Analog Devices Inc./Maxim Integrated MAX6339LUT+T

Overview

MAX6339LUT+T from Maxim Integrated is a quad voltage supervisory IC that monitors four independent supply rails-including two user-adjustable thresholds-and asserts a single active-low open-drain RESET signal when any monitored voltage falls below its preset threshold. It operates from IN2 (3.3V supply), draws only 55µA, features 140ms min reset timeout, and remains functional down to IN1 or IN2 = 1V. It is used in multi-rail embedded systems requiring reliable power-up sequencing and brownout detection.

For engineers reviewing the MAX6339LUT+T datasheet, MAX6339LUT+T pinout, MAX6339LUT+T application, or MAX6339LUT+T equivalent, key selection criteria include its dual adjustable input configuration (IN1 and IN4), factory-set +3.3V/2.5V fixed thresholds on IN2/IN3, -5% tolerance accuracy, SOT23-6 package constraints, and compatibility with systems requiring guaranteed operation across -40°C to +85°C.

Technical Context

The MAX6339LUT+T implements four independent precision comparators referenced to a bandgap voltage (1.23V), with internal resistor-divider networks for fixed thresholds and direct comparator inputs for adjustable channels. Its IN1 and IN4 pins are configured as user-adjustable inputs (1.23V threshold), while IN2 and IN3 are factory-trimmed for +3.3V (-5%) and +2.5V (-5%), respectively.

RESET is an open-drain output with 10µA internal pullup to IN2 and guarantees valid state as long as IN1 ≥ 1V or IN2 ≥ 1V. The device uses BiCMOS process (896 transistors), exhibits 0.3% threshold hysteresis, and rejects transients ≤ 100µs at typical overdrive levels-enabling robust operation in noisy industrial and telecom environments.

Key Specifications

Pinout & Package

MAX6339LUT+T is housed in a 6-pin SOT23-6 package (2.9mm × 1.6mm × 1.1mm), optimized for space-constrained PCB layouts and compatible with standard reflow profiles for lead-free assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad voltage supervisory applications.

Compared with MAX6339LUT+T, MAX6340LUT+T offers stricter fixed-threshold tolerances but identical adjustability and package, while TPS3307-33DGNR reduces channel count and eliminates adjustability-making it suitable only for simpler triple-rail systems where external components can cover missing functions.

Availability

MAX6339LUT+T is available at Aetrix Electronics and suitable for telecommunications infrastructure, industrial PLC controllers, and medical imaging subsystems requiring stable component supply, long-term lifecycle assurance, and lead-free compliance.

Supply support for MAX6339LUT+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 semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and computing markets.

The MAX6339LUT+T belongs to Maxim's µP supervisory product line, designed specifically for space- and power-constrained multi-rail systems needing accurate, integrated voltage monitoring without external components.

FAQ

What voltage thresholds does the MAX6339LUT+T monitor by default?

The MAX6339LUT+T monitors IN2 at +3.3V with -5% tolerance (4.25V to 4.50V), IN3 at +2.5V with -5% tolerance (2.13V to 2.25V), and both IN1 and IN4 at an internal 1.23V reference-requiring external resistor dividers to set custom thresholds. This configuration is confirmed in the Selector Guide and Electrical Characteristics table of the official datasheet.

Can the MAX6339LUT+T supervise a negative voltage rail like -12V?

Yes-the MAX6339LUT+T supports negative voltage supervision via IN4 using an external resistor divider. Although its factory option does not include a -5V fixed threshold, the adjustable 1.23V reference allows scaling of -12V (or other negative rails) by connecting R1/R2 such that V_INTH = -12V × R2/(R1+R2) = 1.23V. The datasheet provides explicit design equations and example calculations for this use case.

Is an external pullup resistor required for the MAX6339LUT+T RESET output?

No-MAX6339LUT+T includes a 10µA internal pullup to IN2, sufficient to drive standard CMOS inputs when interfacing with logic powered from the same IN2 rail (e.g., 3.3V). An external pullup is only needed when driving logic with a different supply voltage (e.g., 1.8V or 5V), and must be sized to override the internal pullup without exceeding 20mA sink current rating.

What is the minimum operating voltage for the MAX6339LUT+T to maintain valid RESET output?

The MAX6339LUT+T guarantees valid RESET state as long as either IN1 ≥ 1.0V or IN2 ≥ 1.0V-documented in Note 3 of the Electrical Characteristics table. This allows controlled reset assertion even during deep brownout conditions where main supplies collapse below nominal levels, supporting fail-safe shutdown sequences.

How does the MAX6339LUT+T handle short-duration supply transients?

The MAX6339LUT+T incorporates built-in glitch immunity: it ignores transients shorter than ~100µs at typical overdrive levels, as shown in the "Maximum IN_ Transient Duration vs. Reset Threshold Overdrive" graph (Figure MAX6339toc04). This prevents false resets caused by switching noise, ESD, or load-dump events without requiring external RC filtering.