Analog Devices Inc./Maxim Integrated MAX6338CUB

Overview

MAX6338CUB from Maxim Integrated is a quad voltage monitor IC designed for multivoltage system supervision, monitoring +5.0V, +3.3V, +1.8V, and an adjustable input with 10% supply tolerance per channel. It features four independent open-drain active-low outputs, consumes 25µA typical supply current, operates from +2.5V to +5.5V, and guarantees performance across –40°C to +85°C - used in desktop computers and data storage equipment for reliable power-good signaling.

For engineers reviewing the MAX6338CUB datasheet, MAX6338CUB pinout, MAX6338CUB application, or MAX6338CUB equivalent, key selection criteria include factory-programmed threshold combinations (+5V/–10%, +3.3V/–10%, +1.8V/–10%, adjustable), internal 1.23V bandgap reference accuracy (±0.3% over temperature), wire-ORable outputs, undervoltage lockout below 2.5V, and µMAX package compatibility with space-constrained PCB layouts.

Technical Context

The MAX6338CUB integrates four independent comparators, each with its inverting input tied to a precision 1.23V internal bandgap reference and noninverting inputs connected via factory-laser-trimmed resistor dividers to set nominal thresholds. For IN1–IN3, thresholds are fixed at +5.0V (–10%), +3.3V (–10%), and +1.8V (–10%); IN4 is configurable as an auxiliary input with 1.23V internal threshold, enabling user-defined trip points using external resistive dividers.

Each comparator delivers hysteresis of 0.3% (typ), eliminating need for external feedback networks. The device includes an undervoltage lockout circuit that forces all outputs low when VCC drops below 2.5V, and all outputs feature weak 10µA internal pull-ups to VCC - supporting wire-OR configurations without external components while allowing overdrive by external pull-ups up to +5.5V.

Key Specifications

Pinout & Package

The MAX6338CUB is housed in a 10-pin µMAX® package (3.0mm × 3.0mm, 0.6mm height), compatible with standard surface-mount assembly processes and offering high-density integration for compact power management subsystems.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6339CUB and TPS3307-33DBVR, the MAX6338CUB uniquely balances quad-channel coverage, 10% tolerance headroom for noisy environments, and adjustable IN4 - making it optimal for general-purpose multirail supervision where flexibility and robustness outweigh ultra-tight threshold specs.

Availability

MAX6338CUB is available at Aetrix Electronics and suitable for desktop computers, data storage equipment, and networking equipment requiring stable component supply throughout product lifecycles.

Supply support for MAX6338CUB 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 U.S.-based semiconductor company specializing in analog, mixed-signal, and power management ICs for industrial, communications, and computing markets.

The MAX6338 series belongs to Maxim's precision voltage supervisor product line, engineered for high-accuracy, low-quiescent-current monitoring of multiple supply rails in space- and power-constrained systems.

FAQ

What are the factory-programmed threshold voltages for MAX6338CUB?

The MAX6338CUB is factory-configured to monitor +5.0V (–10% threshold = 4.50V min), +3.3V (–10% = 2.85V min), +1.8V (–10% = 1.53V min), and an adjustable input based on the internal 1.23V reference. These values are laser-trimmed and specified in the Electrical Characteristics table under "+5.0V (–10%) Threshold", etc. No external components are needed to achieve these trip points.

Can MAX6338CUB monitor negative voltages like –5.0V?

No - the MAX6338CUB variant is not configured for –5.0V monitoring. That function is assigned to other variants such as MAX6338MUB or MAX6338NUB. The MAX6338CUB's IN4 is designated as an auxiliary input for user-adjustable positive voltage monitoring only, with trip level set by external resistor divider referenced to the +1.23V internal bandgap.

How does the undervoltage lockout (UVLO) function in MAX6338CUB?

The MAX6338CUB's UVLO circuit monitors VCC and forces all four outputs (OUT1–OUT4) low whenever VCC drops below 2.5V. This behavior is guaranteed down to VCC = 1V, ensuring deterministic output states during power-up, brownout, or shutdown sequences - critical for preventing spurious resets in host systems.

Is MAX6338CUB compatible with lead-free soldering processes?

Yes - the MAX6338CUB is offered in both leaded and lead-free packaging. To specify lead-free, append the "+" symbol to the part number (e.g., MAX6338CUB+) when ordering. The µMAX package meets JEDEC J-STD-020 moisture sensitivity level 1 (MSL-1) and supports standard reflow profiles up to 260°C peak.

What is the maximum sink current supported by MAX6338CUB outputs?

Each open-drain output of the MAX6338CUB is rated for continuous sink current up to 20mA. At VCC = +5V and ISINK = 2mA, the output low voltage (VOL) is guaranteed ≤ 0.4V. The internal 10µA pull-up can be overridden by stronger external pull-ups, enabling interface with logic families operating at different voltage levels (e.g., 1.8V, 3.3V, or 5V).