Analog Devices Inc./Maxim Integrated MAX6339AUT

Overview

MAX6339AUT from Maxim Integrated is a quad voltage supervisory IC that monitors +5.0V (−10%), +3.3V (−10%), +2.5V (−10%), and one user-adjustable input (based on 1.23V internal reference) in multi-rail systems, asserting a single active-low open-drain RESET output when any threshold is violated. It operates from IN2 supply (1.0V to 5.5V), draws only 55µA typical supply current, and guarantees reset timeout ≥140ms - used in telecom power sequencing and industrial embedded controllers.

For engineers reviewing the MAX6339AUT datasheet, MAX6339AUT pinout, MAX6339AUT application, or MAX6339AUT equivalent, key selection criteria include factory-trimmed dual-voltage thresholds with ±0.1% typical accuracy over −40°C to +85°C, immunity to <200µs supply transients, and guaranteed RESET validity down to IN1 or IN2 = 1V - critical for brownout resilience in network equipment and data storage controllers.

Technical Context

The MAX6339AUT integrates four precision comparators with an internal 1.23V bandgap reference and factory-laser-trimmed resistor-divider networks for fixed thresholds on IN1 (+5.0V), IN2 (+3.3V), and IN3 (+2.5V), all with −10% tolerance. The fourth input (IN4) connects directly to the comparator's noninverting input, enabling user-defined monitoring via external resistor divider.

Its reset logic uses a NOR-gated output of all four comparator results, followed by a 140ms minimum timeout monostable circuit referenced to IN2. The open-drain RESET output includes a weak 10µA internal pullup to IN2, eliminating need for external pullup in same-supply interfacing - while supporting overdrive to 0–5.5V logic levels without reverse current flow.

Key Specifications

Pinout & Package

MAX6339AUT is housed in a 6-pin SOT23-6 package (JEDEC MO-178AA), 2.9mm × 1.6mm × 1.1mm body, with gull-wing leads and exposed pad not present. Pin 1 (IN1) is marked by dot; pin numbering follows standard SOT23 counterclockwise from mark.

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 MAX6339AUT uniquely delivers quad monitoring with user-adjustable IN4 in SOT23-6, enabling compact, single-chip supervision of nonstandard rails like 1.2V or −12V - reducing component count and board space where full rail coverage is mandatory.

Availability

MAX6339AUT is available at Aetrix Electronics and suitable for telecommunications infrastructure, industrial PLCs, and enterprise data storage equipment requiring stable component supply with guaranteed long-term availability and lead-free compliance.

Supply support for MAX6339AUT 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) designs precision analog and mixed-signal ICs for power management, sensing, and interface applications - emphasizing high reliability and extended temperature performance.

The MAX6339AUT belongs to Maxim's µP supervisory product line, engineered specifically for multi-rail system integrity in telecom, networking, and industrial control - where simultaneous voltage monitoring and deterministic reset timing are mission-critical.

FAQ

What is the exact reset timeout duration for MAX6339AUT?

The MAX6339AUT guarantees a minimum reset timeout period of 140ms after all monitored inputs rise above their thresholds, with typical value 200ms and maximum 280ms over −40°C to +85°C. This timeout is internally generated and independent of external components - ensuring consistent processor initialization timing across operating conditions. The MAX6339AUT datasheet specifies tRP = 140ms (min), 200ms (typ), 280ms (max).

Can MAX6339AUT monitor negative voltages other than −5V?

Yes - while MAX6339AUT does not include a factory-trimmed −5V option (that variant is MAX6339MUT/NUT/OUT/PUT), its IN4 input is user-adjustable and can monitor negative rails using an external resistor divider. For example, a −12V rail can be scaled to the 1.23V internal reference with R1 = 3.48kΩ and R2 = 2.49kΩ. The MAX6339AUT's absolute input rating allows IN4 down to −6V, supporting such configurations safely.

How does the internal 10µA pullup on MAX6339AUT RESET pin function?

The MAX6339AUT RESET pin features a weak 10µA internal pullup to IN2, eliminating need for external pullup when interfacing with logic powered from the same IN2 rail. If driving a different logic supply (e.g., +5V), an external pullup may be added - the MAX6339AUT's internal circuitry blocks reverse current flow into IN2. This design makes the MAX6339AUT flexible across mixed-voltage systems without compromising rail isolation.

What happens to MAX6339AUT RESET output when IN2 drops below 1V?

When IN2 falls below 1V, the MAX6339AUT RESET output is no longer guaranteed to remain asserted or valid - the device ceases normal operation. However, as long as either IN1 or IN2 stays above 1V, RESET remains functional and correctly reflects input status. This 1V minimum ensures the MAX6339AUT continues supervising during slow discharge of backup supplies, a key feature for graceful shutdown in telecom systems using the MAX6339AUT.

Is MAX6339AUT pin-compatible with other MAX63xx family members?

Yes - all MAX6339 variants (including MAX6339AUT) share identical 6-pin SOT23-6 pinout and footprint. The IN1–IN4 assignments, GND, and RESET positions are fixed across the family. This allows drop-in replacement between variants (e.g., switching from −10% to −5% thresholds) without PCB revision - a verified layout compatibility confirmed in Maxim's Selector Guide and package drawings for the MAX6339AUT and related parts.