Analog Devices Inc./Maxim Integrated MAX6338AUB+T

Overview

MAX6338AUB+T from Maxim Integrated is a quad voltage monitor IC designed for multivoltage system supervision, monitoring +5.0V (−10%), +3.3V (−10%), +2.5V (−10%), and an adjustable input with 1.23V internal reference. It delivers 25µA typical supply current, operates from +2.5V to +5.5V, and guarantees performance across −40°C to +85°C in a 10-pin µMAX package. Used in desktop computers and telecom power sequencing.

For engineers reviewing the MAX6338AUB+T datasheet, MAX6338AUB+T pinout, MAX6338AUB+T application, or MAX6338AUB+T equivalent, key selection criteria include factory-programmed thresholds for four supplies, open-drain active-low outputs with internal 10µA pull-ups, undervoltage lockout below 2.5V, no external components required, and compatibility with wire-ORed "power good" signaling.

Technical Context

The MAX6338AUB+T integrates four independent comparators, each with a dedicated input and open-drain output. All inverting inputs connect to a precision 1.23V bandgap reference; noninverting inputs are accessed via internal resistor dividers preset for +5.0V, +3.3V, and +2.5V nominal supplies at −10% tolerance, while IN4 connects directly to the comparator's noninverting terminal for user-adjustable threshold configuration.

It features built-in 0.3% hysteresis per channel, eliminating need for external feedback networks. An internal undervoltage lockout circuit disables all outputs when VCC falls below 2.5V, and outputs remain low down to VCC = 1V. The device supports wire-ORed outputs and interfaces directly with TTL/CMOS logic without level-shifting.

Key Specifications

Pinout & Package

MAX6338AUB+T is housed in a 10-pin µMAX® package (3.0mm × 3.0mm, 0.6mm height), lead-free, RoHS-compliant, with exposed pad for thermal enhancement.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6338AUB+T, MAX6339AUB+T offers tighter −5% thresholds but identical quad architecture and µMAX footprint, while TPS3307-33DGNR provides Texas Instruments' support ecosystem but sacrifices one monitor channel and requires layout changes.

Availability

MAX6338AUB+T is available at Aetrix Electronics and suitable for desktop computers, telecommunications equipment, and data storage systems requiring stable component supply, long-lifecycle availability, and guaranteed RoHS-compliant manufacturing.

Supply support for MAX6338AUB+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) is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, computing, and communications markets.

The MAX6338AUB+T belongs to Maxim's supervisory IC product line, engineered specifically for reliable, low-power multivoltage monitoring in space-constrained embedded systems where accuracy, temperature stability, and integration reduce bill-of-materials cost.

FAQ

What is the exact threshold voltage for the +5.0V input on MAX6338AUB+T?

The +5.0V input (IN1) on MAX6338AUB+T is factory-trimmed for −10% tolerance, with a guaranteed threshold range of 4.25V to 4.50V as the supply voltage decreases. Typical trip point is 4.38V at +25°C, and the device maintains ±1.5% accuracy across −40°C to +85°C. This specification applies exclusively to the MAX6338AUB+T variant per Maxim's Selector Guide.

Can MAX6338AUB+T monitor a negative voltage like −5.0V?

No, MAX6338AUB+T cannot monitor −5.0V. Its IN1–IN3 inputs are configured for +5.0V, +3.3V, and +2.5V nominal positive supplies at −10% tolerance, and IN4 is an adjustable input referenced to +1.23V. The −5.0V monitoring capability exists only in variants like MAX6338MUB or MAX6338NUB, not in MAX6338AUB+T.

Does MAX6338AUB+T require external resistors for its adjustable input (IN4)?

Yes, MAX6338AUB+T requires two external resistors to configure the adjustable input (IN4) threshold. Since IN4 connects directly to the comparator's noninverting input, a resistor divider between the supply to be monitored and ground-referenced to the internal 1.23V bandgap-is necessary. For example, detecting 4.5V requires R1 ≈ 265kΩ and R2 = 100kΩ.

What happens to MAX6338AUB+T outputs when VCC drops below 2.5V?

When VCC drops below 2.5V, MAX6338AUB+T activates its internal undervoltage lockout (UVLO) circuit, forcing all four outputs (OUT1–OUT4) low regardless of input voltage states. This behavior persists down to VCC = 1V, ensuring clean, predictable reset signaling during brownout or power-down sequences.

Is MAX6338AUB+T pin-compatible with other MAX6338 variants?

Yes, all MAX6338 variants-including MAX6338AUB+T-are pin-compatible and share the same 10-pin µMAX package. Differences lie solely in factory-programmed threshold voltages and tolerances (e.g., −5% vs. −10%), not pin function or physical layout. PCBs designed for any MAX6338_UB variant can accept MAX6338AUB+T without modification.