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 asserts a single active-low open-drain RESET output when any monitored supply falls below its threshold, with 140ms minimum timeout and guaranteed operation down to IN1 or IN2 = 1V. Used in telecom infrastructure and industrial computing for reliable power-up sequencing and brownout detection.

For engineers reviewing the MAX6339CUT+T datasheet, MAX6339CUT+T pinout, MAX6339CUT+T application, or MAX6339CUT+T equivalent, key selection considerations include factory-trimmed −10% thresholds for three fixed rails, adjustable fourth input, 55µA quiescent current, SOT23-6 footprint, and immunity to short supply transients without external components.

Technical Context

The MAX6339CUT+T integrates four precision comparators with an internal bandgap reference (1.23V), factory-trimmed resistor-divider networks for +5.0V/−10%, +3.3V/−10%, and +1.8V/−10% thresholds, and one comparator directly referenced to the 1.23V bandgap for user-adjustable monitoring. Each comparator includes 0.3% hysteresis to reject noise near threshold crossings.

Power is derived solely from IN2 (+3.3V), which also serves as the internal pullup source for the open-drain RESET output (10µA typical). RESET remains valid as long as IN1 ≥ 1V or IN2 ≥ 1V, enabling robust reset assertion during partial supply collapse.

Key Specifications

Pinout & Package

MAX6339CUT+T is housed in a 6-pin SOT23-6 package (2.9mm × 1.6mm × 1.1mm), optimized for space-constrained PCB layouts in telecom and embedded systems.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6340CUT+T and TPS3307-33DBVR, the MAX6339CUT+T uniquely delivers quad monitoring with three factory-set −10% thresholds plus one flexible input-enabling full coverage of common multi-rail systems without added components or layout overhead.

Availability

MAX6339CUT+T is available at Aetrix Electronics and suitable for telecommunications infrastructure, industrial PLC controllers, and network-attached storage systems requiring stable component supply and long-term lifecycle support.

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 demanding industrial, automotive, and communications applications.

The MAX6339 series delivers compact, low-power quad voltage supervision for multi-rail systems-targeting telecom line cards, embedded controllers, and data storage equipment where reliability and board space are critical.

FAQ

What voltage thresholds does the MAX6339CUT+T monitor?

The MAX6339CUT+T monitors +5.0V at −10% (4.50V min), +3.3V at −10% (2.85V min), +1.8V at −10% (1.53V min), and one user-adjustable input referenced to a 1.23V internal bandgap. These thresholds are factory-trimmed and guaranteed over −40°C to +85°C. The MAX6339CUT+T does not support −5V monitoring or other fixed thresholds outside this configuration.

Can the MAX6339CUT+T operate if only IN2 is powered?

Yes-the MAX6339CUT+T derives power exclusively from IN2 (+3.3V), and its RESET output remains valid as long as IN2 ≥ 1V or IN1 ≥ 1V. This allows the MAX6339CUT+T to assert and hold RESET during partial supply collapse, such as when IN3 or IN4 drop while IN2 sustains sufficient voltage for internal operation.

How is the adjustable input (IN4) configured on the MAX6339CUT+T?

The MAX6339CUT+T IN4 pin connects directly to a 1.23V internal reference. To monitor a custom voltage (e.g., 2.5V), use an external resistor-divider where V_TH = 1.23V × (R1 + R2)/R2. With ≤100kΩ R2, input bias error stays under 1%. The MAX6339CUT+T datasheet provides exact formulas and design examples for this configuration.

Is an external pullup resistor required for the MAX6339CUT+T RESET output?

No-an internal 10µA pullup to IN2 eliminates the need for an external pullup in most cases. However, if interfacing with logic running at a different voltage (e.g., 5V), an external pullup to that rail is permitted; internal circuitry blocks reverse current flow into IN2. The MAX6339CUT+T RESET output is open-drain and fully compatible with mixed-voltage systems.

What is the minimum supply voltage required for the MAX6339CUT+T to maintain valid RESET assertion?

The MAX6339CUT+T guarantees RESET output validity as long as either IN1 or IN2 remains ≥ 1.0V. Below this, the internal circuitry may become undefined. This 1V margin enables robust reset hold during controlled power-down sequences and ensures the MAX6339CUT+T remains functional longer than many downstream ICs during brownout conditions.