Analog Devices Inc. LTC4440AIMS8E-5#PBF

Overview

LTC4440AIMS8E-5#PBF from Analog Devices (formerly Linear Technology) is a high-frequency, high-voltage, high-side N-channel MOSFET gate driver optimized for synchronous phase-modulated full-bridge converters. It operates with VIN up to 80V, withstands 100V transients, delivers 1.1A peak pull-up current and 1.85Ω pull-down impedance at 6V BOOST–TS, and drives 1nF loads with 10ns rise/7ns fall times - enabling efficient switching in telecom and server power supplies.

For engineers reviewing the LTC4440AIMS8E-5#PBF datasheet, LTC4440AIMS8E-5#PBF pinout, LTC4440AIMS8E-5#PBF application, or LTC4440AIMS8E-5#PBF equivalent, key selection criteria include bootstrapped high-side drive capability, supply-independent TTL/CMOS input thresholds with 350mV hysteresis, undervoltage lockout (3.04V falling), thermal performance in the MSOP-8E package, and compatibility with standard-threshold MOSFETs in isolated DC/DC topologies.

Technical Context

The LTC4440AIMS8E-5#PBF integrates a level-shifted input stage that accepts ground-referenced logic signals and translates them to the floating BOOST–TS domain, enabling direct control of high-side FETs with source voltages up to 80V. Its output stage combines an NPN pull-up transistor (1.1A peak) and an NMOS pull-down device (1.85Ω typical R_DS) to minimize switching losses in high-C_iss power MOSFETs.

It features internal undervoltage lockout disabling TG when VCC falls below 3.04V, and supports robust operation under transient conditions (100V/100ms on TS). The driver's 350mV input hysteresis and low input bias current (<±2µA) ensure noise immunity in high-dv/dt environments typical of full-bridge and phase-shifted converter applications.

Key Specifications

Pinout & Package

The LTC4440AIMS8E-5#PBF is housed in an 8-lead plastic MSOP package with exposed pad (Pin 9 = GND), requiring soldering to PCB ground for θ_JA = 40°C/W thermal performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-side gate driver applications.

Compared with LTC4444-5 and LM5109B, the LTC4440AIMS8E-5#PBF offers optimal balance of transient robustness (100V/100ms), wide VCC range (4V–15V), and proven noise immunity - making it the preferred choice for industrial and telecom full-bridge converters where reliability under fault conditions is critical.

Availability

LTC4440AIMS8E-5#PBF is available at Aetrix Electronics and suitable for telecom power supplies, server power modules, and industrial motor drives requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for LTC4440AIMS8E-5#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 acquired Linear Technology in 2017 and maintains its high-performance analog and power management portfolio. Linear Technology was renowned for precision analog ICs and robust power solutions targeting demanding applications.

The LTC4440AIMS8E-5#PBF belongs to Linear's high-voltage gate driver product line, engineered specifically for isolated DC/DC converters, full-bridge topologies, and high-reliability power systems where transient immunity, thermal performance, and precise timing control are essential.

FAQ

What is the maximum continuous input voltage rating for the LTC4440AIMS8E-5#PBF?

The LTC4440AIMS8E-5#PBF supports continuous operation with TS voltage up to 80V. Its absolute maximum TS rating is 100V for 100ms transients, allowing safe use in 48V and 60V telecom and industrial bus systems with expected overvoltage events. This rating is verified per Linear Technology's Absolute Maximum Ratings table and applies to the TS pin referenced to system ground.

Does the LTC4440AIMS8E-5#PBF require an external bootstrap diode?

Yes, the LTC4440AIMS8E-5#PBF requires an external bootstrap diode connected between VCC (Pin 3) and BOOST (Pin 6) to charge the bootstrap capacitor during low-side conduction. The diode's forward voltage drop affects the achievable BOOST–TS voltage swing, and a Schottky diode (e.g., MBR0530) is recommended to minimize voltage loss and improve high-side drive strength in the LTC4440AIMS8E-5#PBF.

What is the purpose of the exposed pad (Pin 9) on the LTC4440AIMS8E-5#PBF MSOP-8E package?

The exposed pad (Pin 9) on the LTC4440AIMS8E-5#PBF is electrically connected to GND and must be soldered to the PCB ground plane to achieve the specified thermal resistance of 40°C/W. Failure to solder this pad results in significantly degraded thermal performance - potentially exceeding junction temperature limits under sustained load - and is explicitly required in Linear's Package Description and Applications Information sections for the LTC4440AIMS8E-5#PBF.

Can the LTC4440AIMS8E-5#PBF drive both high-side and low-side N-channel MOSFETs?

Yes, the LTC4440AIMS8E-5#PBF can drive low-side N-channel MOSFETs by connecting TS (Pin 8) to system ground, effectively converting it to a ground-referenced driver. Its 1.1A peak pull-up and 1.85Ω pull-down remain fully functional in this configuration, and the input thresholds and UVLO operate identically. This dual-role capability is confirmed in the Applications Information section of the LTC4440AIMS8E-5#PBF datasheet.

What is the minimum VCC voltage required for the LTC4440AIMS8E-5#PBF to enable gate drive output?

The LTC4440AIMS8E-5#PBF enables gate drive output only when VCC rises above the undervoltage lockout (UVLO) threshold of 3.20V. Below 3.04V, the output TG is actively pulled low to TS. This 160mV hysteresis prevents oscillation during power-up or brown-out conditions and is a defined specification in the Electrical Characteristics table for the LTC4440AIMS8E-5#PBF.