Analog Devices Inc./Maxim Integrated MAX8866REUA+

Overview

MAX8866REUA+ from Maxim Integrated is a dual, low-dropout linear regulator IC delivering two independent 2.80V outputs at up to 100mA each, operating from +2.5V to +5.5V input. It features PMOS pass transistors (1.1Ω typical R_DS(ON)), 55mV dropout at 50mA, 145µA operating supply current, and auto-discharge functionality on shutdown - designed for space-constrained, battery-powered portable electronics including cellular phones and PCMCIA cards.

For engineers reviewing the MAX8866REUA+ datasheet, MAX8866REUA+ pinout, MAX8866REUA+ application, or MAX8866REUA+ equivalent, key selection criteria include fixed 2.80V dual-output capability, µMAX-8 package footprint, independent active-low shutdown with discharge, thermal/short-circuit/reverse-battery protection, and compatibility with ceramic output capacitors ≥1µF.

Technical Context

The MAX8866REUA+ integrates two independent LDO regulators sharing a 1.25V bandgap reference and thermal sensor, each with its own error amplifier, MOSFET driver, P-channel pass transistor, Dual Mode™ comparator, and current limiter. Its preset mode fixes both outputs to 2.80V via internal feedback when SET1/SET2 are grounded.

Unlike PNP-based regulators, it eliminates base-drive current loss and maintains 145µA quiescent current across dropout, light-load, and full-load conditions. The MAX8866 variant adds active auto-discharge of OUT1/OUT2 to GND during SHDN assertion - a feature absent in the MAX8865 family.

Key Specifications

Pinout & Package

Package: 8-pin µMAX (3.0mm × 3.0mm × 0.8mm, 0.65mm pitch), thermally enhanced with exposed pad (GND-connected) for improved dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX8866REUA+, MAX8865REUA+ omits auto-discharge but matches all electrical and mechanical specs, while TSM1024IDT trades compact dual-2.80V capability for quad-rail flexibility in larger packages - making MAX8866REUA+ optimal for space-constrained 2.8V dual-rail designs requiring active shutdown discharge.

Availability

MAX8866REUA+ is available at Aetrix Electronics and suitable for cellular telephones, cordless telephones, and PCMCIA cards requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for MAX8866REUA+ 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 high-performance analog and mixed-signal ICs for power management, sensing, and communications applications.

The MAX886x series targets battery-powered portable equipment, delivering dual low-quiescent-current LDOs with integrated protection and flexible output configuration in miniature packages.

FAQ

What output voltage does the MAX8866REUA+ deliver?

The MAX8866REUA+ delivers two independent, factory-trimmed 2.80V outputs (±3% over temperature and line/load). This value is fixed by grounding both SET1 and SET2 pins - no external resistors are needed. The "R" suffix explicitly denotes the 2.80V variant, distinguishing it from the 2.84V ("S") and 3.15V ("T") versions in the same family.

Does the MAX8866REUA+ support adjustable output voltages?

Yes, the MAX8866REUA+ supports adjustable outputs from 1.25V to 5.5V per channel using external resistor dividers on SET1 and SET2. However, this requires disconnecting those pins from GND and connecting them to custom feedback networks. For the standard 2.80V operation, SET1 and SET2 must remain grounded to engage the internal trimmed divider.

What is the purpose of the auto-discharge function in the MAX8866REUA+?

The auto-discharge function in the MAX8866REUA+ actively pulls OUT1 or OUT2 to GND within 1ms when the corresponding SHDN1 or SHDN2 pin is driven low. This prevents residual voltage from floating or back-driving other circuitry during shutdown - a critical feature for systems requiring clean power sequencing and isolation, such as RF modules or memory interfaces.

How does the MAX8866REUA+ handle thermal overload?

The MAX8866REUA+ incorporates thermal shutdown that trips at +170°C junction temperature, disabling both regulators until the die cools by ~20°C. This hysteresis prevents oscillation during sustained overload. Unlike some LDOs, it does not latch off - instead entering pulsed operation to limit average power dissipation while maintaining basic protection.

Can the MAX8866REUA+ operate with ceramic output capacitors?

Yes, the MAX8866REUA+ is fully stable with ≥1µF ceramic output capacitors (X5R/X7R), as confirmed in the "Region of Stable COUT ESR vs. Load Current" graph. Using 1µF ceramics on each output meets stability requirements across -40°C to +85°C and up to 100mA load - eliminating need for bulkier tantalum or electrolytic types.