Analog Devices Inc./Maxim Integrated MAX8878EUK25+T

Overview

MAX8878EUK25+T from Maxim Integrated is a low-noise, low-dropout linear regulator with fixed 2.5V output, delivering up to 150mA from 2.5V–6.5V input. It features 30µVRMS output noise, 165mV dropout at 150mA, and 100µA operating supply current. Designed for battery-powered portable electronics, it integrates reverse-battery protection, thermal shutdown, and auto-discharge functionality.

For engineers reviewing the MAX8878EUK25+T datasheet, MAX8878EUK25+T pinout, MAX8878EUK25+T application, or MAX8878EUK25+T equivalent, key selection criteria include dropout performance under load, shutdown leakage (10nA), output accuracy (±1.4%), BP-capacitor–dependent noise reduction, and SOT23-5 thin-package thermal resistance (θJB = 110°C/W).

Technical Context

The MAX8878EUK25+T uses an internal P-channel MOSFET pass transistor (R_DS(ON) ≈ 1.1Ω) to achieve low dropout and eliminate base-drive current loss. Its error amplifier compares a 1.25V bandgap reference against feedback from an internal resistor divider tied to OUT, enabling stable regulation without external resistors.

It incorporates dedicated circuitry for auto-discharge (active pull-down of OUT during SHDN), reverse-battery protection (limits reverse current to 1mA), and thermal shutdown at +155°C with 15°C hysteresis. The BP pin connects to a 0.01µF capacitor forming an 80Hz low-pass filter that reduces reference noise, directly contributing to its 30µVRMS output noise specification.

Key Specifications

Pinout & Package

SOT23-5 thin package (JEDEC MO-178AA), 2.9mm × 1.6mm × 1.1mm body height, with exposed pad thermally connected to GND. GND pin serves dual role as electrical ground and primary heat path; requires soldering to large PCB copper area for thermal management (θJB = 110°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS76325DBVR and MCP1702T-2502E/MB, the MAX8878EUK25+T delivers superior noise performance and integrated auto-discharge, enabling simpler, more robust designs in battery-critical portable systems - especially where fast, complete output discharge and long shelf-life are required.

Availability

MAX8878EUK25+T is available at Aetrix Electronics and suitable for cellular telephones, PCMCIA cards, and hand-held instruments requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for MAX8878EUK25+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 U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for demanding applications.

The MAX8877/MAX8878 product line was designed specifically for battery-powered portable electronics requiring ultra-low noise, low dropout, and minimal quiescent current - targeting cellular handsets, PDAs, and instrumentation where efficiency and signal integrity are critical.

FAQ

What is the maximum input voltage rating for the MAX8878EUK25+T?

The MAX8878EUK25+T has an absolute maximum input voltage of +7V relative to GND. However, its functional operating range is specified from 2.5V to 6.5V. Exceeding 6.5V may cause excessive power dissipation or violate internal voltage limits, even if within absolute ratings. Always maintain VIN ≤6.5V in normal operation to ensure reliability and meet datasheet performance guarantees.

Does the MAX8878EUK25+T require an external feedback resistor network?

No, the MAX8878EUK25+T does not require external feedback resistors. It features a factory-trimmed internal resistor divider that sets the output to a precise 2.5V ±1.4% across temperature and load. This eliminates component count, layout area, and potential errors from external resistor tolerances or thermal drift - simplifying design and improving long-term stability.

How does the BP pin affect startup time and noise performance in the MAX8878EUK25+T?

The BP pin connects to a 0.01µF capacitor that forms an 80Hz low-pass filter for the internal reference, reducing output noise to 30µVRMS. Increasing BP capacitance lowers noise further but lengthens startup and shutdown exit delays - e.g., 0.1µF raises exit delay to ~300µs. Capacitors >0.1µF provide negligible noise benefit and are not recommended per the datasheet.

Can the MAX8878EUK25+T be used with ceramic output capacitors having high temperature coefficient dielectrics like Y5V?

Y5V and Z5U ceramics exhibit large capacitance and ESR shifts with temperature, risking instability below -10°C. For MAX8878EUK25+T, X7R or X5R dielectrics are recommended: 1µF suffices for VOUT ≥2.5V across -40°C to +85°C. If using Y5V/Z5U, capacitance must be increased ≥2× to maintain minimum 1µF effective value at low temperature and ensure loop stability.

What thermal considerations apply to the MAX8878EUK25+T in its SOT23-5 thin package?

The MAX8878EUK25+T in thin SOT23-5 has θJB = 110°C/W. To keep junction temperature ≤+150°C, the GND pin must be soldered to a large PCB copper area acting as a heatsink. With 150mA load and 2.665V input (165mV dropout), power dissipation is 24.9mW - resulting in ~2.7°C rise above board temperature. Adequate GND copper area is essential for higher ambient or sustained load conditions.