Analog Devices Inc./Maxim Integrated MAX8878EUK18

Overview

MAX8878EUK18 from Maxim Integrated is a low-noise, low-dropout linear regulator with preset 1.8V output, delivering up to 150mA from a 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 MAX8878EUK18 datasheet, MAX8878EUK18 pinout, MAX8878EUK18 application, or MAX8878EUK18 equivalent, key selection criteria include its SOT23-5 package, 1.8V fixed output accuracy (±1.4%), shutdown current of 10nA, auto-discharge resistance of 300Ω, and compatibility with 0.01µF BP capacitor for noise reduction.

Technical Context

The MAX8878EUK18 uses an internal P-channel MOSFET pass transistor (1.1Ω typical R_DS(ON)) enabling low dropout and load-independent 100µA quiescent current. Its error amplifier compares a 1.25V bandgap reference against feedback from an internal resistor divider tied to the OUT pin.

It includes logic-controlled active-low SHDN with 10nA standby current and-uniquely in the MAX8878 variant-an auto-discharge circuit that pulls OUT to GND via 300Ω during shutdown. Protection functions include thermal shutdown at +155°C (15°C hysteresis), short-circuit current limiting (160–390mA), and reverse-battery protection limiting reverse current to 1mA.

Key Specifications

Pinout & Package

MAX8878EUK18 is housed in a 5-pin SOT23-5 regular package (JEDEC MO-178AA), with exposed pad not electrically connected. The GND pin serves dual roles: electrical ground reference and primary thermal path; soldering to a large PCB copper area improves thermal performance and power dissipation capability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS76318DBVR and MCP1700T-1802E/TT, the MAX8878EUK18 uniquely combines ultra-low noise, guaranteed auto-discharge, and industry-standard '2982-compatible pinout - making it optimal for space-constrained, battery-critical designs requiring clean, controllable 1.8V rails.

Availability

MAX8878EUK18 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 consistent parametric performance across temperature and production lots.

Supply support for MAX8878EUK18 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 designed specifically for battery-powered portable electronics demanding low quiescent current, low noise, and robust protection - targeting applications where every microamp and millivolt impacts runtime and reliability.

FAQ

What is the output voltage tolerance of the MAX8878EUK18 over temperature and load?

The MAX8878EUK18 guarantees ±1.4% output voltage accuracy across -40°C to +85°C and for load currents from 0.1mA to 120mA. At 25°C and 0.1mA load, tolerance tightens to ±1.4% (not ±1.0%); this specification applies to all output voltages in the 1.5V–5.0V family including the 1.8V variant. The MAX8878EUK18 achieves this using a trimmed internal resistor divider and a stable 1.25V bandgap reference.

Does the MAX8878EUK18 require an external BP capacitor, and what value is recommended?

Yes, the MAX8878EUK18 requires a 0.01µF ceramic capacitor between BP and GND to achieve its specified 30µVRMS output noise. This capacitor forms a low-pass filter with an internal 200kΩ resistor, reducing reference noise contribution. Values above 0.1µF increase startup time without improving noise; values below 0.01µF degrade noise performance. The MAX8878EUK18 datasheet explicitly specifies 0.01µF as optimal for noise minimization.

How does the auto-discharge function operate in the MAX8878EUK18 during shutdown?

When the SHDN pin is pulled low, the MAX8878EUK18 disables regulation and activates an internal 300Ω discharge path from OUT to GND. This actively pulls the output voltage toward ground, discharging external output capacitance. The discharge rate depends on C_OUT value - for example, a 1µF capacitor discharges to <10% of 1.8V in ~1.5ms. This behavior is exclusive to the MAX8878 series; the MAX8877 lacks this feature.

What thermal protection mechanisms are built into the MAX8878EUK18?

The MAX8878EUK18 incorporates thermal-overload protection that disables the pass transistor when junction temperature exceeds +155°C. After shutdown, the device remains off until the die cools by 15°C (hysteresis), then resumes regulation. This prevents permanent damage during sustained overload or poor PCB thermal design. The SOT23-5 package has θ_JB = 140°C/W (regular) - meaning 150mA at 1.96V input generates ~110mW, raising junction temperature ~15°C above ambient with proper GND pad layout.

Is the MAX8878EUK18 pin-compatible with the industry-standard '2982 regulator?

Yes, the MAX8878EUK18 is explicitly designed as a pin-compatible upgrade to the industry-standard µA78Lxx and MC78Lxx families (collectively referenced as '2982). Pin-for-pin mapping matches IN, GND, SHDN, BP, and OUT across all five terminals in the SOT23-5 package. This allows drop-in replacement in existing designs while delivering lower dropout (165mV vs. typical 300–500mV), lower noise (30µVRMS vs. >100µVRMS), and added features like auto-discharge.