Analog Devices Inc./Maxim Integrated MAX6338PUB

Overview

MAX6338PUB from Maxim Integrated is a quad voltage monitor IC designed for multivoltage system supervision, monitoring +5.0V, +3.3V, adjustable (via resistor divider), and -5.0V supplies with ±5% tolerance, consuming 25µA typical supply current, and operating from +2.5V to +5.5V VCC - used in telecom power sequencing and industrial embedded control.

For engineers reviewing the MAX6338PUB datasheet, MAX6338PUB pinout, MAX6338PUB application, or MAX6338PUB equivalent, this page delivers verified threshold voltages, open-drain output behavior, µMAX package dimensions, temperature-stable bandgap reference performance, and factory-programmed input configuration specific to MAX6338PUB.

Technical Context

The MAX6338PUB integrates four independent comparators, each with a dedicated open-drain active-low output and internal 10µA pull-up to VCC. Inputs IN1–IN4 are factory configured for +5.0V, +3.3V, adjustable (1.23V reference-based), and -5.0V monitoring, respectively, with trip thresholds guaranteed across -40°C to +85°C.

It uses an internal bandgap reference (1.23V ±3%) with 60ppm/°C tempco and built-in 0.3% hysteresis per comparator - eliminating external hysteresis resistors. An undervoltage lockout circuit forces all outputs low when VCC drops below 2.5V, ensuring reliable reset assertion during brownout.

Key Specifications

Pinout & Package

The MAX6338PUB is housed in a 10-pin µMAX® package (3.0mm × 3.0mm, 0.6mm height, 0.5mm pitch), compatible with standard surface-mount assembly processes and space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6337PUB and TPS3307-33DGNR, the MAX6338PUB uniquely supports −5V supervision in a quad-channel configuration with 5% tolerance on all factory-set inputs - making it the only drop-in solution for legacy analog systems requiring negative rail validation.

Availability

MAX6338PUB is available at Aetrix Electronics and suitable for telecom infrastructure, industrial PLCs, network switch ASIC power-up, and medical diagnostic imaging equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6338PUB 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, mixed-signal, and power management ICs for industrial, automotive, communications, and computing applications.

The MAX6338 series belongs to Maxim's system supervisory product line, engineered specifically for multirail power integrity verification in space- and power-constrained embedded systems with strict reliability requirements.

FAQ

What is the exact input configuration of the MAX6338PUB?

The MAX6338PUB is factory configured to monitor four specific voltage rails: IN1 = +5.0V (−5% threshold), IN2 = +3.3V (−5% threshold), IN3 = adjustable (1.23V internal reference), and IN4 = −5.0V (+5% threshold). This configuration is fixed per the Selector Guide and cannot be altered post-manufacture. The MAX6338PUB datasheet confirms these settings in the Ordering Information table.

Does the MAX6338PUB support monitoring of negative voltages, and how is it implemented?

Yes, the MAX6338PUB supports −5.0V monitoring on IN4 using a dedicated comparator with reversed polarity logic: the output goes low when the −5.0V rail becomes *less negative* than −4.75V (i.e., rises toward ground). This is achieved via internal circuitry optimized for negative input swing, with absolute maximum rating of −6V to +0.3V on IN4. No external level-shifting is needed.

What is the role of the internal 1.23V reference in the MAX6338PUB's adjustable input (IN3)?

The internal 1.23V bandgap reference serves as the trip threshold anchor for IN3. An external resistor divider between VCC and GND sets the actual detection voltage: V_TH = 1.23V × (1 + R1/R2). For example, selecting R1 = 265kΩ and R2 = 100kΩ yields a 4.5V trip point. This reference is trimmed to ±3% and exhibits 60ppm/°C drift, ensuring stable adjustable monitoring across temperature.

Can the MAX6338PUB outputs be connected together, and what design considerations apply?

Yes, all four MAX6338PUB outputs are open-drain with weak internal 10µA pull-ups to VCC, enabling direct wire-OR connection to generate a single "power good" signal. When any monitored rail fails, its output pulls the shared line low. External pull-up voltage must not exceed +5.5V, and internal circuitry blocks reverse current flow - allowing safe interfacing with 3.3V or 5V logic families without level shifters.

How does the undervoltage lockout (UVLO) function affect MAX6338PUB operation during power ramp-up?

The MAX6338PUB's UVLO circuit holds all four outputs low whenever VCC drops below 2.5V - including during initial power ramp-up. This ensures the device remains in a known, inactive state until its own supply is stable. Once VCC exceeds 2.5V, monitoring begins immediately; propagation delay is ≤20µs. The UVLO threshold is internally fixed and not user-adjustable.