Analog Devices Inc./Maxim Integrated MAX6338KUB

Overview

MAX6338KUB from Maxim Integrated is a quad voltage monitor IC designed for multivoltage system supervision, featuring factory-programmed thresholds on IN2 (+3.3V) and IN3 (+2.5V), adjustable thresholds on IN1 and IN4 (based on 1.23V internal reference), and 10% supply tolerance support. It operates from +2.5V to +5.5V, draws 25µA typical supply current, and delivers four independent open-drain active-low outputs in a 10-pin µMAX package-used in desktop computers and industrial equipment for reliable power-good signaling.

For engineers reviewing the MAX6338KUB datasheet, MAX6338KUB pinout, MAX6338KUB application, or MAX6338KUB equivalent, key selection criteria include its dual adjustable inputs, guaranteed -40°C to +85°C operation, internal bandgap reference accuracy (±0.3% threshold hysteresis), and wire-ORable outputs enabling consolidated system reset generation without external logic.

Technical Context

The MAX6338KUB integrates four comparators sharing a precision 1.23V bandgap reference; IN1 and IN4 are auxiliary inputs accepting user-defined thresholds via external resistor dividers, while IN2 and IN3 are fixed at +3.3V and +2.5V with 10% tolerance trip points. Each comparator drives an open-drain output with 10µA weak internal pull-up to VCC, supporting direct interface with TTL/CMOS logic and wire-OR configuration.

An internal undervoltage lockout (UVLO) circuit forces all outputs low when VCC drops below +2.5V, ensuring deterministic behavior during brownout. Threshold accuracy is maintained across temperature (60ppm/°C) and supply voltage variation, with propagation delay under 20µs and output low voltage ≤0.4V at 2mA sink current.

Key Specifications

Pinout & Package

MAX6338KUB is housed in a 10-pin µMAX® package (3.0mm × 3.0mm, 0.6mm height, 0.5mm pitch), thermally enhanced with exposed pad (not electrically connected), compatible with standard surface-mount reflow processes.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV809E33DBZR and ADM1266ACPZ, the MAX6338KUB uniquely balances simplicity (no programming, no external passives) and flexibility (two adjustable inputs + two fixed rails) for cost-sensitive, space-constrained multivoltage systems where analog-only supervision suffices.

Availability

MAX6338KUB is available at Aetrix Electronics and suitable for desktop computers, industrial PLCs, notebook systems, and telecom line cards requiring stable component supply with guaranteed long-term availability and consistent parametric performance.

Supply support for MAX6338KUB 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 semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, computing, communications, and automotive markets.

The MAX6338KUB belongs to Maxim's voltage supervisor product line, engineered for reliable, low-power, multi-rail power integrity monitoring in space- and cost-constrained embedded systems without requiring digital configuration.

FAQ

What is the exact threshold voltage for IN2 and IN3 on the MAX6338KUB?

The MAX6338KUB has factory-programmed thresholds: IN2 monitors +3.3V at -10% tolerance (2.97V trip point), and IN3 monitors +2.5V at -10% tolerance (2.25V trip point). These values are trimmed and guaranteed over -40°C to +85°C, with typical hysteresis of 0.3%. The MAX6338KUB datasheet specifies these as absolute trip thresholds under decreasing input voltage conditions.

Can IN1 and IN4 on the MAX6338KUB monitor negative voltages?

No - IN1 and IN4 on the MAX6338KUB are designed for positive-supply monitoring only, with input voltage range limited to -0.3V to +6V relative to GND. The -5V monitoring capability shown in the MAX6338 family selector guide applies only to variants like MAX6338MUB/N/PUB, which route the -5V input to a dedicated comparator with inverted polarity logic; the MAX6338KUB does not support negative rail monitoring.

Does the MAX6338KUB require external pull-up resistors on its outputs?

The MAX6338KUB includes weak 10µA internal pull-ups to VCC on all four outputs (OUT1–OUT4), so external pull-ups are optional. However, they may be added to drive heavier loads, interface with higher-voltage logic (up to +5.5V), or override the internal pull-up strength. Internal circuitry blocks current flow from external pull-up sources back to VCC, preventing unintended power coupling.

How does the undervoltage lockout (UVLO) function in the MAX6338KUB?

The MAX6338KUB's UVLO circuit forces all four outputs low whenever VCC drops below +2.5V - the minimum operating voltage. This ensures deterministic reset assertion during power ramp-down or brownout, even as VCC falls to +1V (per Absolute Maximum Ratings). The UVLO is internal and always active; no external components or configuration are needed for this behavior in the MAX6338KUB.

What is the recommended bypass capacitor for the MAX6338KUB VCC pin?

A 0.1µF ceramic capacitor placed as close as possible to the VCC pin (Pin 10) and GND (Pin 5) is recommended for the MAX6338KUB to suppress high-frequency noise and ensure stable internal reference operation. This value is specified in the Applications Information section of the MAX6338KUB datasheet and is critical in electrically noisy environments such as switching power supply proximity or dense PCB layouts.