Analog Devices Inc./Maxim Integrated MAX8881EUT33-T

Overview

The MAX8881EUT33-T from Maxim Integrated is a fixed-output 3.3V, 200mA ultra-low-quiescent-current LDO regulator with reverse battery protection and power-ok (POK) output, designed for long-life battery-powered systems such as smoke detectors and smart battery packs.

For engineers reviewing the MAX8881EUT33-T datasheet, MAX8881EUT33-T pinout, MAX8881EUT33-T application, or MAX8881EUT33-T equivalent, key selection criteria include its 3.5µA supply current, ±1.5% output accuracy over –40°C to +85°C, 2.5V–12V input range, 2Ω PMOS pass device, and SOT23-6 package compatibility with space-constrained portable designs.

Technical Context

This LDO employs an internal 1.25V reference and error amplifier to regulate output via a P-channel MOSFET pass transistor-enabling ultra-low quiescent current across full load and dropout conditions. Its feedback node (FB) is internally tied to OUT, eliminating external resistors and ensuring factory-trimmed 3.3V output stability.

The device integrates reverse-battery protection limiting IN-to-GND reverse current to <1mA, thermal shutdown at +160°C (15°C hysteresis), and foldback current limiting. The open-drain POK output asserts low when VOUT drops >10% below nominal or during shutdown, supporting system-level fault detection without external circuitry.

Key Specifications

Pinout & Package

SOT23-6 package (JEDEC MO-178AA, 2.9mm × 2.8mm × 1.3mm body height), lead-free, RoHS-compliant. Exposed pad not present in SOT23 variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS78233DRVT and MCP1825-3302E/DB, the MAX8881EUT33-T uniquely combines sub-4µA quiescent current, 12V input tolerance, reverse-battery immunity, and integrated POK - making it the only option qualified for long-life, unattended, battery-replaceable safety-critical systems.

Availability

MAX8881EUT33-T is available at Aetrix Electronics and suitable for smoke detectors, battery-powered alarms, and remote transmitters requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for MAX8881EUT33-T 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 industrial, automotive, and consumer applications.

The MAX8880/MAX8881 product line was engineered specifically for ultra-long-life battery-powered systems demanding nanoscale quiescent current, reverse-polarity resilience, and integrated power supervision - targeting safety, security, and portable instrumentation markets.

FAQ

What is the maximum input voltage rating for the MAX8881EUT33-T?

The MAX8881EUT33-T supports an absolute maximum input voltage of +14V and a recommended operating range of 2.5V to 12V. Operation above 12V is not specified for performance or reliability; sustained use beyond 12V may compromise output regulation accuracy or long-term parametric stability. The device includes reverse-battery protection that clamps IN-to-GND stress to <1mA at –12V, but the MAX8881EUT33-T itself is not rated for continuous negative input operation.

Does the MAX8881EUT33-T require external feedback resistors to set its output voltage?

No, the MAX8881EUT33-T does not require external feedback resistors. It is a factory-preset 3.3V regulator with internal precision resistive dividers connecting FB to OUT. Pin 4 (FB) must be left unconnected externally - tying it to any other node will disrupt regulation. This contrasts with the adjustable MAX8880 variant, which requires external R3/R4 to set VOUT; the MAX8881EUT33-T achieves ±1.5% output accuracy over temperature without user configuration.

How does the POK output of the MAX8881EUT33-T behave during shutdown?

The POK output of the MAX8881EUT33-T is an open-drain signal that goes low during both output undervoltage (VOUT < 90% of 3.3V) and active shutdown (SHDN ≤ 0.5V). During normal regulation, POK is in high-impedance state and requires an external pull-up resistor to generate a logic-high signal. When SHDN is pulled low, the internal POK comparator disables regulation and forces POK low - providing unambiguous fault indication whether the failure originates from input collapse or intentional disable.

Can the MAX8881EUT33-T operate reliably with a 1µF output capacitor?

Yes, the MAX8881EUT33-T is stable with a 1µF ceramic output capacitor for load currents up to 40mA. For full 200mA operation, Maxim specifies a minimum 4.7µF ceramic capacitor with ESR < 0.5Ω. Using only 1µF at 200mA risks instability, increased output ripple, and degraded transient response - particularly during load steps. The device's stability region chart (Figure MAX8880/1-11) confirms 4.7µF is required to maintain phase margin across the full 0–200mA load range and –40°C to +85°C temperature span.

What thermal protection mechanism does the MAX8881EUT33-T implement?

The MAX8881EUT33-T implements auto-recovering thermal shutdown: when junction temperature exceeds +160°C, the internal thermal sensor triggers shutdown logic, turning off the PMOS pass transistor. After the die cools by 15°C (to ~145°C), the regulator automatically resumes operation. This pulsing behavior prevents permanent damage during sustained overload but is not intended for continuous operation - designers must ensure steady-state power dissipation (IOUT × [VIN – 3.3V]) remains within the SOT23-6 package's 696mW limit at +70°C ambient, derating 8.7mW/°C above that point.