Analog Devices Inc. LTC4444HMS8E-5#TRPBF

Overview

LTC4444HMS8E-5#TRPBF from Analog Devices (formerly Linear Technology) is a high-frequency, high-voltage synchronous N-channel MOSFET gate driver IC designed for buck and buck-boost DC/DC converters. It drives both high-side and low-side N-MOSFETs with 1.4A peak top-gate pull-up, 1.75A peak bottom-gate pull-up, and adaptive shoot-through protection. It operates with VCC from 4.5V to 13.5V and supports bootstrapped high-side supply up to 114V above ground - enabling use in automotive power supplies and high-density telecom modules.

For engineers reviewing the LTC4444HMS8E-5#TRPBF datasheet, LTC4444HMS8E-5#TRPBF pinout, LTC4444HMS8E-5#TRPBF application, or LTC4444HMS8E-5#TRPBF equivalent, key selection criteria include its 150°C max junction temperature rating, 3ns–8ns switching times into 1nF loads, undervoltage lockout thresholds (3.55V rising / 3.20V falling), thermally enhanced MSOP-8 package with exposed pad, and dual independent input logic with internal level-shifting.

Technical Context

The LTC4444HMS8E-5#TRPBF implements a dual-output CMOS-input gate driver with separate TINP/BINP control signals, internal high-side level shifter referenced to TS, and adaptive shoot-through protection that monitors TS voltage transitions to sequence BG and TG activation. Its output stage uses bipolar pull-up transistors and N-MOSFET pull-down devices, delivering 0.75Ω low-side and 1.5Ω high-side pull-down resistance.

It integrates undervoltage lockout on VCC (3.55V/3.20V hysteresis), consumes only 320–520μA quiescent current, and features input thresholds (VIH = 2.75V, VIL = 2.30V) with 450mV hysteresis - ensuring noise immunity in high-dV/dt environments. The device is rated for –40°C to +150°C operating junction temperature and requires soldering of the exposed GND pad for θJA = 40°C/W thermal performance.

Key Specifications

Pinout & Package

Package: 8-lead plastic MSOP (MS8E) with exposed GND pad (Pin 9), rated for –40°C to +150°C operation. Exposed pad must be soldered to PCB ground for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage synchronous N-MOSFET driver applications.

Compared with LTC4446 and LTC4444IMS8E-5#TRPBF, the LTC4444HMS8E-5#TRPBF uniquely combines adaptive shoot-through protection, 150°C junction rating, and optimized 1.4A/1.75A drive strength - making it the only option qualified for high-reliability, high-temperature synchronous buck designs without external timing or thermal derating.

Availability

LTC4444HMS8E-5#TRPBF is available at Aetrix Electronics and suitable for automotive power supplies, telecommunication systems, and high-density power modules requiring stable component supply, long-term lifecycle support, and guaranteed H-grade thermal performance.

Supply support for LTC4444HMS8E-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 full product continuity, technical support, and manufacturing for all Linear power ICs including the LTC4444 family.

The LTC4444 series was designed specifically for high-efficiency, high-voltage synchronous DC/DC converters - emphasizing robust gate drive, adaptive timing control, and thermal resilience in space-constrained power systems.

FAQ

What is the maximum allowable voltage on the BOOST pin relative to TS for the LTC4444HMS8E-5#TRPBF?

The BOOST pin of the LTC4444HMS8E-5#TRPBF supports up to 114V above TS, enabling high-side operation in 100V-input buck converters. This rating is absolute - exceeding 114V risks permanent damage. The device's internal level shifter and adaptive shoot-through protection rely on this voltage headroom to maintain reliable high-side gate drive without external components.

Does the LTC4444HMS8E-5#TRPBF require external bootstrap diodes, and what specifications are critical?

Yes, the LTC4444HMS8E-5#TRPBF requires an external bootstrap diode between VCC (Pin 3) and BOOST (Pin 6). A Schottky diode with ≤0.4V forward voltage and ≥100mA average current rating is recommended. Low reverse leakage (<1μA) is critical to minimize BOOST voltage droop during high-duty-cycle operation, which directly impacts high-side drive strength and timing accuracy.

How does adaptive shoot-through protection work in the LTC4444HMS8E-5#TRPBF, and how is it different from fixed dead-time schemes?

The LTC4444HMS8E-5#TRPBF monitors the TS pin voltage to dynamically sequence BG and TG activation. If TS remains high after TINP turns off, BG is delayed by 150ns before turning on - eliminating cross-conduction without fixed dead-time penalties. Unlike fixed schemes, this adapts to MOSFET switching speed, layout parasitics, and temperature drift, improving efficiency across varying load and input conditions.

Can the LTC4444HMS8E-5#TRPBF drive both high-side and low-side MOSFETs in a half-bridge configuration with a single PWM signal?

No - the LTC4444HMS8E-5#TRPBF requires two independent input signals: TINP for TG (high-side) and BINP for BG (low-side). It does not include internal complementary logic or PWM-to-half-bridge translation. Using a single PWM signal would require external inverters or a controller with dedicated high/low outputs, as the device's adaptive shoot-through protection depends on asynchronous input control.

What is the purpose of the exposed pad (Pin 9) on the LTC4444HMS8E-5#TRPBF, and what happens if it is not soldered?

The exposed pad (Pin 9) on the LTC4444HMS8E-5#TRPBF serves as the primary thermal and electrical ground connection. If unsoldered, thermal resistance increases dramatically - from the specified 40°C/W to >100°C/W - causing junction temperature to exceed 150°C under moderate load, triggering thermal shutdown and risking long-term reliability failure. Soldering to a 2500mm² double-sided copper plane is mandatory for rated operation.