Analog Devices Inc. LT4363CMS-1#PBF

Overview

LT4363CMS-1#PBF 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, limits current via 50mV SNS–OUT sense threshold, and features latch-off fault behavior (LT4363-1 variant) for industrial power rail protection in avionics and hot-swap systems.

For engineers reviewing the LT4363CMS-1#PBF datasheet, LT4363CMS-1#PBF pinout, LT4363CMS-1#PBF application, or LT4363CMS-1#PBF equivalent, this page delivers verified specifications including 4V–80V operating range, 12-lead MSOP package, 1.275V FB reference, 7µA shutdown current, and UV/OV comparator thresholds - all confirmed for the exact LT4363CMS-1#PBF variant.

Technical Context

The LT4363CMS-1#PBF implements dual-fault protection: overvoltage regulation via feedback-controlled GATE drive maintaining 1.275V at FB, and overcurrent limiting by servoing SNS–OUT to 50mV (25mV if OUT < 2V). Fault timing is dynamically scaled by V_CC–V_OUT, with TMR capacitor charging currents ranging from 4µA to 50µA (OV) or 8µA to 260µA (OC).

As the -1 variant, it latches off permanently after fault timeout - GATE and FLT remain low until SHDN is pulsed low ≥100µs. It supports reverse input protection to –60V, withstands 100V+ surges, and integrates precision UV/OV comparators (1.275V threshold, 12mV/7.5mV hysteresis) with independent enable control.

Key Specifications

Pinout & Package

LT4363CMS-1#PBF is housed in a 12-lead plastic MSOP package (4.0mm × 3.0mm × 1.1mm), with exposed pad optional for thermal enhancement. Pin 1 is marked by dot; pin numbering follows standard MSOP convention.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC4365IMS-1#PBF and TPS26631RGER, LT4363CMS-1#PBF provides wider input range (4V–80V), externally adjustable output clamping, dynamic fault timing tied to MOSFET V_DS, and true latch-off behavior - making it uniquely suitable for high-reliability, high-voltage industrial and avionic surge protection where design flexibility and deterministic fault handling are mandatory.

Availability

LT4363CMS-1#PBF is available at Aetrix Electronics and suitable for avionic power distribution, industrial hot-swap modules, and high-side battery switches requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for LT4363CMS-1#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 (now part of Analog Devices, Inc., a wholly owned subsidiary of Analog Devices, Inc.) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors.

The LT4363CMS-1#PBF belongs to the LT® Surge Stopper family, engineered specifically for robust, high-voltage transient protection in mission-critical power systems where latch-off behavior, wide input range, and MOSFET stress-aware fault timing are essential design requirements.

FAQ

What is the key functional difference between LT4363CMS-1#PBF and LT4363CMS-2#PBF?

The LT4363CMS-1#PBF implements latch-off fault behavior: once the TMR pin reaches 1.375V, GATE and FLT remain low until manually reset via SHDN pulse. In contrast, LT4363CMS-2#PBF automatically restarts after TMR discharges to 0.5V, enabling retry functionality. This makes LT4363CMS-1#PBF preferred for safety-critical applications where uncontrolled retries are unacceptable.

How does the LT4363CMS-1#PBF achieve dynamic fault timing based on MOSFET stress?

The LT4363CMS-1#PBF measures V_CC–V_OUT to infer MOSFET V_DS, then scales the TMR capacitor charging current proportionally - from ~4µA at low V_DS to 50µA at 75V V_DS during overvoltage. This ensures shorter fault durations under high stress, keeping the external MOSFET within its Safe Operating Area without requiring complex external compensation.

Can the LT4363CMS-1#PBF be used with P-channel MOSFETs?

No - the LT4363CMS-1#PBF is designed exclusively for N-channel MOSFETs. Its GATE driver is a charge pump that sources current relative to the OUT pin (source), enabling high-side N-MOSFET configuration. Driving a P-channel device would require inverted logic and different gate referencing, which the LT4363CMS-1#PBF does not support.

What is the minimum TMR capacitor value required for stable operation of LT4363CMS-1#PBF?

A minimum 10nF capacitor is required on the TMR pin to compensate the control loop and ensure stable regulation during overvoltage events. Smaller values risk oscillation or premature fault triggering; larger values extend warning and shutdown delays linearly - e.g., 100nF yields ~1.67ms warning and ~9.69ms total regulation time at V_DS = 10V.

Does the LT4363CMS-1#PBF provide reverse polarity protection on its own?

The LT4363CMS-1#PBF itself withstands –60V on VCC and SHDN pins but does not actively block reverse current. For full reverse polarity protection, use back-to-back N-channel MOSFETs controlled by the LT4363CMS-1#PBF - eliminating forward voltage drop versus Schottky diodes while leveraging the IC's robust –60V pin ratings.