Analog Devices Inc. LT4363CS-2#PBF

Overview

LT4363CS-2#PBF from Analog Devices is a high-voltage surge stopper IC that regulates output during overvoltage transients by controlling an external N-channel MOSFET gate. It provides adjustable 27V output clamping, 50mV current-sense threshold, and 0.25µs overvoltage turn-off time, enabling uninterrupted operation in avionic power systems subjected to >100V surges.

For engineers reviewing the LT4363CS-2#PBF datasheet, LT4363CS-2#PBF pinout, LT4363CS-2#PBF application, or LT4363CS-2#PBF equivalent, this page delivers verified specifications including 4V–80V operating range, 7µA shutdown current, 16-pin SO package, OV/UV comparator thresholds (1.275V), and LT4363-2 auto-retry behavior with <1% duty cycle during faults.

Technical Context

The LT4363CS-2#PBF implements dual-fault protection using independent voltage and current regulation loops: a precision amplifier maintains 1.275V at FB during overvoltage, while a current-limit servo holds ΔVSNS = 50mV (25mV when OUT < 2V). Its fault timer uses VCC–OUT voltage to dynamically scale TMR charging current-4µA to 50µA for overvoltage, 8µA to 260µA for overcurrent-optimizing MOSFET safe operating area.

Unlike the latch-off LT4363-1, the LT4363CS-2#PBF features automatic restart after cool-down: TMR discharges to 0.5V, then GATE pulls high only if OV < 1.275V, preventing motorboating under sustained overvoltage. The 16-pin SO package includes dedicated OV and UV pins, with SHDN tolerating –60V to 100V and SNS–OUT differential up to ±30V.

Key Specifications

Pinout & Package

LT4363CS-2#PBF is housed in a 16-lead plastic SO package (S package) with exposed thermal pad not present. Pin 1 is bottom-left corner; pin numbering follows standard SO convention: pins 1–8 on bottom row left-to-right, pins 9–16 on top row right-to-left.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LT4363HS-2#PBF and LT4363IMS-2#PBF, the LT4363CS-2#PBF offers optimal cost-performance balance for commercial-temperature applications requiring the proven thermal reliability of the 16-pin SO package, while maintaining full functional compatibility across the LT4363-2 family.

Availability

LT4363CS-2#PBF is available at Aetrix Electronics and suitable for avionic power distribution, industrial hot-swap systems, and high-side battery switch applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LT4363CS-2#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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, communications, automotive, and aerospace markets.

The LT4363 family is designed as high-voltage surge stoppers for mission-critical power systems, emphasizing robust fault handling, precise regulation, and seamless integration with external N-channel MOSFETs in harsh environments.

FAQ

What is the key functional difference between LT4363CS-2#PBF and LT4363CS-1#PBF?

The LT4363CS-2#PBF implements auto-retry fault recovery: after overvoltage or overcurrent shutdown, it automatically restarts once the TMR pin discharges to 0.5V and the OV pin falls below 1.275V. In contrast, the LT4363CS-1#PBF latches off permanently until manually reset via SHDN pulse. This makes LT4363CS-2#PBF ideal for unattended systems where manual intervention is impractical.

How does the LT4363CS-2#PBF achieve dynamic fault timing based on MOSFET stress?

The LT4363CS-2#PBF measures VCC–OUT voltage to infer MOSFET V_DS, then scales the TMR charging current accordingly: 4µA at low V_DS (≤0.5V) up to 50µA during 75V overvoltage. This ensures shorter fault timeouts under high-stress conditions, keeping the external MOSFET within its safe operating area without fixed-timer conservatism.

Can the LT4363CS-2#PBF be used with P-channel MOSFETs?

No - the LT4363CS-2#PBF is specifically designed to drive N-channel MOSFETs in high-side configuration, leveraging its charge-pump GATE driver referenced to OUT. It lacks the level-shifting architecture required for efficient P-channel gate control. For P-MOSFET applications, Analog Devices recommends the LTC4365 or LTC4366 families instead.

What is the minimum TMR capacitor value required for stable operation of LT4363CS-2#PBF?

A minimum 10nF capacitor is required between TMR and GND to compensate the control loop and ensure stable regulation during overvoltage events. Smaller values risk oscillation or false triggering; larger values extend fault timing linearly (e.g., 6.8µF yields ~97ms total fault timer per datasheet Figure 1).

Does the LT4363CS-2#PBF provide reverse input protection natively?

The LT4363CS-2#PBF does not include integrated reverse-blocking elements but enables robust reverse input protection by controlling two back-to-back N-channel MOSFETs. This configuration achieves <0.1V forward drop versus 0.3–0.5V for Schottky diodes, reducing power loss and heat generation while supporting –60V reverse tolerance on VCC and SHDN pins.