Analog Devices Inc./Maxim Integrated MAX8878EUK27

Overview

MAX8878EUK27 from Maxim Integrated is a low-noise, low-dropout linear regulator with preset 2.7V output, delivering up to 150mA from a 2.5V–6.5V input. It features 165mV dropout at full load, 30µVRMS output noise, 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 MAX8878EUK27 datasheet, MAX8878EUK27 pinout, MAX8878EUK27 application, or MAX8878EUK27 equivalent, key selection criteria include its SOT23-5 regular package, 2.7V ±1.4% output accuracy, 10nA shutdown current, BP-capacitor–enabled noise filtering, and auto-discharge capability unique to the MAX8878 variant.

Technical Context

The MAX8878EUK27 uses an internal P-channel MOSFET pass transistor (1.1Ω typical R_DS(ON)) 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 the OUT pin.

It incorporates dedicated circuitry for auto-discharge (active pull-down of OUT during SHDN), reverse-battery protection (<1mA reverse current), 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 before amplification.

Key Specifications

Pinout & Package

MAX8878EUK27 is housed in a 5-pin SOT23-5 regular package (JEDEC MO-178AA), with exposed pad not electrically connected. Thermal performance relies on GND pin soldering to a large copper area.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX8877EUK27, the MAX8878EUK27 adds auto-discharge without sacrificing noise, accuracy, or thermal robustness; versus XC6206P272MR-G, it delivers superior dropout, lower noise, and comprehensive protection-justifying use in premium portable designs.

Availability

MAX8878EUK27 is available at Aetrix Electronics and suitable for cellular handsets, PCMCIA cards, hand-held instruments, and electronic planners requiring stable component supply, long-term lifecycle support, and guaranteed parametric compliance over -40°C to +85°C.

Supply support for MAX8878EUK27 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 MAX8877/MAX8878 family was designed specifically for battery-powered portable electronics demanding ultra-low noise, minimal dropout, and integrated protection-targeting space-constrained, long-life systems where reliability and efficiency are critical.

FAQ

What is the exact output voltage tolerance of the MAX8878EUK27 over temperature and load?

The MAX8878EUK27 guarantees ±1.4% output voltage accuracy across the full operating range: -40°C to +85°C ambient temperature and 0.1mA to 120mA load current. This specification is confirmed in the Electrical Characteristics table under "Output Voltage Accuracy" with test conditions explicitly referencing VOUT ≥ 2.5V, matching the 2.7V nominal output of MAX8878EUK27.

Does the MAX8878EUK27 require an external capacitor on the BP pin, and what happens if it's omitted?

Yes, the MAX8878EUK27 requires a 0.01µF ceramic capacitor between BP and GND to achieve its specified 30µVRMS output noise. Omitting it increases output noise significantly-data sheet graphs show noise rising to ~70µVRMS at 100kHz with no BP capacitor-and degrades PSRR above 1kHz. The BP capacitor forms a critical 80Hz low-pass filter for the internal bandgap reference.

How does the auto-discharge function of the MAX8878EUK27 operate, and what is its effective resistance?

The MAX8878EUK27's auto-discharge activates when SHDN is pulled low, connecting the OUT pin to GND through an internal ~300Ω resistor. This actively pulls the output voltage to ground within microseconds, preventing residual charge from interfering with downstream logic states. Unlike passive discharge via load leakage, this feature ensures deterministic, rapid VOUT collapse during shutdown.

Can the MAX8878EUK27 be used with input voltages below 2.5V?

No-the MAX8878EUK27 has a minimum input voltage rating of 2.5V per Absolute Maximum Ratings and Electrical Characteristics tables. Operation below 2.5V is not characterized or guaranteed; attempting it may result in unregulated output, increased dropout, or failure to maintain regulation, especially given its 2.7V output requirement.

What thermal considerations apply to the MAX8878EUK27 in SOT23-5 regular package?

The MAX8878EUK27 in SOT23-5 regular package has θ_JB = 140°C/W. To maintain junction temperature ≤+150°C, the PCB must provide adequate thermal conduction-especially via the GND pin, which serves as both electrical return and primary heatsink. For 150mA at 165mV dropout (25mW dissipation), a 40°C ambient requires ≤4400°C/W total thermal resistance, achievable with ≥100mm² copper pour under GND.