Analog Devices Inc./Maxim Integrated MAX8878EZK28+

Overview

MAX8878EZK28+ from Maxim Integrated is a low-noise, low-dropout linear regulator with fixed 2.8V output, 150mA maximum output current, 165mV dropout at full load, 30µVRMS output noise, and 100µA operating supply current. It features auto-discharge during shutdown and reverse battery protection, designed for space-constrained portable electronics requiring stable, clean power from single-cell Li-ion or alkaline sources.

For engineers reviewing the MAX8878EZK28+ datasheet, MAX8878EZK28+ pinout, MAX8878EZK28+ application, or MAX8878EZK28+ equivalent, key selection criteria include its thin SOT23-5 package, 2.8V ±1.4% output accuracy, 10nA shutdown current, thermal/short-circuit protection, and BP-capacitor–enabled noise filtering - all critical for battery-powered handheld instrumentation and communication devices.

Technical Context

The MAX8878EZK28+ 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, enabling precise regulation without external resistors.

It integrates logic-controlled active-low SHDN with 10nA quiescent current and - uniquely versus the MAX8877 - an auto-discharge circuit (300Ω discharge path) that pulls OUT to GND in shutdown. The BP pin connects to a 0.01µF capacitor forming an 80Hz low-pass filter to suppress reference noise, reducing total output noise to 30µVRMS (10Hz–100kHz).

Key Specifications

Pinout & Package

MAX8878EZK28+ is housed in a thin 5-pin SOT23 package (2.9mm × 1.6mm × 0.95mm), optimized for high-density PCB layouts and thermal performance via GND-pad soldering. The package supports reflow and conforms to JEDEC MO-178 standards.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX8878EZK28+, MAX8877EZK28+ removes auto-discharge but retains identical noise and efficiency - making it viable only where output discharge is handled externally; MCP1702T-2802E/MB trades off 83% higher dropout and 33% more noise for lower baseline I_Q, limiting its utility in high-performance portable designs.

Availability

MAX8878EZK28+ is available at Aetrix Electronics and suitable for handheld medical sensors, wireless modem power rails, palm-sized test instruments, and electronic planners requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for MAX8878EZK28+ 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 product line was engineered specifically for battery-powered portable electronics demanding ultra-low noise, minimal dropout, and robust fault protection - targeting cellular handsets, PCMCIA peripherals, and handheld instrumentation where size, efficiency, and signal integrity are critical.

FAQ

What is the output voltage tolerance of the MAX8878EZK28+ over temperature and load?

The MAX8878EZK28+ delivers 2.8V output with ±1.4% accuracy across -40°C to +85°C ambient temperature and 0.1mA to 120mA load current. This specification is guaranteed by production testing and statistical correlation, ensuring consistent performance in real-world portable environments without requiring external calibration.

Does the MAX8878EZK28+ require an external BP capacitor, and what value is recommended?

Yes, the MAX8878EZK28+ requires a 0.01µF ceramic capacitor between BP and GND to achieve its specified 30µVRMS output noise. Larger values (e.g., 0.1µF) marginally reduce noise but increase startup time and shutdown exit delay; values above 0.1µF provide no measurable benefit and are not recommended per the datasheet.

How does the auto-discharge function operate in the MAX8878EZK28+ during shutdown?

When SHDN is pulled low, the MAX8878EZK28+ activates an internal 300Ω discharge path from OUT to GND, actively pulling the output voltage to ground within microseconds. This prevents residual charge from powering downstream circuitry or causing undefined logic states - a feature absent in the pin-compatible MAX8877EZK28+.

What thermal protection mechanisms are built into the MAX8878EZK28+?

The MAX8878EZK28+ incorporates thermal shutdown at +155°C junction temperature with 15°C hysteresis. When triggered, the pass transistor turns off completely, allowing the die to cool; it automatically resumes regulation once temperature falls to +140°C. This protects against sustained overload or poor PCB thermal design without requiring external thermal monitoring.

Can the MAX8878EZK28+ be used with input voltages below 2.5V?

No - the absolute minimum input voltage for the MAX8878EZK28+ is 2.5V, as specified in Absolute Maximum Ratings and Electrical Characteristics. Operation below this threshold risks improper regulation, increased dropout, or failure to maintain 2.8V output; it is not rated for sub-2.5V operation even at light loads.