Analog Devices Inc. LT4363CDE-2#TRPBF

Overview

LT4363CDE-2#TRPBF from Analog Devices is a high-voltage surge stopper IC that controls an external N-channel MOSFET to regulate output voltage during overvoltage transients up to 150V, provides adjustable 50mV current limit sensing, features 1.275V precision FB reference, and supports 4V–80V input range - used in avionic power rails and industrial hot-swap systems.

For engineers reviewing the LT4363CDE-2#TRPBF datasheet, LT4363CDE-2#TRPBF pinout, LT4363CDE-2#TRPBF application, or LT4363CDE-2#TRPBF equivalent, key selection criteria include fault timer adjustability via TMR capacitor, LT4363-2 auto-retry behavior after cool-down, OV/UV comparator thresholds (1.275V), GATE drive capability (13V above OUT), and DFN-12 (4mm × 3mm) package thermal performance (θJA = 43°C/W).

Technical Context

The LT4363CDE-2#TRPBF implements dual-fault protection: overvoltage regulation via feedback-controlled GATE drive maintaining 1.275V at FB, and overcurrent limiting by servoing SNS–OUT differential to 50mV (25mV when OUT < 2V). Fault timing is dynamically scaled by V_DS = V_CC – V_OUT, with TMR current ranging from 4µA (V_DS ≤ 0.5V) to 50µA (V_DS = 75V) in overvoltage mode.

Unlike the LT4363-1 latch-off variant, the LT4363-2 version automatically restarts after TMR discharges to 0.5V following cool-down (VTMR(H) = 4.3V → VTMR(R) = 0.5V), with retry duty cycle limited to ≤2% under 80V overvoltage. OV pin (present only on -2 variants) inhibits retry while >1.275V, preventing oscillation during sustained overvoltage.

Key Specifications

Pinout & Package

LT4363CDE-2#TRPBF is housed in a 12-lead (4mm × 3mm) plastic DFN package with exposed thermal pad (Pin 13, connected to GND). The package delivers θ_JA = 43°C/W and operates from 0°C to 70°C (C-grade).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LT4363IDE-2#TRPBF and LT4363HDE-2#TRPBF, the LT4363CDE-2#TRPBF offers identical surge protection architecture and auto-retry behavior but is optimized for cost-sensitive commercial applications within 0°C–70°C ambient, making it ideal for indoor industrial controls and test equipment where extended temperature grades are unnecessary.

Availability

LT4363CDE-2#TRPBF is available at Aetrix Electronics and suitable for avionic power protection, industrial hot-swap systems, and high-side battery switch applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LT4363CDE-2#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 aerospace markets.

The LT4363 family was designed as a high-voltage surge stopper IC to replace discrete protection circuits with integrated, precision-controlled N-MOSFET gate drivers - targeting applications demanding reliable operation under extreme voltage transients and reverse polarity conditions.

FAQ

What is the key functional difference between LT4363CDE-2#TRPBF and LT4363CDE-1#TRPBF?

The LT4363CDE-2#TRPBF implements auto-retry behavior after fault cool-down: once the TMR pin discharges to 0.5V, the GATE pin re-enables the external MOSFET. In contrast, the LT4363CDE-1#TRPBF latches off permanently until manually reset via SHDN pulse. This makes LT4363CDE-2#TRPBF suitable for unattended systems requiring autonomous recovery from transient overvoltage or overcurrent events.

How does the LT4363CDE-2#TRPBF protect against reverse input voltage?

The LT4363CDE-2#TRPBF withstands –60V on VCC, SHDN, UV, and OV pins without damage. When reverse voltage is applied, internal protection structures block conduction while leakage remains below –4mA. Combined with back-to-back N-MOSFET configuration enabled by UV/OV comparators, LT4363CDE-2#TRPBF eliminates need for external reverse-battery diodes - reducing voltage drop and power loss in battery-powered systems.

What is the role of the OV pin on the LT4363CDE-2#TRPBF?

The OV pin is exclusive to LT4363-2 variants and serves as an overvoltage inhibit input. When voltage at OV exceeds 1.275V, the LT4363CDE-2#TRPBF blocks automatic retry even after TMR discharges to 0.5V. This prevents oscillatory "motorboating" during sustained overvoltage conditions. If unused, OV must be tied to GND; leaving it floating may cause undefined behavior.

Can the LT4363CDE-2#TRPBF regulate output voltage to a specific value like 24V?

Yes. The LT4363CDE-2#TRPBF regulates output using the FB pin referenced to a precision 1.275V internal bandgap. To set V_OUT = 24V, use a resistor divider from OUT to GND where R1/(R1+R2) = 1.275V/24V. For example, R2 = 10kΩ and R1 = 168.2kΩ yields 24.0V nominal output. The FB input current is ±1µA, so divider current should exceed 100× this (≥100µA) for accuracy.

What thermal considerations apply to the LT4363CDE-2#TRPBF in DFN-12 package?

The LT4363CDE-2#TRPBF in DFN-12 (4mm × 3mm) package has θ_JA = 43°C/W with proper PCB copper pour under the exposed pad (Pin 13, GND). To maintain junction temperature ≤125°C at 80V input and 500mA load, ensure ≥2cm² of 2-oz copper connected to the exposed pad, minimize trace resistance to GND, and avoid enclosing the device in sealed enclosures without airflow. Derate power dissipation linearly above 70°C ambient.