Analog Devices Inc./Maxim Integrated MAX1589EZT180+T

Overview

MAX1589EZT180+T from Maxim Integrated is a low-dropout linear regulator with integrated active-low open-drain RESET output, designed for battery-powered portable systems. It delivers 500mA continuous output current at 1.8V with ±0.5% initial accuracy, 175mV dropout at full load, and operates from a 1.62V–3.6V input supply - enabling operation down to single-cell Li-ion or Li-poly end-of-life voltage. It serves as the primary core voltage regulator in space-constrained handheld devices requiring precise, low-noise power.

For engineers reviewing the MAX1589EZT180+T datasheet, MAX1589EZT180+T pinout, MAX1589EZT180+T application, or MAX1589EZT180+T equivalent, key selection criteria include guaranteed 500mA output under 1.8V V_OUT, 70ms reset delay timing, thermal-overload protection at +165°C, and compatibility with 1µF/4.7µF ceramic bypass capacitors for stable regulation across -40°C to +85°C.

Technical Context

The MAX1589EZT180+T employs an internal P-channel MOSFET pass transistor (R_DS(ON) = 0.33Ω) to achieve low dropout and load-independent quiescent current (90µA typ at 500mA). Its error amplifier compares a precision bandgap reference against a fixed internal feedback divider set for 1.8V output, eliminating external resistor networks.

RESET functionality is implemented via a dedicated power-good comparator monitoring V_OUT with 82.5% nominal threshold and 1.7% hysteresis; the open-drain output remains asserted for ≥70ms after regulation is achieved and falls immediately during brownout or shutdown. Shutdown logic disables the pass transistor, pulls OUT to GND via a 1.5kΩ internal resistor, and reduces supply current to <1µA.

Key Specifications

Pinout & Package

MAX1589EZT180+T is packaged in a 6-pin thin SOT23 (1.1mm height), with pin 1 marked by a dot. The exposed pad (EP) is not present in this variant - only the TDFN version includes thermal EP. Ground connection is shared across pins 2 and 5 for improved thermal conduction and noise immunity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX1589EZT180+T, XC6219B182MR-G trades RESET integration and tighter accuracy for lower cost, while ADP160ACBZ-1.8-R7 sacrifices both current capability and supervision for ultra-low IQ (1.3µA) - making MAX1589EZT180+T the sole option meeting 500mA + RESET + ±0.5% in a 6-pin SOT23.

Availability

MAX1589EZT180+T is available at Aetrix Electronics and suitable for notebook computers, cellular handsets, digital still cameras, and PCMCIA cards requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for MAX1589EZT180+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 MAX1589 series was developed specifically for portable battery-powered equipment demanding low-input-voltage operation, high accuracy, and integrated power-supervision - targeting PDA, smartphone, and ultraportable computing markets in the early 2000s.

FAQ

What is the exact output voltage tolerance of the MAX1589EZT180+T over temperature and load?

The MAX1589EZT180+T guarantees ±0.5% initial output voltage accuracy at +25°C. Over the full -40°C to +85°C operating range and 1mA–500mA load, output voltage accuracy is specified as ±1.5%. This is confirmed in the Electrical Characteristics table under "Output Voltage Accuracy" with conditions VIN = (VOUT + 0.5V) to +3.6V and IOUT = 1mA to 500mA. The MAX1589EZT180+T achieves this via laser-trimmed internal feedback, ensuring stability without external components.

Does the MAX1589EZT180+T require external capacitors, and what are the minimum values?

Yes, the MAX1589EZT180+T requires two external ceramic capacitors: a minimum 1µF capacitor between IN and GND, and a minimum 4.7µF low-ESR capacitor between OUT and GND. These values are mandatory for stability across the full temperature range and up to 500mA load, as specified in the Applications Information section. Using smaller or higher-ESR capacitors risks oscillation or degraded transient response. The MAX1589EZT180+T datasheet explicitly states that surface-mount ceramics with ≤30mΩ ESR are recommended.

How does the RESET output of the MAX1589EZT180+T behave during shutdown?

During shutdown (SHDN = GND), the MAX1589EZT180+T actively pulls the RESET pin low - it does not float or go high-impedance. This behavior is confirmed in the Pin Description: "RESET is actively pulled low" during shutdown. The RESET output remains asserted (low) as long as SHDN is held low or until VOUT drops below 82.5% of nominal, whichever occurs first. This ensures consistent reset signaling during controlled power-down sequences.

What is the thermal performance difference between the SOT23 and TDFN packages for the MAX1589EZT180+T?

The MAX1589EZT180+T is only offered in the 6-pin thin SOT23 package (not TDFN); the TDFN variant uses the "ETT" prefix (e.g., MAX1589ETT180). For the SOT23 version, maximum power dissipation is 727mW at TA = +70°C, with thermal resistance θ_JA ≈ 110°C/W on a 1in² 1oz copper pad. In contrast, the TDFN package achieves 1951mW at +70°C and θ_JA ≈ 41°C/W - more than 2.5× better thermal performance. Thus, the MAX1589EZT180+T is optimized for moderate-power applications where board space limits heat spreading.

Can the MAX1589EZT180+T operate with input voltages below 1.8V?

Yes, the MAX1589EZT180+T operates with input voltages as low as 1.62V - 120mV above its 1.8V output - satisfying the minimum dropout requirement. At 1.8V output, the 175mV dropout specification means it regulates stably down to VIN = 1.975V. Below that, it enters dropout mode but continues supplying current with reduced regulation accuracy. The device's 1.62V absolute minimum input (per Absolute Maximum Ratings) allows operation even with deeply discharged Li-ion cells, a key design goal confirmed in the General Description.