Analog Devices Inc. LTC4444EMS8E-5#TRPBF

Overview

LTC4444EMS8E-5#TRPBF from Analog Devices (formerly Linear Technology) is a high-frequency, high-voltage synchronous N-channel MOSFET gate driver for buck and buck-boost DC/DC converters. It drives both high-side (TG) and low-side (BG) N-MOSFETs with 1.4A peak top-gate pull-up, 1.75A peak bottom-gate pull-up, adaptive shoot-through protection, and operates with VCC from 4.5V to 13.5V and bootstrap voltage up to 114V above TS. It enables high-efficiency power stages in automotive and telecom power supplies.

For engineers reviewing the LTC4444EMS8E-5#TRPBF datasheet, LTC4444EMS8E-5#TRPBF pinout, LTC4444EMS8E-5#TRPBF application, or LTC4444EMS8E-5#TRPBF equivalent, key selection criteria include bootstrap voltage tolerance (up to 114V), dual independent inputs with internal level-shifting, undervoltage lockout thresholds (3.55V falling), thermal performance in MS8E package, and adaptive shoot-through prevention timing behavior.

Technical Context

The LTC4444EMS8E-5#TRPBF integrates a high-side level shifter that references TINP to GND while driving TG relative to TS and BOOST, enabling operation with TS up to 100V. Its adaptive shoot-through protection monitors TS voltage transitions and enforces dead-time between BG turn-off and TG turn-on - delaying TG activation by up to 150ns if TS remains high after TINP assertion.

Internally, it uses bipolar NPN pull-up transistors (Q1/Q2) and N-channel MOSFET pull-down devices (M1/M2), delivering low R_DS(ON) of 1.5Ω (TG) and 0.75Ω (BG) at junction temperatures ≤125°C. Input buffers feature CMOS-compatible thresholds (VIH = 2.75V, VIL = 2.3V, 450mV hysteresis) independent of VCC variation, ensuring noise-immune digital control in high-dV/dt environments.

Key Specifications

Pinout & Package

Package: 8-lead plastic MSOP (MS8E) with thermally enhanced exposed pad (Pin 9 = GND). Requires soldering of exposed pad to PCB ground for thermal compliance (θ_JA = 40°C/W); unsoldered pad degrades thermal resistance significantly.

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 LTC4440-5, the LTC4444EMS8E-5#TRPBF uniquely combines dual independent inputs, adaptive shoot-through protection, and 114V BOOST–TS rating - making it optimal for high-reliability synchronous buck converters where internal dead-time management and wide input voltage range are essential.

Availability

LTC4444EMS8E-5#TRPBF is available at Aetrix Electronics and suitable for automotive power supplies, telecommunication systems, and high-density power modules requiring stable component supply, extended temperature operation (–40°C to 125°C), and long-term industrial lifecycle support.

Supply support for LTC4444EMS8E-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, Inc. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors.

The LTC4444EMS8E-5#TRPBF belongs to Linear's high-voltage gate driver product line, engineered specifically for efficient, robust control of N-channel MOSFETs in demanding DC/DC conversion topologies including buck, buck-boost, and active clamp forward converters.

FAQ

What is the maximum allowable voltage on the BOOST pin relative to TS for the LTC4444EMS8E-5#TRPBF?

The BOOST pin of the LTC4444EMS8E-5#TRPBF supports a maximum voltage of 114V relative to TS (BOOST – TS). This rating enables reliable operation in high-input-voltage applications such as 48V telecom systems and automotive 42V architectures, where the high-side switch node may swing near 100V. Exceeding this differential risks permanent damage per Absolute Maximum Ratings.

Does the LTC4444EMS8E-5#TRPBF require external bootstrap diodes, and what are the key selection criteria?

Yes, the LTC4444EMS8E-5#TRPBF requires an external bootstrap diode connected between VCC (Pin 3) and BOOST (Pin 6). Key selection criteria include low forward voltage (<0.5V), fast recovery (<30ns), and sufficient current rating (>10mA average). Schottky diodes such as Diodes Inc. B1100-13-F are commonly used. The diode must withstand reverse voltage up to VCC + VIN (max 100V + 13.5V).

How does adaptive shoot-through protection work in the LTC4444EMS8E-5#TRPBF, and how does it differ from fixed dead-time schemes?

The LTC4444EMS8E-5#TRPBF implements adaptive shoot-through protection by monitoring the TS pin voltage. If TS remains high after TINP asserts, TG activation is delayed up to 150ns until TS falls - eliminating fixed dead-time overhead. Unlike fixed schemes, this adapts to MOSFET switching speed and layout parasitics, maximizing duty cycle while guaranteeing zero shoot-through. This behavior is intrinsic to the LTC4444EMS8E-5#TRPBF and requires no external components.

What is the recommended PCB layout practice for the exposed thermal pad (Pin 9) of the LTC4444EMS8E-5#TRPBF?

The exposed pad (Pin 9) of the LTC4444EMS8E-5#TRPBF must be soldered to a solid, low-impedance PCB ground plane covering ≥2500 mm² on double-sided 1 oz copper. Thermal vias (≥6×0.3mm diameter) should connect top and bottom ground planes. Failure to solder the pad increases θ_JA beyond 40°C/W, risking thermal shutdown at full drive current. This requirement is explicitly defined in the LTC4444EMS8E-5#TRPBF datasheet.

Can the LTC4444EMS8E-5#TRPBF drive GaN HEMTs, and what design considerations apply?

The LTC4444EMS8E-5#TRPBF can drive enhancement-mode GaN HEMTs provided their gate threshold (typically 1.2–1.8V) and max gate-source voltage (±20V) are compatible with the LTC4444EMS8E-5#TRPBF's output swing (VCC to GND for BG; BOOST to TS for TG) and 0.7V V_BE-limited high-side output. Critical considerations include minimizing gate loop inductance, using RC snubbers, and verifying that 3ns BG fall time does not cause excessive dV/dt-induced turn-on in cascode GaN devices.