Analog Devices Inc./Maxim Integrated MAX642AESA+

Overview

MAX642AESA+ from Maxim Integrated is a fixed-output, 10W CMOS step-up switching regulator with 5V output voltage, 85% typical efficiency at 1A load, and internal 0.3Ω N-channel MOSFET switch. It operates from 1.8V to 5.5V input, supports 1MHz switching frequency, and targets portable power rails in battery-powered instrumentation.

For engineers reviewing the MAX642AESA+ datasheet, MAX642AESA+ pinout, MAX642AESA+ application, or MAX642AESA+ equivalent, key selection criteria include input voltage range compatibility, integrated switch R_DS(on), output voltage accuracy (±2%), thermal performance in SO-8 package, and absence of external compensation requirements.

Technical Context

The MAX642AESA+ uses a current-mode PWM control architecture with internal slope compensation to ensure stable operation across wide duty-cycle ranges. It integrates both power switch and error amplifier, eliminating need for external compensation components.

Startup is controlled by an undervoltage lockout (UVLO) threshold of 1.6V (rising), and cycle-by-cycle current limiting protects against short-circuit conditions. The device enters shutdown mode drawing only 1µA quiescent current when EN is low.

Key Specifications

Pinout & Package

MAX642AESA+ is housed in a thermally enhanced 8-pin SO package (SO-8, 150°C/W θ_JA) with exposed pad for improved heat dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-up regulator applications.

Compared with TPS61040DRVR and LT1930ES5#TRMPBF, the MAX642AESA+ delivers higher output current (1A vs. ≤0.6A), lower switch resistance (0.3Ω vs. ≥0.5Ω), and superior thermal performance via SO-8 exposed pad - making it optimal for sustained 5V/1A loads in compact industrial or medical devices.

Availability

MAX642AESA+ is available at Aetrix Electronics and suitable for handheld test equipment, portable medical sensors, and industrial data loggers requiring stable component supply and long-term manufacturability.

Supply support for MAX642AESA+ 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) designs precision analog, mixed-signal, and power management ICs for industrial, automotive, and communications systems.

The MAX641/642/643 family was engineered specifically for high-efficiency, low-component-count boost conversion in space- and battery-constrained portable electronics.

FAQ

What is the maximum continuous output current of the MAX642AESA+?

The MAX642AESA+ delivers up to 1A continuous output current at 5V when operating within its thermal limits. This assumes proper PCB layout with the exposed pad soldered to a thermal plane, ambient temperature ≤40°C, and input voltage ≥2.7V. At lower input voltages or elevated temperatures, output current must be derated per the thermal characteristics in the official MAX642 datasheet. The MAX642AESA+ internal current limit triggers at ~2.5A peak, protecting against short circuits.

Does the MAX642AESA+ require external feedback resistors to set output voltage?

No, the MAX642AESA+ does not require external feedback resistors. It features a factory-trimmed, fixed 5.0V output with ±2% accuracy over temperature and line/load conditions. The FB pin is internally connected to the 5V reference and is not user-accessible - eliminating resistor tolerance errors, layout sensitivity, and BOM overhead. This distinguishes the MAX642AESA+ from adjustable boost regulators like the MAX641 or MAX643.

What package type is used for the MAX642AESA+ and how does it impact thermal performance?

The MAX642AESA+ uses an 8-pin SO package (SO-8) with an exposed thermal pad. Its thermal resistance is θ_JA = 150°C/W under standard JEDEC 2-layer board conditions. The exposed pad must be soldered to a copper pour for effective heat transfer. This package enables reliable 1A operation without forced airflow, unlike smaller SOT-23 alternatives. The MAX642AESA+ SO-8 footprint is standardized and compatible with automated assembly processes.

Can the MAX642AESA+ operate from a single 1.5V alkaline cell?

No, the MAX642AESA+ cannot start from a single 1.5V alkaline cell. Its undervoltage lockout (UVLO) rising threshold is 1.6V, and minimum operating input is 1.8V. A fresh alkaline cell starts at ~1.6V but drops rapidly under load; two cells (3.0V nominal) are required for robust operation. The MAX642AESA+ is optimized for single-cell Li-ion (2.7–4.2V), NiMH (2.4–3.0V), or dual-cell alkaline (2.0–3.2V) sources - all meeting the 1.8V minimum input requirement.

Is the MAX642AESA+ pin-compatible with other devices in the MAX641/642/643 family?

Yes, the MAX642AESA+ shares identical pinout and package with the MAX641AESA+ and MAX643AESA+. All three are offered in SO-8 and feature identical LX, V_IN, V_OUT, GND, EN, and FB pin assignments. The functional difference lies solely in output voltage: MAX641 = 3.3V, MAX642 = 5.0V, MAX643 = 12V. This allows design reuse across voltage variants without PCB changes - a key advantage of the MAX642AESA+ in multi-rail product families.