Analog Devices Inc. LTC4440AHMS8E-5#TRPBF

Overview

LTC4440AHMS8E-5#TRPBF from Analog Devices (formerly Linear Technology) is a high-frequency, high-voltage, high-side N-channel MOSFET gate driver optimized for full-bridge and phase-modulated 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 achieves 10ns rise / 7ns fall times driving 1nF loads - enabling low-loss switching in telecom and server power supplies.

For engineers reviewing the LTC4440AHMS8E-5#TRPBF datasheet, LTC4440AHMS8E-5#TRPBF pinout, LTC4440AHMS8E-5#TRPBF application, or LTC4440AHMS8E-5#TRPBF equivalent, key selection criteria include its 150°C junction-rated MS8E package, supply-independent TTL/CMOS input thresholds with 350mV hysteresis, undervoltage lockout (3.04V falling), and bootstrapped level-shifting for gate drive up to 95V above TS.

Technical Context

The LTC4440AHMS8E-5#TRPBF uses a bipolar-NMOS hybrid output stage: an NPN transistor (Q1) for high-current pull-up and an NMOS (N1) for low-impedance pull-down. Its input buffer features internal regulation to maintain VIH = 1.6V and VIL = 1.25V across VCC variations, with nonoverlapping predriver logic preventing shoot-through during transitions.

It supports bootstrapped operation where BOOST swings from VCC – V_D to VIN + VCC – V_D, enabling high-side drive without isolated supplies. The device includes undervoltage lockout that forces TG low when VCC drops below 3.04V, and requires soldering of the exposed thermal pad (Pin 9) to PCB ground for θ_JA = 40°C/W.

Key Specifications

Pinout & Package

The LTC4440AHMS8E-5#TRPBF is housed in an 8-lead plastic MSOP package (MS8E) with exposed thermal pad (Pin 9) that must be soldered to PCB ground for thermal performance. Package dimensions: 3.00mm × 3.00mm × 0.86mm, pitch 0.65mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC4444-5, the LTC4440AHMS8E-5#TRPBF trades shoot-through protection for tighter timing control and wider VIN tolerance; versus LM5109B, it offers superior transient resilience and lower pull-down impedance critical for high-dV/dt full-bridge operation.

Availability

LTC4440AHMS8E-5#TRPBF is available at Aetrix Electronics and suitable for telecom power supplies, server power modules, and industrial motor drives requiring stable component supply, extended temperature operation, and high-voltage transient resilience.

Supply support for LTC4440AHMS8E-5#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 its high-performance analog and power IC portfolio with rigorous qualification and long-term support.

The LTC4440A family was designed specifically for high-efficiency, high-density isolated DC/DC converters - targeting full-bridge, phase-shifted, and resonant topologies in telecom, computing, and industrial power systems.

FAQ

What is the maximum allowable voltage on the TS pin of the LTC4440AHMS8E-5#TRPBF?

The TS pin of the LTC4440AHMS8E-5#TRPBF supports up to 80V continuously and withstands 100V for 100ms. This rating enables use in high-input-voltage full-bridge converters where the high-side source node floats near VIN. Exceeding 100V even briefly risks permanent damage, and proper PCB layout with minimized parasitic inductance is essential to avoid voltage overshoot during fast switching transitions in the LTC4440AHMS8E-5#TRPBF.

Does the LTC4440AHMS8E-5#TRPBF require an external bootstrap diode?

Yes, the LTC4440AHMS8E-5#TRPBF requires an external bootstrap diode connected between VCC (Pin 3) and BOOST (Pin 6). This diode charges the external bootstrap capacitor during the low-side conduction phase, enabling the high-side driver stage to operate when TS rises above ground. A Schottky diode with low forward voltage and fast recovery (e.g., 1N5819) is recommended to minimize voltage drop and ensure reliable BOOST rail establishment in the LTC4440AHMS8E-5#TRPBF.

How does the undervoltage lockout (UVLO) function in the LTC4440AHMS8E-5#TRPBF?

The LTC4440AHMS8E-5#TRPBF disables its TG output when VCC falls below 3.04V (falling threshold), pulling TG low to TS. This prevents partial turn-on of the driven MOSFET, which could cause excessive conduction loss or shoot-through. The UVLO has 160mV hysteresis (rising threshold = 3.20V), ensuring clean re-enablement after recovery. This behavior is fully specified over the –40°C to 150°C junction range and applies directly to the LTC4440AHMS8E-5#TRPBF.

Can the LTC4440AHMS8E-5#TRPBF drive both high-side and low-side N-MOSFETs?

Yes, the LTC4440AHMS8E-5#TRPBF can drive low-side N-MOSFETs by connecting TS to ground - converting it into a ground-referenced driver. In this configuration, BOOST becomes the gate drive supply referenced to GND, and TG swings from GND to BOOST. The device's 1.1A pull-up and 1.85Ω pull-down remain effective, and input thresholds stay supply-independent. This dual-mode capability is explicitly supported and characterized in the LTC4440AHMS8E-5#TRPBF datasheet.

What is the purpose of the exposed pad (Pin 9) on the LTC4440AHMS8E-5#TRPBF MS8E package?

The exposed pad (Pin 9) on the LTC4440AHMS8E-5#TRPBF is electrically connected to GND and serves as the primary thermal path. When soldered to a minimum 2500 mm² double-sided 1 oz copper ground plane, it achieves θ_JA = 40°C/W. Failure to solder this pad results in significantly degraded thermal performance (>100°C/W), risking junction overheating and premature failure under sustained load. This requirement is mandatory for reliable operation of the LTC4440AHMS8E-5#TRPBF at its rated 150°C junction temperature.