Analog Devices Inc./Maxim Integrated MAX8866SEUA+

Overview

MAX8866SEUA+ from Maxim Integrated is a dual, low-dropout linear regulator IC delivering two independent 2.84V fixed or adjustable (1.25V–5.5V) outputs, each rated for up to 100mA load current. It operates from +2.5V to +5.5V input, features 55mV dropout at 50mA, 105µA no-load supply current, and integrated auto-discharge on shutdown - designed for space-constrained, battery-powered portable systems including cellular phones and modems.

For engineers reviewing the MAX8866SEUA+ datasheet, MAX8866SEUA+ pinout, MAX8866SEUA+ application, or MAX8866SEUA+ equivalent, key selection criteria include dual-output independence, active output discharge during shutdown, low-noise (350µVRMS) regulation, thermal/short-circuit protection, and µMAX-8 package compatibility with high-density PCB layouts.

Technical Context

The MAX8866SEUA+ integrates two independent P-channel MOSFET-based LDO regulators sharing a 1.25V bandgap reference and thermal sensor but featuring separate error amplifiers, MOSFET drivers, and shutdown logic. Each regulator supports Dual Mode™ operation: preset 2.84V output when SET pins are grounded, or adjustable output via external resistor dividers tied to SET1/SET2.

Unlike PNP-based regulators, its 1.1Ω typical R_DS(ON) PMOS pass transistors eliminate base-drive current, enabling stable 145µA operating supply current across dropout, light-load, and full-load conditions. The MAX8866 variant adds auto-discharge circuitry that actively pulls OUT1/OUT2 to GND upon SHDN assertion - a feature absent in the MAX8865.

Key Specifications

Pinout & Package

MAX8866SEUA+ is housed in an 8-pin µMAX package (3.05mm × 3.05mm × 0.8mm), optimized for high thermal performance (θ_JA = 244°C/W) and dense PCB layouts. Exposed pad soldering to ground plane recommended for enhanced heat dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-LDO regulator applications.

Compared with MAX8865SEUA+, the MAX8866SEUA+ adds essential auto-discharge for robust power sequencing, while TSM1024IDT fails to replicate dual-output independence, low-noise performance, or protection features - making MAX8866SEUA+ the optimal choice for compact, reliable dual-rail portable power.

Availability

MAX8866SEUA+ is available at Aetrix Electronics and suitable for cellular telephones, cordless telephones, and hand-held instruments requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for MAX8866SEUA+ 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 U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, communications, and consumer applications.

The MAX8865/MAX8866 product line was engineered specifically for ultra-low-power, dual-rail battery-powered portable electronics - emphasizing minimal quiescent current, small footprint, and integrated protection features without sacrificing output accuracy or noise performance.

FAQ

What is the fixed output voltage of the MAX8866SEUA+?

The MAX8866SEUA+ delivers two independent fixed outputs of 2.84V each, achieved by grounding the SET1 and SET2 pins. This voltage is factory-trimmed to ±3% accuracy over the full operating temperature range (-40°C to +85°C) and does not require external feedback components. The "S" suffix in MAX8866SEUA+ explicitly denotes the 2.84V preset version, distinguishing it from the "T" (3.15V) and "R" (2.80V) variants.

Does the MAX8866SEUA+ support adjustable output voltages?

Yes, the MAX8866SEUA+ supports adjustable outputs from 1.25V to 5.5V per channel using external resistor dividers connected to SET1 and SET2. When SETx is tied to an external voltage divider instead of GND, the device enters Dual Mode™ adjustable operation. The output follows V_OUT = 1.25V × (1 + R1/R2), with R2 typically selected as 100kΩ to optimize accuracy and PSRR. This flexibility allows one MAX8866SEUA+ design to serve multiple voltage requirements without changing the IC.

How does the auto-discharge function work on the MAX8866SEUA+?

The MAX8866SEUA+ features dedicated auto-discharge circuitry that actively pulls OUT1 or OUT2 to GND within 1ms when the corresponding SHDN1 or SHDN2 pin is driven low. This is a key differentiator from the MAX8865SEUA+, which lacks this function. The discharge path is internal and does not require external components, ensuring rapid, controlled voltage collapse essential for power sequencing, system reset integrity, and preventing unintended wake-up in deep-sleep states.

What protection features are integrated into the MAX8866SEUA+?

The MAX8866SEUA+ integrates five critical protection functions: (1) thermal shutdown triggered at +170°C junction temperature with 20°C hysteresis; (2) output current limiting (~220mA typical) per channel; (3) reverse battery protection limiting reverse current to <1mA; (4) short-circuit protection enabling indefinite output shorting; and (5) safe shutdown behavior with auto-discharge. These features eliminate the need for external protection circuitry in battery-powered designs, improving reliability and reducing BOM count.

Can the MAX8866SEUA+ operate from a single alkaline cell?

Yes, the MAX8866SEUA+ supports input voltages as low as +2.5V, making it compatible with a single alkaline cell (nominal 1.5V, fresh up to 1.65V, end-of-life ~0.9V per cell - but two cells in series provide 1.8V–3.3V). For true single-cell operation, two alkaline cells (2.0V–3.3V) or a single Li-ion cell (3.0V–4.2V) are appropriate. Its 55mV dropout at 50mA ensures regulation remains active until VIN drops to ~2.895V for a 2.84V output - maximizing usable battery energy in portable equipment.