Analog Devices Inc. LTC4380CDD-3#TRPBF

Overview

LTC4380CDD-3#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 sustained overvoltage/overcurrent events. It operates from 4V to 72V input, delivers 8µA operating current, features adjustable gate clamp via external Zener, and latches off during faults. Used in 12V/24V automotive power distribution with battery backup.

For engineers reviewing the LTC4380CDD-3#TRPBF datasheet, LTC4380CDD-3#TRPBF pinout, LTC4380CDD-3#TRPBF application, or LTC4380CDD-3#TRPBF equivalent, key selection criteria include its adjustable gate clamp architecture (no internal 31.5V/50V clamp), latchoff fault behavior, –60V reverse input tolerance, 10-pin DFN (3mm × 3mm) package, and AEC-Q100-compliant C-grade temperature range (0°C to 70°C).

Technical Context

The LTC4380CDD-3#TRPBF implements a multiplier-based fault timer where TMR pin current scales with both MOSFET V_DS (via DRN pin) and I_D (via SNS–OUT voltage), enabling dynamic SOA protection proportional to instantaneous power dissipation. Its GATE driver regulates to V_OUT + 11.5V and lacks internal gate-to-GND clamps - requiring external Zener at VCC to set output clamp voltage.

It uses an ON pin comparator (1.05V threshold, 45mV hysteresis) for undervoltage detection and shutdown control, reducing quiescent current to 6µA. The FLT open-drain output asserts low on fault and remains latched until ON is pulsed low ≥100µs or power is cycled - distinguishing it from auto-retry variants (–2/–4).

Key Specifications

Pinout & Package

Package: 10-Lead (3mm × 3mm) Plastic DFN with exposed pad (Pin 11 = GND, optional PCB connection).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC4380CDD-1#TRPBF and LTC4380CDD-2#TRPBF, the LTC4380CDD-3#TRPBF provides full gate clamp adjustability via VCC Zener and deterministic latchoff - making it optimal for safety-critical, custom-voltage, or battery-sensitive applications where controlled shutdown and precise clamping are mandatory.

Availability

LTC4380CDD-3#TRPBF is available at Aetrix Electronics and suitable for automotive load dump protection, reverse battery protection, always-on telematics power supplies, and industrial 24V DC power distribution requiring stable component supply and long-term lifecycle support.

Supply support for LTC4380CDD-3#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 automotive, industrial, communications, and healthcare markets.

The LTC4380 product line delivers robust, low-I_Q surge protection ICs designed specifically for harsh automotive and industrial power environments - emphasizing latchoff safety, reverse polarity resilience, and MOSFET SOA optimization.

FAQ

What is the gate clamp mechanism used in the LTC4380CDD-3#TRPBF?

The LTC4380CDD-3#TRPBF has no internal gate-to-GND clamp. Its gate clamp voltage is set externally by placing a Zener diode between VCC and GND - which defines the maximum GATE voltage as V_ZENER + 13.5V (since GATE is regulated to V_CC + 13.5V). This allows precise, application-specific output clamping (e.g., 27V, 36V, or 45V) without internal fixed thresholds. The LTC4380CDD-3#TRPBF requires SEL tied to GND to disable clamp-select logic.

How does the fault response of the LTC4380CDD-3#TRPBF differ from the LTC4380CDD-2#TRPBF?

The LTC4380CDD-3#TRPBF uses latchoff fault behavior: once tripped by overvoltage or overcurrent, it holds GATE off and FLT low until the ON pin is pulsed low for ≥100µs or power is cycled. In contrast, the LTC4380CDD-2#TRPBF enters automatic cool-down and retry - discharging TMR to 100mV before restarting. This makes the LTC4380CDD-3#TRPBF appropriate for safety-critical systems where unattended recovery is unacceptable.

Can the LTC4380CDD-3#TRPBF be used in reverse battery protection applications?

Yes - the LTC4380CDD-3#TRPBF supports –60V on the VCC pin with no damage, enabling direct reverse battery protection without external diodes. When reverse voltage is applied, the internal circuitry blocks conduction while drawing only leakage current. Combined with its ability to drive back-to-back N-MOSFETs, it eliminates the 0.3–0.5V forward drop and thermal burden of Schottky solutions - a key advantage in always-on automotive modules.

What is the role of the DRN pin in the LTC4380CDD-3#TRPBF?

The DRN pin on the LTC4380CDD-3#TRPBF senses the voltage difference between the external MOSFET's drain and source (V_DS). Connected via R_DRN to OUT, it generates a current proportional to V_DS that multiplies with SNS current inside the IC. This produces a TMR pin current directly proportional to MOSFET power dissipation (V_DS × I_D), enabling adaptive fault timing that shortens trip time under high-stress conditions - critical for staying within MOSFET safe operating area.

Does the LTC4380CDD-3#TRPBF require external components for stability?

Yes - the LTC4380CDD-3#TRPBF requires a minimum 47nF capacitor and 33Ω series resistor at the GATE pin to stabilize the current-limit amplifier loop. Additionally, the OUT pin must be bypassed with ≥22µF low-ESR capacitance placed adjacent to the pin, and the TMR pin requires an X7R ceramic capacitor rated ≥10V (e.g., 8.2µF) to set fault timing and cool-down intervals. These are mandatory for reliable operation per the datasheet layout guidelines.