Analog Devices Inc./Maxim Integrated MAX6339IUT-T

Overview

MAX6339IUT-T from Maxim Integrated is a quad voltage supervisory IC that monitors +5.0V, +3.3V, +2.5V, and +1.8V supply rails with ±10% threshold tolerance, delivers active-low open-drain RESET output, features 140ms minimum reset timeout, consumes only 55µA quiescent current, and operates across –40°C to +85°C - used in telecom and industrial embedded systems for reliable power-on reset and brownout detection.

For engineers reviewing the MAX6339IUT-T datasheet, MAX6339IUT-T pinout, MAX6339IUT-T application, or MAX6339IUT-T equivalent, key selection considerations include factory-trimmed four-rail monitoring capability, IN2-powered operation with RESET validity down to 1V on IN1 or IN2, immunity to short transients, no external components required, and SOT23-6 footprint compatibility with space-constrained PCB layouts.

Technical Context

The MAX6339IUT-T integrates an accurate bandgap reference, four precision comparators, and internal resistor-divider networks calibrated for fixed thresholds at +5.0V (–10%), +3.3V (–10%), +2.5V (–10%), and +1.8V (–10%). Each comparator includes 0.3% hysteresis to suppress noise-induced false resets without compromising threshold accuracy.

RESET assertion is governed by NOR logic across all four inputs: any input falling below its threshold (or rising above for negative options - not applicable here) triggers immediate low output; RESET remains asserted for ≥140ms after all inputs recover, ensuring stable µP initialization. Power is derived solely from IN2, and RESET remains valid as long as IN1 ≥1V or IN2 ≥1V.

Key Specifications

Pinout & Package

MAX6339IUT-T is housed in a 6-pin SOT23-6 package (JEDEC MO-178AA), measuring 2.9mm × 1.6mm × 1.1mm, with gull-wing leads and RoHS-compliant lead-free finish (denoted by "+T"; "-T" indicates leaded).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3307-33DGNR and ADM1085AKSZ-REEL7, the MAX6339IUT-T uniquely integrates four precisely trimmed thresholds in one SOT23-6 package with lowest quiescent current and single-rail power dependency - delivering superior integration density and brownout resilience for modern multi-voltage embedded systems.

Availability

MAX6339IUT-T is available at Aetrix Electronics and suitable for telecommunications infrastructure, industrial PLCs, and network switch designs requiring stable component supply, long-term lifecycle assurance, and consistent parametric performance across production batches.

Supply support for MAX6339IUT-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 computing markets.

The MAX6339 belongs to Maxim's µP supervisory product line, engineered specifically for compact, low-power, multi-rail power integrity monitoring in space- and reliability-constrained embedded systems.

FAQ

What voltage rails does the MAX6339IUT-T monitor, and what are their exact thresholds?

The MAX6339IUT-T monitors +5.0V (–10% = 4.50V min), +3.3V (–10% = 2.85V min), +2.5V (–10% = 2.13V min), and +1.8V (–10% = 1.53V min). These thresholds are factory-trimmed and specified over –40°C to +85°C per the datasheet's Electrical Characteristics table. The MAX6339IUT-T does not support user-adjustable thresholds - all four inputs are fixed per the Selector Guide code "I".

Can the MAX6339IUT-T operate if the IN2 supply drops below 3.3V?

Yes - the MAX6339IUT-T remains functional as long as IN2 stays ≥1.0V, and RESET output remains valid under that condition. Its operating supply range is 1.0V to 5.5V on IN2, and the device continues asserting RESET correctly during brownout. This behavior is explicitly guaranteed in the Absolute Maximum Ratings and Electrical Characteristics sections of the MAX6339IUT-T datasheet.

Is an external pullup resistor required for the MAX6339IUT-T RESET output?

No external pullup is required when interfacing with logic referenced to the same IN2 rail (e.g., 3.3V µP), because the MAX6339IUT-T includes a 10µA internal pullup to IN2. An external pullup is needed only when driving logic with a different supply voltage (e.g., 5V or 1.8V), and must be sized to override the internal pullup without exceeding 20mA sink capability.

Does the MAX6339IUT-T provide hysteresis, and how does it affect threshold accuracy?

Yes - each comparator in the MAX6339IUT-T has built-in 0.3% hysteresis relative to its threshold voltage. This prevents chatter during slow supply ramps or noise-induced crossings, without degrading DC threshold accuracy. The hysteresis is factory-trimmed and contributes to the ±1.5% total threshold error specification over temperature for the MAX6339IUT-T.

How is the reset timeout period determined for the MAX6339IUT-T?

RESET remains low for a minimum of 140ms after all monitored inputs rise above their respective thresholds. This timeout is internally generated and guaranteed across –40°C to +85°C, with typical value 200ms and maximum 280ms. It is independent of external components and ensures sufficient hold time for microprocessor initialization - a key timing parameter defined in the MAX6339IUT-T Electrical Characteristics table.