Analog Devices Inc./Maxim Integrated MAX8744ETJ+

Overview

MAX8744ETJ+ from Maxim Integrated is a dual step-down, synchronous switch-mode power-supply (SMPS) controller for notebook main 5V/3.3V generation, featuring 40/60° interleaved operation, 200kHz/300kHz/500kHz selectable switching frequency, and integrated 5V/100mA LDO with bootstrap capability. It supports quad-output power sequencing in battery-powered systems with 6V–26V input range.

For engineers reviewing the MAX8744ETJ+ datasheet, MAX8744ETJ+ pinout, MAX8744ETJ+ application, or MAX8744ETJ+ equivalent, key selection considerations include its overvoltage-fault protection (exclusive to MAX8744), dual-mode feedback (fixed 3.3V/5V or adjustable 2V–5.5V), interleaved phase shift (144°), and low-noise pulse-skipping modes-critical for notebook thermal and acoustic design constraints.

Technical Context

The MAX8744ETJ+ implements fixed-frequency current-mode control with optimal 40/60° interleaving to minimize input ripple across 6V–26V input, delaying duty-cycle overlap until VIN drops to 8.3V-superior to 180° out-of-phase regulators that degrade below 10V. Its architecture integrates two independent SMPS channels (3.3V and 5V), each with peak-current limiting via resistor or DCR sensing, soft-start/soft-shutdown ramping, and independent enable/power-good signaling.

It embeds three regulation domains: a primary 5V/100mA LDO (with automatic bootstrap to 200mA when SMPS active), an auxiliary linear-regulator driver (DRVA/FBA) supporting external PNP for 12V or down-to-1V outputs, and a precision 2.00V ±0.75% reference (REF). Fault protection includes undervoltage, thermal shutdown (+160°C), and-uniquely for MAX8744-output overvoltage detection (8–14% trip threshold, 10µs propagation).

Key Specifications

Pinout & Package

MAX8744ETJ+ is housed in a 32-pin, 5mm × 5mm thin QFN package with exposed thermal pad (T3255-4), optimized for high-power density and thermal dissipation in space-constrained notebook mainboards.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-output SMPS controller applications.

Compared with MAX8745ETJ+, the MAX8744ETJ+ adds critical overvoltage protection for safety-critical notebook rails; versus RT8205AZSP, it delivers superior flexibility via adjustable outputs, integrated reference, and auxiliary LDO control-justifying its use in premium mobile platforms.

Availability

MAX8744ETJ+ is available at Aetrix Electronics and suitable for notebook computers, Li+-powered embedded systems, and portable industrial devices requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX8744ETJ+ 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

Maxim Integrated (now part of Analog Devices) is a semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for demanding applications.

The MAX8744ETJ+ belongs to Maxim's notebook power-controller product line, designed specifically to replace discrete multi-rail solutions with integrated, sequenced, and protected quad-output power management for space- and thermally-constrained mobile platforms.

FAQ

What distinguishes MAX8744ETJ+ from MAX8745ETJ+?

The MAX8744ETJ+ includes output overvoltage-fault protection (8–14% trip threshold, 10µs propagation), while the MAX8745ETJ+ lacks this feature. All other specifications-including pinout, 40/60° interleaving, dual-mode feedback, and auxiliary LDO driver-are identical. This makes MAX8744ETJ+ the preferred choice for systems where rail overvoltage could damage downstream logic or memory.

How does the 40/60° interleaving in MAX8744ETJ+ improve system performance?

The 40/60° interleaving in MAX8744ETJ+ reduces input capacitor RMS current by ~30% compared to conventional 180° interleaving, delaying duty-cycle overlap until input voltage drops to 8.3V (vs. 10V for 180°). This enables smaller input bulk capacitors, lower EMI, and improved efficiency across the full 6V–26V input range-especially beneficial in compact notebook designs.

Can MAX8744ETJ+ generate voltages other than 3.3V and 5V?

Yes. Using the Dual Mode™ feedback architecture, MAX8744ETJ+ supports adjustable outputs from 2.0V to 5.5V via external resistor dividers on FB3/FB5 pins (regulated to 2.00V reference). Additionally, the auxiliary LDO driver (DRVA/FBA) enables external PNP-based generation of 12V or any voltage down to 1V-providing true quad-output flexibility beyond fixed rails.

What is the role of the REF pin on MAX8744ETJ+ and how should it be used?

The REF pin on MAX8744ETJ+ provides a precision 2.00V ±0.75% reference output used for feedback thresholding in adjustable mode and scaling the current-limit threshold (ILIM). It must be bypassed to analog ground with ≥0.1µF ceramic capacitance. Loading REF beyond 50µA degrades accuracy per the load-regulation error spec (±10mV), so external circuits should minimize current draw.

How does MAX8744ETJ+ manage thermal performance in high-density notebook layouts?

MAX8744ETJ+ uses a 32-pin 5mm × 5mm thin QFN package with an exposed thermal pad soldered directly to the PCB ground plane. Combined with its high-efficiency interleaved architecture and 8µA shutdown current, this design minimizes junction temperature rise. Thermal shutdown activates at +160°C with 15°C hysteresis, providing fail-safe protection during sustained overload or inadequate heatsinking.