Analog Devices Inc. LTC4249AV-2#PBF

Overview

LTC4249AV-2#PBF from Analog Devices is a 65V dual-channel electronic circuit breaker (ECB) with precision current monitoring, auto-retry fault response, and integrated 75mΩ N-channel MOSFET switches. It delivers independent overcurrent protection for two high-voltage loads, features 5% accurate analog current monitor outputs (IMON1/IMON2), supports voltage sequencing in GaN PA bias control, and operates across –40°C to 125°C.

For engineers reviewing the LTC4249AV-2#PBF datasheet, LTC4249AV-2#PBF pinout, LTC4249AV-2#PBF application, or LTC4249AV-2#PBF equivalent, key selection considerations include its auto-retry fault behavior (vs latch-off variants), 1.2A adjustable ECB threshold, filtered primary OC detection (50µs), fast secondary OC response (2µs), and compatibility with high-voltage RF power amplifier arrays requiring load isolation and reverse current detection.

Technical Context

The LTC4249AV-2#PBF implements dual independent ECB channels with separate EN1/EN2 enable inputs, RDY1/RDY2 open-drain status outputs, and IMON1/IMON2 analog current monitor outputs referenced to GND. Each channel uses an internal 0.8V precision enable threshold with 35mV hysteresis and monitors load current via 100µA/A scaled output current.

It integrates dual 75mΩ (typ) N-channel MOSFET switches with automatic inrush control (1A for 10ms), short-circuit detection (OUT < 1.2V within 300µs), overtemperature protection, and dual-stage overcurrent sensing: a filtered primary comparator (1.2V IMON threshold, ±2.5% accuracy) and unfiltered secondary comparator (2.4V IMON threshold, 2µs response).

Key Specifications

Pinout & Package

Package: 16-Lead 3mm × 3mm × 0.95mm LQFN with exposed thermal pad (Pin 17 = GND). Optimized for high-voltage clearance and thermal performance in RF and industrial environments.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual electronic circuit breaker applications.

Compared with LTC4249AV-1#PBF, the LTC4249AV-2#PBF enables autonomous recovery in distributed RF systems; compared with LTC4249AV2-2#PBF, it offers identical protection functionality in a smaller footprint-critical for space-constrained 5G radio units.

Availability

LTC4249AV-2#PBF is available at Aetrix Electronics and suitable for 5G mMIMO PA arrays, industrial safety interlocks, and condition monitoring systems requiring stable component supply, long-term lifecycle assurance, and guaranteed traceable sourcing.

Supply support for LTC4249AV-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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving precision instrumentation, communications, and industrial markets.

The LTC4249 belongs to Analog Devices' PowerPath™ and Hot Swap™ product line, designed specifically for robust, high-voltage electronic circuit protection and intelligent power management in RF infrastructure and mission-critical industrial equipment.

FAQ

What fault response mode does the LTC4249AV-2#PBF use?

The LTC4249AV-2#PBF uses auto-retry fault response: after an overcurrent, short-circuit, or overtemperature event, it automatically attempts to re-enable after a 1-second cool-down period when the EN input is toggled. This behavior is defined by the "–2" suffix and distinguishes it from the latch-off "–1" variant. The LTC4249AV-2#PBF does not require external reset circuitry, making it ideal for remote or inaccessible deployments like outdoor 5G base stations.

How is the overcurrent threshold set on the LTC4249AV-2#PBF?

The overcurrent threshold on the LTC4249AV-2#PBF is set by a single resistor (RIMON) connected from IMONx to GND. With a 100µA/A current monitor gain and 1.2V primary OC threshold, RIMON = 1.2V / I_ECB × 10,000 - e.g., 10kΩ for 1.2A. The secondary (fast) OC threshold is always twice the primary value (2.4V). No trimming or calibration is needed; threshold accuracy is ±2.5% over temperature.

Can the LTC4249AV-2#PBF be used with IN2 only, without IN1?

No. The LTC4249AV-2#PBF requires IN1 ≥ 6V to power its internal bias rail; IN2 cannot operate independently. IN1 supplies the LDO that generates INTVCC and powers all internal circuitry. If only a low-voltage rail (e.g., 5V) is available, the datasheet describes a special "5V ONLY" configuration using external biasing - but this is not supported in standard operation and voids specified performance guarantees for the LTC4249AV-2#PBF.

What is the maximum output capacitance supported by the LTC4249AV-2#PBF?

The LTC4249AV-2#PBF supports up to 100µF of capacitance at each OUT pin during the 10ms inrush charging phase. Exceeding this limit risks violating the safe operating area due to excessive energy dissipation during turn-on. For reliable operation, a 1µF or greater bypass capacitor is required at IN1/IN2, and a 0.01µF capacitor must be placed at INTVCC. Layout inductance on IN and OUT paths must remain below 400nH to prevent voltage overshoot during fault clearing.

Does the LTC4249AV-2#PBF provide reverse current protection?

The LTC4249AV-2#PBF does not inherently block reverse current flow from OUT to IN, but reverse current detection and isolation can be implemented by back-to-back connection of ECB channels (e.g., cascading OUT1→IN2). In such configurations, the device's precision enable inputs and current monitors allow coordinated control and fault detection. Reverse current protection is an application-level capability-not a built-in feature-and requires careful PCB layout and external component selection to ensure safe operation.