Analog Devices Inc. LTC4380IMS-4#TRPBF

Overview

LTC4380IMS-4#TRPBF 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, reverse polarity, and overcurrent events. It features 8µA operating current, 4V–72V input range, adjustable gate clamp (via external Zener), auto-retry fault behavior, and −40°C to +85°C industrial temperature grade in MSOP package. Used in battery-powered telematics and rail-side power distribution.

For engineers reviewing the LTC4380IMS-4#TRPBF datasheet, LTC4380IMS-4#TRPBF pinout, LTC4380IMS-4#TRPBF application, or LTC4380IMS-4#TRPBF equivalent, key selection criteria include gate clamp configurability, MOSFET stress acceleration via TMR-based multiplier, latchoff vs. auto-retry behavior, reverse input protection to −60V, and AEC-Q100-compliant variants for automotive qualification paths.

Technical Context

The LTC4380IMS-4#TRPBF implements a voltage-controlled gate driver with internal 20µA charge pump regulated to V_OUT + 11.5V, enabling high-side N-MOSFET control without bootstrap complexity. Its TMR pin integrates a current proportional to both V_DS (via DRN) and I_D (via SNS), producing a MOSFET power-dissipation-dependent fault timer.

Unlike fixed-clamp versions (−1/−2), the −4 variant lacks internal gate-to-GND clamp - gate voltage is limited only by V_CC + 13.5V compliance and external Zener clamping at V_CC, enabling output clamping from 18V to 86V. Fault recovery uses auto-retry with 15-cycle cool-down on TMR, discharging to 100mV before restart.

Key Specifications

Pinout & Package

Package: 10-Lead Plastic MSOP (3mm × 3mm), exposed pad (GND), θ_JA = 160°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC4380IMS-2#TRPBF, the LTC4380IMS-4#TRPBF trades fixed clamping simplicity for full external adjustability - critical when output voltage must be precisely tuned between 18V–86V. Versus LTC4380HMS-4#TRPBF, it offers identical circuit behavior at lower cost and thermal derating margin for non-extreme environments.

Availability

LTC4380IMS-4#TRPBF is available at Aetrix Electronics and suitable for automotive telematics, industrial rail-side power distribution, avionic sensor conditioning, and battery-backed IoT gateway applications requiring stable component supply across long production lifecycles.

Supply support for LTC4380IMS-4#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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LTC4380 product line delivers robust, low-quiescent-current surge protection for high-reliability power systems - designed specifically for automotive load dump, reverse battery, and hot-swap survivability in harsh environments.

FAQ

What is the gate clamp configuration for LTC4380IMS-4#TRPBF?

The LTC4380IMS-4#TRPBF has no internal gate-to-GND clamp. Its GATE pin is limited only by V_CC + 13.5V compliance. Output clamping is achieved by placing a Zener diode from V_CC to GND - the clamped V_CC directly sets the maximum GATE voltage and thus the output clamp level. This enables precise, application-specific clamping between 18V and 86V. The SEL pin is not functional in the −4 variant and must be tied to GND.

How does the fault timer in LTC4380IMS-4#TRPBF respond to different fault conditions?

The TMR pin current in LTC4380IMS-4#TRPBF scales with both MOSFET V_DS (measured at DRN) and I_D (measured via ΔVSNS), making the fault timer inherently responsive to MOSFET power dissipation. During overvoltage or overcurrent, higher V_DS × I_D increases TMR charging current, reducing turn-off delay to protect SOA. At 1.215V, FLT asserts and GATE turns off. For LTC4380IMS-4#TRPBF, the part then enters auto-retry mode with 15-cycle TMR cool-down before restarting.

Can LTC4380IMS-4#TRPBF be used without an external MOSFET?

No - LTC4380IMS-4#TRPBF is a controller IC and requires an external N-channel MOSFET to function. It provides gate drive, fault sensing, and timing logic but contains no integrated power switch. The MOSFET is selected based on required current, voltage rating, R_DS(on), and SOA - with DRN and SNS pins enabling accurate V_DS and I_D monitoring for intelligent fault response. Attempting to operate LTC4380IMS-4#TRPBF without a MOSFET results in no output regulation or protection.

What is the purpose of the DRN pin in LTC4380IMS-4#TRPBF?

The DRN pin in LTC4380IMS-4#TRPBF senses the voltage difference between the MOSFET's drain and source (V_DS). It sources a current proportional to V_DS through an external resistor R_DRN. This current is multiplied internally with the SNS-derived current (proportional to I_D) to generate a TMR pin current proportional to instantaneous MOSFET power dissipation. This enables adaptive fault timing - severe faults cause faster TMR charging and quicker turn-off, keeping the MOSFET within its safe operating area.

Does LTC4380IMS-4#TRPBF support reverse input protection, and how is it implemented?

Yes - LTC4380IMS-4#TRPBF supports reverse input protection down to −60V on the V_CC pin. Internal protection circuitry allows the device to remain functional and block reverse current flow even when V_CC is pulled to −60V relative to GND, provided ON and SEL are left floating or properly biased. This eliminates the need for an upstream Schottky diode, reducing forward voltage drop, heat generation, and PCB footprint. Reverse current is limited to −0.4mA typical at −60V, per datasheet specifications.