Analog Devices Inc./Maxim Integrated MAX6339CUT-T

Overview

MAX6339CUT-T from Maxim Integrated is a quad voltage supervisory IC that monitors +5.0V (−10%), +3.3V (−10%), +1.8V (−10%), and one user-adjustable input (1.23V internal reference) in multi-rail systems. It provides 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. Used in telecom and industrial equipment for reliable power-up/down sequencing.

For engineers reviewing the MAX6339CUT-T datasheet, MAX6339CUT-T pinout, MAX6339CUT-T application, or MAX6339CUT-T equivalent, key selection criteria include factory-trimmed thresholds for three fixed rails, adjustable fourth input, reset validity down to IN1/IN2 = 1V, immunity to short transients, and SOT23-6 packaging for space-constrained designs.

Technical Context

The MAX6339CUT-T integrates four precision comparators with an internal bandgap reference (1.23V) and factory-trimmed resistor-divider networks for fixed thresholds. Its architecture supports independent monitoring of four supplies without external components-except when using the adjustable input, which requires an external resistor divider to scale voltages above 1.23V.

Reset assertion is combinatorial: any monitored input falling below its threshold (or rising above for −5V variants-*not applicable here*) triggers immediate RESET low. After all inputs recover, a guaranteed 140ms minimum timeout ensures stable system reset before release. The open-drain RESET output includes a 10µA internal pullup to IN2, eliminating need for external pullup in many 3.3V logic interfaces.

Key Specifications

Pinout & Package

MAX6339CUT-T is housed in a 6-pin SOT23-6 package (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 TPS3307-33D and ADM1085AKSZ-REEL7, the MAX6339CUT-T uniquely delivers integrated supervision of 5V, 3.3V, 1.8V, and a configurable rail in one SOT23-6 package-reducing board area, component count, and qualification effort for complex multi-supply systems.

Availability

MAX6339CUT-T is available at Aetrix Electronics and suitable for telecommunications infrastructure, industrial PLCs, and high-end network printers requiring stable component supply and extended temperature operation.

Supply support for MAX6339CUT-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) designs precision analog and mixed-signal ICs for industrial, communications, and computing markets, with emphasis on reliability and integration.

The MAX6339 product line delivers compact, low-power supervisory circuits for multi-rail systems-targeting applications where space, power, and deterministic reset timing are critical constraints.

FAQ

What is the exact threshold voltage for the +1.8V input on MAX6339CUT-T?

The +1.8V input (IN3) on MAX6339CUT-T has a factory-trimmed threshold of 1.53V minimum (−10% tolerance), 1.58V typical, and 1.62V maximum at +25°C. This specification is guaranteed over the full −40°C to +85°C operating range with 60ppm/°C temperature coefficient. The MAX6339CUT-T uses internal resistor dividers calibrated to match the 1.23V bandgap reference, ensuring consistent trip points across production lots.

Can MAX6339CUT-T monitor a −5V supply?

No, MAX6339CUT-T does not support −5V monitoring. Its Selector Guide specifies IN4 as user-adjustable (1.23V reference), not negative-voltage capable. The −5V option appears in other variants (e.g., MAX6339MUT, MAX6339NUT). Using MAX6339CUT-T for negative rails would require external level-shifting circuitry and invalidate factory-trimmed accuracy-so it is not recommended. Always verify rail compatibility against the specific variant's top-mark code (AAJW for MAX6339CUT-T).

What is the minimum valid supply voltage for MAX6339CUT-T operation?

MAX6339CUT-T remains functional with IN2 ≥ 1.0V, and its RESET output stays valid (correct logic state) as long as either IN1 or IN2 is ≥ 1.0V. Below 1.0V on both pins, RESET behavior is undefined. This 1V operational floor enables controlled shutdown detection in battery-backed or brownout scenarios. The MAX6339CUT-T draws only 55µA at 1.0V, supporting low-voltage supervision without external boost circuitry.

How does the adjustable input (IN4) on MAX6339CUT-T work?

The IN4 pin on MAX6339CUT-T connects directly to a comparator with a precise 1.23V ±0.03V internal reference. To monitor a higher voltage (e.g., 2.5V), use an external resistor divider where V_IN4 = V_TH × R2/(R1+R2). With ≤100kΩ total resistance, input current error stays under 1%. The MAX6339CUT-T datasheet provides the formula R1 = R2 × ((V_INTH/1.23V) − 1) for direct calculation-enabling accurate custom thresholds without trimming.

Is MAX6339CUT-T pin-compatible with other MAX6339 variants?

Yes, all MAX6339 variants-including MAX6339CUT-T-share identical 6-pin SOT23-6 pinout and electrical interface. IN1 through IN4, GND, and RESET retain identical functions across the family. Differences lie solely in factory-trimmed thresholds and internal resistor networks-not pin assignment or timing behavior. This allows design reuse across variants (e.g., swapping MAX6339CUT-T for MAX6339DUT) without PCB changes, provided the new thresholds meet system requirements.