Analog Devices Inc./Maxim Integrated MAX8888EZK25-T

Overview

MAX8888EZK25-T from Maxim Integrated is a low-dropout linear regulator delivering up to 300mA continuous output at a fixed 2.5V, operating from 2.5V to 5.5V input. It features an open-drain power-OK (POK) flag, 100mV dropout at 200mA, 55µA no-load supply current, and thermal/short-circuit protection - designed for battery-powered portable electronics requiring precise, stable voltage regulation.

For engineers reviewing the MAX8888EZK25-T datasheet, MAX8888EZK25-T pinout, MAX8888EZK25-T application, or MAX8888EZK25-T equivalent, key selection criteria include POK functionality, SOT23-5 package compatibility, 2.5V fixed output accuracy (±3%), dropout performance under load, and shutdown current (<0.2µA).

Technical Context

The MAX8888EZK25-T integrates a p-channel MOSFET pass transistor with R_DS(ON) optimized for low dropout (100mV @ 200mA), eliminating base-drive losses inherent in PNP-based regulators. Its internal 1.25V reference and error amplifier enable tight output regulation across temperature and load.

It implements foldback current limiting (420mA typical at V_OUT ≥93% nominal; 300mA guaranteed continuous), active-low open-drain POK with 92.5% trip threshold (1% hysteresis), and thermal shutdown at +170°C with 20°C hysteresis - all within a 1mm-high 5-pin SOT23 package.

Key Specifications

Pinout & Package

MAX8888EZK25-T is housed in a RoHS-compliant, thin-profile 5-pin SOT23 package (1mm height, Z5-1 footprint), optimized for space-constrained portable PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX8888EZK25-T, the XC6206P252MR-G offers lower shutdown current but sacrifices POK functionality and dropout performance; the ADP125ARZ-2.5-R7 delivers greater output current and soft-start but requires more PCB area and lacks integrated power monitoring.

Availability

MAX8888EZK25-T is available at Aetrix Electronics and suitable for wireless handsets, digital cameras, and notebook computers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX8888EZK25-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 MAX8887/MAX8888 family was developed specifically for portable battery-powered systems needing low-quiescent-current, low-dropout regulation with integrated power monitoring - targeting PDAs, cellular handsets, and compact computing platforms.

FAQ

What is the output voltage tolerance of the MAX8888EZK25-T over temperature and load?

The MAX8888EZK25-T guarantees ±3% output voltage accuracy across the full -40°C to +85°C operating temperature range and for load currents from 100µA to 300mA. At +25°C and 100mA load, typical deviation is ±1.2%. This tolerance ensures reliable operation of 2.5V logic interfaces and analog components without external trimming. The MAX8888EZK25-T maintains this specification using an internal 1.25V bandgap reference and precision feedback divider.

Does the MAX8888EZK25-T require an external bypass capacitor on the BP pin?

No - the BP (bypass) pin is specific to the MAX8887 variant for noise reduction and is not present on the MAX8888EZK25-T. The MAX8888EZK25-T does not include the BP pin or associated low-noise optimization circuitry; its pinout is IN, GND, SHDN, POK, OUT. Therefore, no BP capacitor is needed or supported for the MAX8888EZK25-T. Refer to the MAX8887 datasheet for BP-related design guidance.

What is the minimum input voltage required for the MAX8888EZK25-T to maintain regulation at 300mA output?

The MAX8888EZK25-T requires a minimum input voltage of 2.65V to maintain 2.5V regulation at 300mA load, based on its maximum dropout voltage of 150mV (specified in Electrical Characteristics table). At 200mA, dropout is typically 100mV, allowing regulation down to 2.6V. Input voltage must remain ≥2.5V per Absolute Maximum Ratings, but regulation ceases if VIN falls below VOUT + V_DROPOUT. The MAX8888EZK25-T includes undervoltage lockout that disables operation below ~2.4V to prevent unstable behavior.

How does the POK output behave during shutdown of the MAX8888EZK25-T?

During shutdown (SHDN = GND), the MAX8888EZK25-T actively drives the POK pin low, regardless of output voltage level. This behavior is explicitly defined in the Pin Description and Detailed Description sections: "In shutdown, POK and OUT are driven low." The POK output remains low until SHDN is returned high and VOUT rises above 92.5% of nominal (2.313V), at which point POK transitions to high-impedance. This ensures deterministic reset signaling during power cycling. The MAX8888EZK25-T's POK is open-drain and requires an external pullup resistor for logic-level interpretation.

Can the MAX8888EZK25-T be used with ceramic output capacitors having ESR above 0.1Ω?

No - the MAX8888EZK25-T requires an output capacitor with ESR ≤0.1Ω to ensure stability and optimal transient response, as specified in the Applications Information section. Using higher-ESR capacitors (e.g., tantalum or older-generation ceramics) risks oscillation, overshoot, or poor load-step recovery. The recommended 2.2µF ceramic capacitor must have low ESR and be placed as close as possible to the OUT and GND pins. The MAX8888EZK25-T's internal compensation is optimized for low-ESR ceramic types; deviation invalidates stability guarantees.