Analog Devices Inc./Maxim Integrated MAX1976AEZT300+

Overview

MAX1976AEZT300+ from Maxim Integrated is a low-dropout linear regulator with integrated reset functionality, designed for battery-powered portable systems. It delivers 300mA continuous output current with 100mV dropout at full load, ±0.5% output voltage accuracy, and a fixed 3.0V output. It operates from 1.62V to 3.6V input and features active-low open-drain RESET with 70ms delay, making it suitable for powering microprocessor core or I/O rails in handheld devices.

For engineers reviewing the MAX1976AEZT300+ datasheet, MAX1976AEZT300+ pinout, MAX1976AEZT300+ application, or MAX1976AEZT300+ equivalent, key selection criteria include guaranteed 300mA load capability under low-input-voltage conditions, precise 3.0V output regulation, thermal/short-circuit protection, and the 70ms reset timeout critical for reliable power-on sequencing in space-constrained portable designs.

Technical Context

The MAX1976AEZT300+ uses an internal p-channel MOSFET pass transistor (R_DS(ON) = 0.33Ω) enabling low dropout and supply current independent of load or dropout voltage. Its error amplifier compares a precision bandgap reference against a resistive feedback network to regulate output voltage.

It integrates a dedicated reset comparator monitoring V_OUT, asserting active-low RESET when V_OUT falls below 82.5% of nominal (±2.5% threshold accuracy) and holding it asserted for ≥70ms after regulation is achieved. Shutdown control is logic-level compatible with 0.6V V_IL/1.4V V_IH thresholds and draws <1µA in shutdown.

Key Specifications

Pinout & Package

MAX1976AEZT300+ is housed in a 6-pin thin SOT23 package (1.6mm × 2.9mm × 1.1mm), optimized for high-density portable PCB layouts. The exposed pad is not present in this variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS73030DBVR and MCP1825-3002E/DB, MAX1976AEZT300+ uniquely integrates a 70ms RESET output in the same SOT23 footprint, eliminating need for external supervision while maintaining lowest dropout and highest output accuracy - critical for battery runtime and system reliability in portable medical and communication devices.

Availability

MAX1976AEZT300+ is available at Aetrix Electronics and suitable for smartphone baseband power, digital camera core rails, PCMCIA card I/O, handheld medical monitor displays, and other portable electronics requiring stable component supply with precise 3.0V regulation and integrated reset timing.

Supply support for MAX1976AEZT300+ 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.

MAX1976AEZT300+ belongs to Maxim's low-input-voltage LDO family, engineered specifically for space-constrained, battery-powered portable equipment demanding high accuracy, ultra-low dropout, and integrated power-good supervision.

FAQ

What is the output voltage tolerance of the MAX1976AEZT300+ over temperature and load?

The MAX1976AEZT300+ features ±0.5% output voltage accuracy over load (1mA to 300mA), line (VIN = VOUT + 0.5V to 3.6V), and temperature (−40°C to +85°C). This tight tolerance is achieved through internal laser trimming and is guaranteed across the full operating range - a key differentiator versus standard ±2.5% LDOs. The MAX1976AEZT300+ maintains this accuracy without external components.

Does the MAX1976AEZT300+ require external capacitors, and what are the recommended values?

Yes, the MAX1976AEZT300+ requires two external ceramic capacitors: a 1µF capacitor between IN and GND, and a 4.7µF low-ESR (≤30mΩ) capacitor between OUT and GND. These values ensure stability across temperature and load, optimize transient response, and meet PSRR specifications. Placement must be adjacent to the MAX1976AEZT300+ pins to minimize trace inductance.

How does the RESET function behave during power-down or brownout events?

The MAX1976AEZT300+ RESET output asserts low immediately when VOUT falls below 82.5% of its nominal 3.0V value (i.e., ≤2.475V), including during power-down, input sag, or brownout. It remains asserted until VOUT rises above 2.475V and stays regulated for ≥70ms. This behavior is independent of SHDN state and ensures deterministic reset signaling under all fault conditions.

What thermal protection mechanisms are built into the MAX1976AEZT300+?

The MAX1976AEZT300+ incorporates thermal-overload protection that disables the pass transistor when junction temperature exceeds +165°C. After shutdown, the device re-enables once temperature cools by 15°C (hysteresis), resulting in pulsed output during sustained overload. This protects both the MAX1976AEZT300+ and downstream circuitry without requiring external thermal sensors or intervention.

Can the MAX1976AEZT300+ operate with a 1.8V input supplying a 3.0V output?

No - the MAX1976AEZT300+ cannot regulate 3.0V output from a 1.8V input. Its minimum input voltage is defined as VOUT + dropout voltage. With 3.0V output and 100mV typical dropout, the absolute minimum input is 3.1V. At 1.8V input, the device enters dropout and cannot maintain regulation; output will follow input minus RDS(ON) × ILOAD, falling well below 3.0V.