Analog Devices Inc./Maxim Integrated MAX8878EZK18-T

Overview

MAX8878EZK18-T from Maxim Integrated is a low-noise, low-dropout linear regulator with 1.8V preset 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 batteries.

For engineers reviewing the MAX8878EZK18-T datasheet, MAX8878EZK18-T pinout, MAX8878EZK18-T application, or MAX8878EZK18-T equivalent, key selection criteria include dropout performance at 150mA, shutdown discharge resistance (300Ω), BP capacitor noise filtering, thermal shutdown behavior (155°C), and SOT23-5 thin-package thermal derating (9.1mW/°C above +70°C).

Technical Context

The MAX8878EZK18-T 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 1.8V regulation (±1.4% over temperature and load).

It integrates logic-controlled shutdown (10nA I_SHDN), thermal overload protection (155°C trip, 15°C hysteresis), short-circuit current limiting (160–390mA), and reverse battery protection that limits reverse current to 1mA. The BP pin connects to a 0.01µF ceramic capacitor to form an 80Hz low-pass filter, reducing output noise to 30µVRMS (10Hz–100kHz).

Key Specifications

Pinout & Package

MAX8878EZK18-T is housed in a 5-pin thin SOT23 package (JEDEC MO-178AA), optimized for thermal performance (θ_JB = 110°C/W) and PCB area savings in handheld devices.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS76318DBVR and MCP1700T-1802E/TT, MAX8878EZK18-T delivers superior noise performance (30µVRMS vs. ≥40µVRMS), lower dropout (165mV vs. ≥220mV), and unique auto-discharge-making it optimal for portable electronics demanding clean, safe, and responsive power sequencing.

Availability

MAX8878EZK18-T is available at Aetrix Electronics and suitable for cellular handsets, PCMCIA cards, palmtop computers, and electronic planners requiring stable component supply, long-term lifecycle support, and traceable sourcing for production programs.

Supply support for MAX8878EZK18-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, communications, and consumer applications.

The MAX8877/MAX8878 product line targets battery-powered portable electronics, delivering ultra-low noise, low dropout, and integrated protection in minimal SOT23 footprints for extended runtime and robust field operation.

FAQ

What is the exact output voltage tolerance of the MAX8878EZK18-T over temperature and load?

The MAX8878EZK18-T guarantees ±1.4% output voltage accuracy across -40°C to +85°C ambient temperature and 0.1mA to 120mA load current, as specified in the Electrical Characteristics table. This tolerance applies to the factory-preset 1.80V output and is measured with VIN ≥ VOUT + 0.5V or 2.5V (whichever is greater). The MAX8878EZK18-T does not require external trimming or calibration to meet this specification.

Does the MAX8878EZK18-T require an external BP capacitor, and what happens if it is omitted?

Yes, the MAX8878EZK18-T requires a 0.01µF ceramic capacitor between BP and GND to achieve its specified 30µVRMS output noise. Omitting the BP capacitor increases output noise to approximately 100µVRMS due to unfiltered bandgap reference noise. The device remains functional but fails to meet low-noise design goals for RF or precision analog circuits. Larger BP capacitors (>0.1µF) increase startup time without improving noise.

How does the auto-discharge feature of the MAX8878EZK18-T operate, and is it present in all variants?

The MAX8878EZK18-T's auto-discharge activates when SHDN is pulled low, connecting a 300Ω internal path from OUT to GND to rapidly discharge the output capacitor. This feature is exclusive to the MAX8878 family (including MAX8878EZK18-T); the MAX8877 variants lack it entirely. Discharge time depends on C_OUT value-for example, a 10µF capacitor discharges to <10% of VOUT in ~330µs.

What thermal derating applies to the MAX8878EZK18-T in its thin SOT23 package?

The MAX8878EZK18-T in thin SOT23-5 has a junction-to-board thermal resistance (θ_JB) of 110°C/W and a continuous power dissipation limit of 727mW at +70°C ambient. Above +70°C, power must be derated by 9.1mW per °C. Effective thermal management requires soldering the GND pin to a minimum 100mm² copper pour; insufficient copper reduces actual power handling by up to 40%.

Can the MAX8878EZK18-T be used with input voltages below 2.5V, and what is the minimum functional VIN?

No, the MAX8878EZK18-T is not guaranteed to operate with input voltages below 2.5V, as stated in Absolute Maximum Ratings and Electrical Characteristics. Its minimum functional input is 2.5V-below this, regulation fails, dropout behavior becomes undefined, and internal circuitry may not bias correctly. For 1.8V output applications with sub-2.5V inputs, a buck-boost or charge-pump solution is required instead.