Analog Devices Inc./Maxim Integrated MAX8868EUK50-T

Overview

MAX8868EUK50-T from Maxim Integrated is a low-noise, low-dropout linear regulator with 5.0V preset output, 150mA output current capability, 30µVRMS output noise, and 165mV dropout at full load. It features auto-discharge on shutdown, reverse battery protection, and operates from 2.5V to 6.5V input-designed for space-constrained portable electronics requiring stable, clean power.

For engineers reviewing the MAX8868EUK50-T datasheet, MAX8868EUK50-T pinout, MAX8868EUK50-T application, or MAX8868EUK50-T equivalent, key selection criteria include its 5.0V fixed output accuracy (±1.4%), 10nA shutdown current, SOT23-5 package compatibility, and auto-discharge functionality not present in the MAX8867 variant.

Technical Context

The MAX8868EUK50-T uses an internal P-channel MOSFET pass transistor (1.1Ω typical R_DS(ON)) enabling ultra-low quiescent current (100µA across all load and dropout conditions) and eliminating base-drive losses inherent in PNP-based regulators. Its error amplifier compares a 1.25V bandgap reference against feedback from an internal resistor divider tied to OUT.

Auto-discharge is implemented via an internal NMOS switch between OUT and GND, activated only when SHDN is logic-low-distinct from the MAX8867 which lacks this function. The BP pin connects to an internal 200kΩ resistor forming an 80Hz low-pass filter with an external 0.01µF capacitor to suppress reference noise.

Key Specifications

Pinout & Package

SOT23-5 regular package (JEDEC MO-178AA), 2.9mm × 1.6mm × 1.1mm body, GND pin serves as thermal pad - requires soldering to large copper area for thermal management per θ_JB = 140°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise, fixed-output LDO applications.

Compared with MAX8868EUK50-T, the MAX8867EUK50-T saves cost but forfeits auto-discharge; the MCP1700T-5002E/TT reduces pin count yet sacrifices reverse protection, BP noise filtering, and dropout performance-making MAX8868EUK50-T optimal for battery-powered systems demanding robustness and ultra-low noise.

Availability

MAX8868EUK50-T is available at Aetrix Electronics and suitable for cellular handsets, PCMCIA cards, palmtop computers, and electronic planners requiring stable component supply, long-lifecycle support, and guaranteed parametric compliance.

Supply support for MAX8868EUK50-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) designs precision analog, mixed-signal, and power-management ICs for demanding industrial, automotive, and portable applications.

The MAX8867/MAX8868 product line targets battery-powered portable electronics needing ultra-low noise, low dropout, and integrated protection - with the MAX8868EUK50-T specifically optimized for 5.0V systems requiring auto-discharge capability.

FAQ

What is the output voltage tolerance of the MAX8868EUK50-T over temperature and load?

The MAX8868EUK50-T delivers 5.0V with ±1.4% accuracy over the full -40°C to +85°C operating temperature range and 0mA to 150mA load current. This specification is production-tested at +25°C and guaranteed across temperature using Statistical Quality Control correlation methods - ensuring consistent 5.0V regulation for critical digital and analog loads in the MAX8868EUK50-T application.

Does the MAX8868EUK50-T require an external capacitor on the BP pin, and what happens if it's omitted?

Yes, the MAX8868EUK50-T requires a 0.01µF ceramic capacitor between BP and GND to achieve its specified 30µVRMS output noise. Omitting this capacitor increases output noise by ~2–3× due to unfiltered bandgap reference noise. The BP pin connects to an internal 200kΩ resistor; without the capacitor, the 80Hz low-pass filter is disabled, degrading noise performance in sensitive analog circuits powered by the MAX8868EUK50-T.

How does the auto-discharge function of the MAX8868EUK50-T operate, and is it controllable?

The MAX8868EUK50-T auto-discharge function activates automatically when the SHDN pin is driven logic-low; an internal NMOS switch connects OUT directly to GND, discharging the output capacitor rapidly. This function is not user-controllable separately - it is intrinsically tied to the SHDN signal. Unlike the MAX8867EUK50-T, the MAX8868EUK50-T provides this feature to prevent residual voltage from interfering with system reset sequencing or causing leakage in powered-down subsystems.

Can the MAX8868EUK50-T be used with input voltages below 2.5V, and what is the absolute minimum?

No - the MAX8868EUK50-T has an absolute minimum input voltage of 2.5V per its Absolute Maximum Ratings table. Operation below 2.5V risks improper regulation, increased dropout, or failure to maintain 5.0V output. The device is designed for 2.5V to 6.5V input; at 5.0V output, the practical lower limit is 5.165V (5.0V + 165mV dropout) to sustain 150mA load. Using the MAX8868EUK50-T outside its specified 2.5V–6.5V range may cause undefined behavior or damage.

What thermal considerations apply to the MAX8868EUK50-T in a SOT23-5 regular package at full load?

In the SOT23-5 regular package, the MAX8868EUK50-T has θ_JB = 140°C/W. At 150mA load with 5.5V input (worst-case power dissipation = 150mA × (5.5V − 5.0V) = 75mW), junction temperature rise is ~10.5°C above ambient - well within limits. However, proper GND pad thermal connection to ≥100mm² copper is mandatory; insufficient copper increases θ_BA, risking thermal shutdown above 85°C ambient. The MAX8868EUK50-T includes thermal shutdown at +155°C with +15°C hysteresis for safety.