Analog Devices Inc./Maxim Integrated MAX8888EZK28+T

Overview

MAX8888EZK28+T from Maxim Integrated is a low-dropout linear regulator delivering 300mA continuous output at a fixed 2.85V output voltage, operating from 2.5V to 5.5V input, with 100mV dropout at 200mA and integrated open-drain power-OK (POK) flag for system monitoring in portable battery-powered devices.

For engineers reviewing the MAX8888EZK28+T datasheet, MAX8888EZK28+T pinout, MAX8888EZK28+T application, or MAX8888EZK28+T equivalent, key selection criteria include guaranteed 300mA load capability, POK functionality for reset sequencing, ultra-low 55µA no-load supply current, thermal/short-circuit protection, and SOT23-5 package compatibility in space-constrained designs.

Technical Context

The MAX8888EZK28+T integrates a p-channel MOSFET pass transistor with 0.5Ω R_DS(ON), enabling low dropout and eliminating base-drive current loss typical of PNP-based regulators. Its internal 1.25V reference and error amplifier drive the pass element via feedback from the fixed 2.85V output divider.

It features active-low open-drain POK that asserts when V_OUT falls below 92.5% of nominal (2.64V), with 1% hysteresis, and supports external pullup to OUT for logic-level signaling. Shutdown reduces supply current to 0.1µA while forcing POK and OUT low.

Key Specifications

Pinout & Package

MAX8888EZK28+T is housed in a RoHS-compliant, thin-profile 5-pin SOT23 package (1mm height), optimized for high-density PCB layouts in handheld and wearable electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6206P282MR and AP2204K-2.8TRG1, the MAX8888EZK28+T uniquely combines 2.85V precision, 100mV dropout, POK flag, and 55µA IQ in a single SOT23-5 package - making it the only option supporting robust power sequencing and extended battery life in compact portable designs.

Availability

MAX8888EZK28+T is available at Aetrix Electronics and suitable for wireless handsets, notebook computers, and digital cameras requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for MAX8888EZK28+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) 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 MAX8888EZK28+T belongs to Maxim's low-dropout linear regulator product line, designed specifically for battery-powered portable electronics where ultra-low quiescent current, tight output accuracy, and integrated power-good signaling are essential.

FAQ

What is the output voltage tolerance of the MAX8888EZK28+T over temperature and load?

The MAX8888EZK28+T guarantees ±3% output voltage accuracy across the full operating temperature range (−40°C to +85°C) and load current range (100µA to 300mA). This specification ensures reliable operation for 2.8V–3.0V logic families without requiring external trimming or calibration. The MAX8888EZK28+T achieves this using a precision internal voltage divider and bandgap reference, validated per Maxim's production test flow.

Does the MAX8888EZK28+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 MAX8888EZK28+T. The MAX8888EZK28+T uses a different internal architecture that omits the BP pin; its pin 4 is POK, not BP. Therefore, no BP capacitor is needed or supported for the MAX8888EZK28+T - only standard IN and OUT 2.2µF ceramic capacitors are required.

Can the MAX8888EZK28+T be used with input voltages below 2.5V?

No - the MAX8888EZK28+T has a minimum input voltage rating of 2.5V, enforced by internal undervoltage lockout (UVLO) that disables regulation below ~2.4V (typical). Attempting to operate below this threshold risks unregulated output, POK misassertion, or undefined behavior. For sub-2.5V operation, consider alternative regulators such as the MAX1725 or TPS7A05 series.

How does the POK output behave during shutdown of the MAX8888EZK28+T?

During shutdown (SHDN = GND), the MAX8888EZK28+T actively drives the POK pin low, regardless of output voltage level. This ensures deterministic reset signaling to downstream logic even when the output is collapsing. The POK pin remains low until SHDN is released and VOUT rises above 92.5% of 2.85V (2.64V), at which point POK transitions to high-impedance state - requiring an external pullup resistor for valid logic-high assertion.

Is the MAX8888EZK28+T RoHS-compliant and lead-free?

Yes - the "+T" suffix in MAX8888EZK28+T explicitly denotes a lead(Pb)-free, RoHS-compliant package per Maxim's ordering nomenclature. It uses a matte-tin finish on the SOT23-5 leads and conforms to JEDEC J-STD-020 moisture sensitivity level 1 (MSL-1), enabling standard reflow soldering without special handling requirements.