Analog Devices Inc./Maxim Integrated MAX8885EUK50+

Overview

MAX8885EUK50+ from Maxim Integrated is a 5.0V fixed-output, 150mA low-dropout linear regulator with P-channel MOSFET pass element, 85µA no-load supply current, and active-low open-drain Power-OK (POK) output. It operates from +2.5V to +6.5V input, delivers ±1% output accuracy, and is optimized for use with 4.7µF tantalum capacitors (ESR > 0.5Ω) in battery-powered portable electronics.

For engineers reviewing the MAX8885EUK50+ datasheet, MAX8885EUK50+ pinout, MAX8885EUK50+ application, or MAX8885EUK50+ equivalent, key selection considerations include dropout voltage (110mV at 100mA), reverse-battery protection, thermal shutdown at +170°C, and compatibility with high-ESR output capacitors - critical for cost-sensitive PCS/cellular phone power rails.

Technical Context

The MAX8885EUK50+ employs an internal 1.25V bandgap reference and error amplifier driving a 1.1Ω typ P-channel MOSFET pass transistor, enabling ultra-low quiescent current independent of load. Its feedback network is fully internal, setting the fixed 5.0V output without external resistors.

Power-OK monitoring uses an open-drain N-channel comparator with hysteresis (–5.3% threshold), activated only during regulation - disabled in shutdown. Thermal protection triggers at +170°C with +20°C hysteresis, and reverse-battery protection limits reverse current to 1mA when VIN or SHDN falls below GND.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5 (JEDEC MO-178AA), 2.9mm × 1.6mm × 1.1mm body, GND pin serves as thermal path - requires soldering to PCB ground plane for thermal management.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MIC5206-5.0YM5 and MAX8875EUK50+, the MAX8885EUK50+ uniquely combines ultra-low 85µA IQ, reverse-battery protection, and POK monitoring - making it optimal for cost-sensitive, battery-powered designs where tantalum capacitors are preferred and system-level fault detection is required.

Availability

MAX8885EUK50+ is available at Aetrix Electronics and suitable for PCS phones, cellular handsets, and hand-held instruments requiring stable component supply, long-term lifecycle support, and guaranteed parametric performance over –40°C to +85°C.

Supply support for MAX8885EUK50+ 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 MAX8885 series was designed specifically for cost-sensitive, battery-powered portable electronics requiring low IQ, high-ESR capacitor compatibility, and integrated fault monitoring - targeting PCS/cellular phone manufacturers and handheld instrument OEMs.

FAQ

What is the maximum input voltage rating for the MAX8885EUK50+?

The MAX8885EUK50+ has an absolute maximum input voltage of +7V referenced to GND, but its specified operating range is +2.5V to +6.5V. Exceeding +6.5V may cause excessive power dissipation or violate thermal limits, especially at high load currents. The device's 110mV dropout at 100mA means it functions reliably down to VIN = 5.11V while maintaining 5.0V output - critical for single-cell Li-ion systems nearing end-of-discharge.

Does the MAX8885EUK50+ support ceramic output capacitors?

No, the MAX8885EUK50+ is explicitly designed for high-ESR tantalum capacitors (≥0.5Ω) and is unstable with low-ESR ceramic capacitors. Using ceramic caps can cause oscillation or poor transient response due to insufficient phase margin. For ceramic-capacitor compatibility, Maxim recommends the pin-compatible MAX8875EUK50+, which shares the same 5.0V output and SOT23-5 package but uses different internal compensation.

How does the Power-OK (POK) output function on the MAX8885EUK50+?

The POK pin on the MAX8885EUK50+ is an active-low, open-drain output that asserts low when the regulated 5.0V output falls more than 5.3% below nominal (i.e., below 4.74V). It remains inactive during shutdown and requires an external 100kΩ pull-up resistor to OUT for logic-level signaling. This feature enables system-level power sequencing and fault detection without adding discrete comparators or reset ICs.

What thermal management is required for the MAX8885EUK50+ at full 150mA load?

At 150mA and VIN = 6.5V, the MAX8885EUK50+ dissipates ~225mW (P = IOUT × (VIN – VOUT)). With θJA = 140°C/W, this raises junction temperature by ~31.5°C above ambient. To stay within the +150°C absolute max junction limit, the PCB must provide adequate thermal relief: the GND pin must be soldered to a ≥100mm² copper pour acting as a heatsink, and airflow or ambient temperature must be controlled - especially in sealed enclosures.

Is reverse-battery protection active during shutdown of the MAX8885EUK50+?

Yes, reverse-battery protection remains fully active regardless of SHDN state. If VIN or SHDN falls below GND, internal circuitry disconnects parasitic paths and limits reverse current to ≤1mA - protecting both the MAX8885EUK50+ and downstream components. This feature operates independently of regulator enable status and does not require external diodes or FETs, simplifying design for consumer devices where battery polarity errors are common.