Analog Devices Inc. LTC4440EMS8E#TRPBF

Overview

LTC4440EMS8E#TRPBF from Analog Devices (formerly Linear Technology) is a high-speed, high-voltage high-side N-channel MOSFET gate driver designed for synchronous full-bridge and phase-modulated converters. It operates with TS voltages up to 80V continuous and withstands 100V transients, delivers 2.4A peak pull-up current and 1.5Ω pull-down impedance, and achieves 10ns rise / 7ns fall times into 1nF load - enabling efficient switching of high-gate-charge MOSFETs in telecom and server power supplies.

For engineers reviewing the LTC4440EMS8E#TRPBF datasheet, LTC4440EMS8E#TRPBF pinout, LTC4440EMS8E#TRPBF application, or LTC4440EMS8E#TRPBF equivalent, key selection criteria include its 80V TS rating, bootstrapped high-side drive architecture, TTL/CMOS-compatible input with 350mV hysteresis, dual UVLO (VCC and BOOST–TS), and thermally enhanced MSOP-8 package with exposed ground pad.

Technical Context

The LTC4440EMS8E#TRPBF employs a level-shifted input stage that accepts ground-referenced TTL/CMOS logic and internally shifts it to the bootstrapped domain (up to 115V above ground), enabling direct control of high-side switches without optocouplers or pulse transformers. Its output stage uses an NPN bipolar pull-up (2.4A peak) and N-channel MOSFET pull-down (1.5Ω typical) to achieve fast, low-impedance transitions critical for minimizing MOSFET switching losses.

It integrates independent undervoltage lockout circuits for both VCC (6.2V falling threshold) and BOOST–TS (6.9V falling threshold), ensuring safe disablement during supply brownouts. The device supports operation across –40°C to 85°C ambient, with thermal performance dependent on soldering the exposed pad to PCB ground (θ_JA = 40°C/W).

Key Specifications

Pinout & Package

Package: 8-lead MSOP (MS8E) with exposed thermal pad (Pin 9), 1mm profile, θ_JA = 40°C/W when exposed pad is soldered to PCB ground.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC4440EMS8E#TRPBF, LTC4444ES6#TRPBF offers superior surge resilience and integrated shoot-through guard but demands tighter supply regulation and lacks pin compatibility; LTC4442EMS8E#TRPBF trades voltage range and protection for lower cost and simpler biasing in sub-40V systems.

Availability

LTC4440EMS8E#TRPBF is available at Aetrix Electronics and suitable for telecom power systems, distributed power architectures, and server power supplies requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.

Supply support for LTC4440EMS8E#TRPBF 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 full product support, documentation, and manufacturing continuity for all Linear ICs including the LTC series.

The LTC4440 belongs to Linear's high-voltage gate driver product line, engineered specifically for isolated DC/DC converters in telecom, enterprise computing, and industrial power systems demanding robustness, speed, and thermal efficiency.

FAQ

What is the maximum continuous TS voltage rating for the LTC4440EMS8E#TRPBF?

The LTC4440EMS8E#TRPBF has a maximum continuous TS voltage rating of 80V, with absolute maximum rating of 100V for transients up to 100ms duration. This allows safe operation in 48V and 54V telecom systems subject to GR-1089-CORE Level 3 surges. Operation beyond 80V continuous violates the device's specified operating conditions and may compromise reliability.

Does the LTC4440EMS8E#TRPBF require an external bootstrap diode?

Yes, the LTC4440EMS8E#TRPBF requires an external bootstrap diode connected between VCC (Pin 1) and BOOST (Pin 6). This diode charges the external BOOST–TS capacitor during the low-side switch conduction period. A Schottky diode with low forward voltage and fast recovery (e.g., MBR0530) is recommended to minimize voltage drop and ensure adequate BOOST rail voltage under heavy load.

How does the LTC4440EMS8E#TRPBF handle undervoltage conditions on the BOOST supply?

The LTC4440EMS8E#TRPBF monitors BOOST–TS with a dedicated UVLO circuit having 6.75V rising and 6.25V falling thresholds. When BOOST–TS falls below 6.25V, the TG output is actively pulled down to TS, disabling the high-side MOSFET. Both VCC and BOOST–TS UVLOs must be satisfied for normal operation; if either fails, the device enters low-current mode drawing ~25µA from VCC and ~86µA from BOOST.

Can the LTC4440EMS8E#TRPBF drive a low-side MOSFET?

Yes, the LTC4440EMS8E#TRPBF can drive a low-side N-channel MOSFET by connecting TS to GND and using TG as the gate output referenced to system ground. In this configuration, BOOST is tied to VCC (via diode and capacitor), and the device retains its 2.4A pull-up / 1.5Ω pull-down capability. However, its primary design intent and characterization are for high-side operation with floating TS.

What is the purpose of the exposed pad (Pin 9) on the LTC4440EMS8E#TRPBF MSOP-8 package?

The exposed pad (Pin 9) on the LTC4440EMS8E#TRPBF is electrically connected to GND and serves as the primary thermal dissipation path. It must be soldered to a PCB ground plane with adequate copper area (≥2500 mm² double-sided 1oz) to achieve the specified θ_JA = 40°C/W. Failure to solder the pad results in significantly higher thermal resistance (>100°C/W), risking thermal shutdown or accelerated parametric drift during sustained 2.4A peak drive.