Analog Devices Inc. LTC4368IDD-1#WPBF

Overview

LTC4368IDD-1#WPBF from Analog Devices is a bidirectional electronic circuit breaker and UV/OV/reverse supply protection controller for 2.5V–60V input systems. It controls back-to-back N-channel MOSFETs to isolate loads during faults, features ±50mV forward/reverse current sense thresholds (LTC4368-1 variant), 80µA operating current, and AEC-Q100 qualification for automotive surge protection.

For engineers reviewing the LTC4368IDD-1#WPBF datasheet, LTC4368IDD-1#WPBF pinout, LTC4368IDD-1#WPBF application, or LTC4368IDD-1#WPBF equivalent, key selection criteria include reverse current threshold (–50mV), –40°C to +85°C temperature range, 10-lead 3mm × 3mm DFN package, and compatibility with hot-swap and AC-blocking designs requiring robust fault recovery timing.

Technical Context

The LTC4368IDD-1#WPBF implements dual high-speed comparators (1µs propagation) for UV and OV detection with 25mV hysteresis, and two independent overcurrent comparators: +50mV for forward faults and –50mV for reverse faults. Its gate driver delivers up to 13.1V enhancement above VOUT with fast (2µs) and slow (275µs) turn-off paths, plus a fixed 32ms turn-on delay for AC line rejection and noise immunity.

It integrates a charge pump referenced to VOUT, supports adjustable UV/OV thresholds via external resistive dividers with <1nA input leakage, and provides latch-off or auto-retry behavior on forward overcurrent based on RETRY pin configuration. Reverse fault recovery requires VIN–VOUT ≥ 100mV before reconnection.

Key Specifications

Pinout & Package

Package: 10-lead (3mm × 3mm) Plastic DFN with exposed pad (optional ground connection). Pin numbering follows top-view standard for LGTH marking.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bidirectional overvoltage/overcurrent protection applications.

Compared with LTC4368IDD-2#WPBF, the LTC4368IDD-1#WPBF provides stricter reverse polarity response ideal for automotive battery interfaces, while TPS26631RGER offers integration at the expense of bidirectionality and extended fault range - making LTC4368IDD-1#WPBF the sole choice for AEC-Q100-compliant, fully bidirectional protection.

Availability

LTC4368IDD-1#WPBF is available at Aetrix Electronics and suitable for automotive battery protection, industrial PLC input conditioning, and energy storage system interfaces requiring stable component supply with AEC-Q100 traceability and long-term lifecycle support.

Supply support for LTC4368IDD-1#WPBF 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 healthcare markets.

The LTC4368 product line delivers integrated UV/OV/reverse/overcurrent protection controllers for harsh environments, designed specifically to replace discrete protection solutions in automotive and industrial power entry applications.

FAQ

What is the reverse overcurrent threshold for LTC4368IDD-1#WPBF?

The LTC4368IDD-1#WPBF has a fixed reverse overcurrent threshold of –50mV (SENSE–VOUT), as specified in the datasheet Rev. C, Electrical Characteristics table (ΔVSENSE,R for LTC4368-1). This value is factory-trimmed and applies across the full –40°C to +85°C temperature range. It enables precise detection of reverse current flow, such as during battery misconnection, without requiring external calibration. The LTC4368IDD-1#WPBF uses this threshold to trigger immediate gate turn-off and hold isolation until VIN–VOUT ≥ 100mV.

Does LTC4368IDD-1#WPBF support hot-swap of 48V supplies?

No, LTC4368IDD-1#WPBF does not support hot-swap of 48V supplies. The datasheet explicitly states "VOUT cannot be hot swapped with supplies above 24V" due to internal charge pump and gate drive limitations. While the device operates up to 60V and protects against transients up to 100V, live insertion of inputs >24V risks unreliable turn-on behavior or false UV/OV triggering. For 48V hot-swap applications, a different controller with higher hot-swap rating or external pre-charge circuitry is required. LTC4368IDD-1#WPBF remains valid for 12V/24V automotive and industrial hot-swap use cases.

How is the 32ms turn-on delay implemented in LTC4368IDD-1#WPBF?

The 32ms turn-on delay in LTC4368IDD-1#WPBF is a fixed internal timer activated after UV and OV faults clear and SHDN is asserted high. It debounces the input supply to reject 50Hz/60Hz AC ripple and transient noise, ensuring only stable DC enables the gate charge pump. This delay is not programmable and occurs before any gate drive is applied. It is documented in the Block Diagram (page 8) as "DELAY TIMERS" and confirmed in the Applications Information section (page 11) as filtering "line noise" and preventing "chattering of power at the load." The delay applies identically for UV, OV, and initial power-up sequences in LTC4368IDD-1#WPBF.

Can LTC4368IDD-1#WPBF drive 100V-rated MOSFETs safely?

Yes, LTC4368IDD-1#WPBF can safely drive 100V-rated MOSFETs when used within its specified absolute maximum ratings. Its GATE pin supports –40V to VIN+14V, and VIN is rated up to 100V during fault conditions. When driving high-V_DS MOSFETs, ensure the external gate resistor (RGATE) is sized per datasheet guidance (e.g., 22kΩ) to stabilize fast pull-down and prevent oscillation. The gate driver's 13.1V enhancement above VOUT ensures sufficient V_GS for enhancement-mode N-MOSFETs even at low VOUT. LTC4368IDD-1#WPBF's internal protection logic prevents gate drive activation outside the valid UV/OV window, safeguarding MOSFETs from overvoltage stress.

Is the exposed pad on the LTC4368IDD-1#WPBF DFN package required to be grounded?

No, the exposed pad on the LTC4368IDD-1#WPBF DFN package is optional for grounding. According to the PIN FUNCTIONS section (page 7), "The exposed pad may be left open or connected to device ground." Connecting it to GND improves thermal performance (θ_JA = 43°C/W) but is not electrically mandatory for functionality. Leaving it unconnected does not affect UV/OV/OC protection behavior, gate drive accuracy, or fault reporting. However, for automotive or high-temperature industrial use, grounding the pad is strongly recommended to maintain junction temperature below 150°C under full load. The LTC4368IDD-1#WPBF operates reliably in either configuration.