protection?

Yes, LTC4380CMS-4#PBF's GATE pin can drive back-to-back N-channel MOSFETs configured as an ideal diode, eliminating the 0.3–0.7V forward drop and heat generation of Schottky solutions. The IC's low 8µA operating current and –60V reverse tolerance make it ideal for this topology - especially in battery-powered systems where efficiency and reverse protection are both critical.