Analog Devices Inc./Maxim Integrated MAX6339JUT+

Overview

MAX6339JUT+ from Maxim Integrated is a quad voltage supervisory IC that monitors +5.0V (−5%), +3.3V (−5%), +2.5V (−5%), and +1.8V (−5%) supply rails in multi-rail systems, asserting a single active-low open-drain RESET output when any falls below its threshold. It operates from IN2 supply (1.0V to 5.5V), draws only 55µA typical supply current, and guarantees reset timeout ≥140ms. Used in telecom and industrial computing for system integrity during power-up/down.

For engineers reviewing the MAX6339JUT+ datasheet, MAX6339JUT+ pinout, MAX6339JUT+ application, or MAX6339JUT+ equivalent, key selection criteria include factory-trimmed −5% thresholds across four rails, 0.3% threshold hysteresis for noise immunity, validity of RESET down to IN1 or IN2 = 1V, 6-pin SOT23 footprint, and guaranteed operation from −40°C to +85°C.

Technical Context

The MAX6339JUT+ integrates an accurate bandgap reference, four precision comparators, and internal trimmed resistor-divider networks to implement fixed −5% undervoltage detection on all four inputs. Each comparator includes 0.3% built-in hysteresis relative to its threshold, improving transient immunity without degrading accuracy at nominal voltage.

RESET is open-drain with a 10µA internal pullup to IN2; it remains asserted for ≥140ms after all inputs recover, and stays valid as long as IN1 ≥1V or IN2 ≥1V - enabling reliable reset assertion even during partial rail collapse. The device is powered solely from IN2 and requires no external components for standard configurations.

Key Specifications

Pinout & Package

MAX6339JUT+ is housed in a 6-pin SOT23-6 package (body size 2.9mm × 1.6mm × 1.1mm), optimized for space-constrained PCB layouts in embedded and networking equipment.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6340JUT+ and TPS3307-18DGNR, the MAX6339JUT+ uniquely delivers four-rail supervision with −5% factory thresholds, 140ms min timeout, and RESET validity down to 1V - making it optimal for compact, multi-supply telecom and industrial controllers where simplicity and brownout resilience are prioritized over watchdog capability or ultra-low supply voltage operation.

Availability

MAX6339JUT+ is available at Aetrix Electronics and suitable for telecommunications infrastructure, industrial control systems, and network-attached storage requiring stable component supply, long-term lifecycle support, and guaranteed −40°C to +85°C operation.

Supply support for MAX6339JUT+ 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 demanding industrial, communications, and computing applications.

The MAX6339JUT+ belongs to Maxim's µP supervisory circuit product line, engineered specifically for reliable multi-rail voltage monitoring and reset generation in space- and power-constrained embedded systems.

FAQ

What voltage rails does the MAX6339JUT+ monitor, and what are their exact thresholds?

The MAX6339JUT+ monitors +5.0V (−5% threshold: 4.50V–4.75V), +3.3V (−5%: 3.00V–3.15V), +2.5V (−5%: 2.25V–2.38V), and +1.8V (−5%: 1.53V–1.62V). These are factory-trimmed, fixed thresholds confirmed in the datasheet's Electrical Characteristics table and Selector Guide. No external components are required to achieve these values in the MAX6339JUT+.

Does the MAX6339JUT+ require external pull-up resistors on the RESET pin?

The MAX6339JUT+ includes a 10µA internal pullup to IN2, so no external pullup is required when interfacing with logic referenced to the same IN2 supply. If driving a different logic voltage (e.g., 5V or 1.2V), an external pullup to that rail is needed - the internal pullup prevents reverse current flow, ensuring safe level translation without additional diodes or isolation.

What is the minimum supply voltage required for the MAX6339JUT+ to maintain valid RESET output?

The MAX6339JUT+ guarantees RESET output validity as long as either IN1 ≥ 1.0V or IN2 ≥ 1.0V - confirmed in the Absolute Maximum Ratings and Applications Information sections. This allows continued reset assertion during deep brownout conditions where only one rail remains marginally active, a key reliability feature absent in many competing supervisors.

How does the MAX6339JUT+ handle short-duration supply transients?

The MAX6339JUT+ incorporates 0.3% threshold hysteresis and is designed to ignore transients ≤20µs (for 50mV overdrive), per the Typical Operating Characteristics graph MAX6339toc04. This immunity prevents false resets during switching noise or brief dips, verified across −40°C to +85°C and documented in the Glitch Immunity section of the datasheet.

Is the MAX6339JUT+ pin-compatible with other devices in the MAX6339 family?

Yes - all MAX6339 variants, including MAX6339JUT+, share identical 6-pin SOT23-6 pinout and footprint. The differences lie solely in factory-set threshold configurations (e.g., MAX6339JUT+ = +5V/−5%, +3.3V/−5%, +2.5V/−5%, +1.8V/−5%), not pin function or electrical interface. This enables drop-in replacement within the same package variant when threshold requirements change.