Analog Devices Inc./Maxim Integrated MAX1589EZT250+T

Overview

MAX1589EZT250+T from Maxim Integrated is a low-dropout linear regulator with integrated reset output, designed for battery-powered portable electronics. It delivers 500mA continuous output current at 2.5V with ±0.5% initial accuracy, 175mV dropout at full load, and operates from 1.62V to 3.6V input-enabling operation down to single-cell Li-ion or Li-polymer end-of-discharge voltage in notebook computers and digital still cameras.

For engineers reviewing the MAX1589EZT250+T datasheet, MAX1589EZT250+T pinout, MAX1589EZT250+T application, or MAX1589EZT250+T equivalent, key selection criteria include guaranteed 500mA load capability under low-input-voltage conditions, active-low open-drain RESET timing (≥70ms delay), thermal-overload and short-circuit protection, and compatibility with 1µF input / 4.7µF output ceramic capacitor networks.

Technical Context

The MAX1589EZT250+T uses an internal P-channel MOSFET pass transistor (R_DS(ON) = 0.33Ω) to achieve low dropout and supply current independent of load or dropout voltage. Its error amplifier compares a trimmed bandgap reference against internal feedback to regulate output precisely across temperature, line, and load variations.

Reset functionality is implemented via a dedicated power-good comparator monitoring V_OUT, asserting active-low RESET when V_OUT falls below 82.5% of nominal and holding it asserted ≥70ms after regulation is achieved. Shutdown control is logic-level compatible (V_IL ≤ 0.6V, V_IH ≥ 1.4V) with sub-1µA off-state current.

Key Specifications

Pinout & Package

MAX1589EZT250+T is packaged in a 6-pin 3mm × 3mm thin DFN (TDFN) with exposed paddle, optimized for thermal performance in space-constrained portable designs. The package height is <0.8mm, enabling use in ultra-thin notebooks and handheld devices.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS79525DBVR and MCP1825-2502E/DB, the MAX1589EZT250+T uniquely combines 1.62V minimum input, 175mV dropout, and guaranteed 70ms RESET-making it the only option supporting full 2.5V rail regulation across the entire discharge curve of a single Li-ion cell while meeting JEDEC reset timing.

Availability

MAX1589EZT250+T is available at Aetrix Electronics and suitable for notebook computers, digital still cameras, and cellular telephones requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for MAX1589EZT250+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, automotive, and portable applications.

The MAX1589 series was developed specifically for ultra-low-input-voltage, high-accuracy LDO regulation in battery-powered portable equipment-with emphasis on minimal dropout, integrated power-supervision, and compact packaging.

FAQ

What is the maximum input voltage rating for MAX1589EZT250+T?

The MAX1589EZT250+T has an absolute maximum input voltage of +4.0V referenced to GND. However, its operational input voltage range is specified from +1.62V to +3.6V. Exceeding +3.6V during normal operation risks violating electrical specifications and may trigger undervoltage lockout or thermal shutdown. Always maintain VIN within the 1.62V–3.6V window for reliable 2.5V regulation and guaranteed 500mA output.

Does MAX1589EZT250+T require external capacitors, and what values are recommended?

Yes, MAX1589EZT250+T requires external capacitors for stability and performance. A minimum 1µF ceramic capacitor must be placed between IN and GND, and a 4.7µF low-ESR (≤30mΩ) ceramic capacitor between OUT and GND. These values are validated across -40°C to +85°C and ensure adequate phase margin, load-transient response (<35mV overshoot), and PSRR performance. Larger output capacitance improves noise filtering but does not substitute for ESR compliance.

How does the RESET output behave during power-up and brownout events for MAX1589EZT250+T?

The RESET output of MAX1589EZT250+T is an active-low, open-drain signal that asserts low whenever V_OUT falls below 82.5% of 2.5V (i.e., 2.0625V). It remains asserted for at least 70ms after V_OUT rises above regulation, satisfying JEDEC JESD8-12B reset timing. During brownout, RESET falls immediately upon V_OUT droop and reasserts only after stable regulation is restored and the 70ms timer expires-ensuring robust microprocessor reset under all supply fault conditions.

Can MAX1589EZT250+T be used in place of other MAX1589 variants with different output voltages?

No-MAX1589EZT250+T is factory-trimmed for a fixed 2.5V output and is not pin-compatible or functionally interchangeable with other MAX1589 suffixes (e.g., 180 for 1.8V or 300 for 3.0V). Output voltage is set by internal laser trimming during wafer test; no external feedback resistors are present. Substituting with a different voltage variant would violate system rail requirements and is not supported by design or qualification data.

What thermal considerations apply to MAX1589EZT250+T in the 3mm × 3mm TDFN package?

The MAX1589EZT250+T in TDFN package has a θ_JA of ~41°C/W when mounted on a 1in² 1oz copper pad. At 500mA and 1.0V dropout (3.5V_IN → 2.5V_OUT), power dissipation is 500mW-raising junction temperature by ~20.5°C above ambient. To stay within the +150°C max junction limit at +85°C ambient, ensure GND and exposed paddle are fully soldered to ≥1in² copper area. Thermal shutdown activates at +165°C with 15°C hysteresis, providing fault protection but not steady-state design margin.