Analog Devices Inc./Maxim Integrated MAX6339OUT

Overview

MAX6339OUT from Maxim Integrated is a quad voltage supervisory IC that monitors +5.0V, +3.3V, user-adjustable, and -5.0V supply rails with ±10% threshold tolerance. It delivers a single active-low open-drain RESET output with 140ms minimum timeout, operates from IN2 supply (1.0V to 5.5V), and draws only 55µA quiescent current. It is used in telecom and industrial equipment for reliable power-on reset and undervoltage detection.

For engineers reviewing the MAX6339OUT datasheet, MAX6339OUT pinout, MAX6339OUT application, or MAX6339OUT equivalent, key selection criteria include its factory-configured four-rail monitoring capability, -5V input support with internal hysteresis, guaranteed operation down to IN1/IN2 = 1V, and SOT23-6 package compatibility with space-constrained embedded systems.

Technical Context

The MAX6339OUT integrates an accurate bandgap reference, four precision comparators, and internal trimmed resistor-divider networks for fixed thresholds (+5.0V, +3.3V, -5.0V) plus one user-adjustable input referenced to 1.23V. Its comparator hysteresis is 0.3% of threshold voltage, enhancing noise immunity without compromising accuracy.

RESET assertion is triggered when any monitored input falls below its threshold (or rises above for -5V), and remains asserted for ≥140ms after all inputs recover. The open-drain output features a 10µA internal pullup to IN2 and remains valid as long as IN1 ≥ 1V or IN2 ≥ 1V - enabling robust reset signaling during brownout conditions.

Key Specifications

Pinout & Package

The MAX6339OUT is housed in a 6-pin SOT23-6 package (body size 2.9mm × 1.6mm × 1.1mm), optimized for high-density PCB layouts and reflow-compatible assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6340AUT and TPS3307-33D, the MAX6339OUT uniquely combines -5V monitoring, user-adjustable threshold flexibility, and ultra-low 55µA quiescent current in the space-constrained SOT23-6 package - making it optimal for compact, multi-rail telecom and industrial systems requiring full rail coverage.

Availability

MAX6339OUT is available at Aetrix Electronics and suitable for telecommunications infrastructure, industrial control systems, and network-attached storage equipment requiring stable component supply and long-term obsolescence management.

Supply support for MAX6339OUT 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 MAX6339OUT belongs to Maxim's µP supervisory product line, designed specifically for space- and power-constrained systems requiring simultaneous multi-rail voltage monitoring with minimal external components.

FAQ

What is the exact threshold voltage for the -5.0V input on the MAX6339OUT?

The MAX6339OUT has a factory-trimmed -5.0V input with +10% tolerance, resulting in a threshold voltage of -4.50V (minimum), -4.38V (typical), and -4.25V (maximum). This means RESET is asserted when the IN4 voltage rises above -4.50V - a design specific to negative-supply undervoltage detection. The MAX6339OUT datasheet confirms this value under Electrical Characteristics, Table 1.

Can the MAX6339OUT monitor a +2.5V supply?

No - the MAX6339OUT does not support +2.5V as a fixed threshold option. Its fixed rails are +5.0V, +3.3V, and -5.0V; the third input (IN3) is user-adjustable via external resistor divider referenced to 1.23V. To monitor +2.5V, configure IN3 with R1/R2 such that V_TH = 1.23V × (R1 + R2)/R2 = 2.5V. The MAX6339OUT supports this configuration per its Applications Information section.

Does the MAX6339OUT require an external pullup resistor on the RESET pin?

No - the MAX6339OUT includes a 10µA internal pullup to IN2, eliminating the need for an external pullup in most cases. However, if interfacing with logic operating at a different voltage (e.g., +5V MCU while IN2 = +3.3V), an external pullup to that logic supply is recommended. The MAX6339OUT RESET output remains valid as long as IN1 or IN2 ≥ 1V, per Absolute Maximum Ratings and Applications Information.

What is the minimum supply voltage required for the MAX6339OUT to assert a valid RESET signal?

The MAX6339OUT guarantees RESET functionality down to IN1 = 1V or IN2 = 1V. Below 1V on both pins, RESET behavior is undefined. This feature allows the MAX6339OUT to maintain reset assertion during deep brownout conditions - a key reliability advantage confirmed in the Electrical Characteristics table (Note 3) and Typical Operating Characteristics (Figure MAX6339toc03).

How does the MAX6339OUT handle short-duration supply transients?

The MAX6339OUT rejects transients ≤200µs duration when the monitored input deviates by ≥50mV from its threshold - verified in the Typical Operating Characteristics (Figure MAX6339toc04). This built-in glitch immunity prevents false resets caused by switching noise or coupling spikes, and is enabled by comparator hysteresis (0.3%) and internal filtering. The MAX6339OUT specification explicitly states immunity to "short monitored supply transients" in its Features list.