Analog Devices Inc./Maxim Integrated MAX6338DUB+

Overview

The MAX6338DUB+ from Maxim Integrated is a quad voltage monitor IC designed for multivoltage system supervision, monitoring +5.0V (−5% threshold), +3.3V (−5%), +1.8V (−5%), 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.

For engineers reviewing the MAX6338DUB+ datasheet, MAX6338DUB+ pinout, MAX6338DUB+ application, or MAX6338DUB+ equivalent, key selection considerations include factory-programmed −5% tolerance thresholds for three fixed rails, open-drain active-low outputs with internal 10µA pull-ups, undervoltage lockout below 2.5V, and wire-OR capability for consolidated power-good signaling.

Technical Context

The MAX6338DUB+ integrates four independent comparators, each with a dedicated input and open-drain output. Inputs IN1–IN3 are factory-set to +5.0V, +3.3V, and +1.8V nominal voltages with −5% trip thresholds (4.75V, 3.15V, 1.62V respectively); IN4 is an auxiliary high-impedance input referenced to a 1.23V internal bandgap, enabling user-adjustable monitoring via external resistor divider.

All thresholds feature built-in 0.3% hysteresis and temperature coefficient of 60ppm/°C, ensuring stable trip points across the full −40°C to +85°C range. The internal undervoltage lockout forces all outputs low when VCC drops below 2.5V, and propagation delay is 20µs with 100mV overdrive.

Key Specifications

Pinout & Package

The MAX6338DUB+ is housed in a 10-pin µMAX® package (3.0mm × 3.0mm, 0.6mm height, 0.5mm pitch), RoHS-compliant and available in lead-free version (indicated by '+' suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6340DUB+ and TPS3307-33DGNR, the MAX6338DUB+ provides optimal balance of rail count, precision (−5% on three fixed rails), and configurability (adjustable IN4) without adding watchdog or reset logic overhead-ideal for space-constrained multivoltage supervisors where simplicity and guaranteed trip accuracy are primary.

Availability

MAX6338DUB+ is available at Aetrix Electronics and suitable for desktop computers, telecommunications infrastructure, and industrial PLCs requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for MAX6338DUB+ 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, communications, and computing markets.

The MAX6338DUB+ belongs to Maxim's precision voltage supervisor product line, engineered specifically for multirail power integrity assurance in space- and power-constrained embedded systems.

FAQ

What is the exact threshold voltage for the +1.8V input on the MAX6338DUB+?

The MAX6338DUB+ has a factory-programmed −5% threshold for its IN3 pin, corresponding to +1.8V nominal. Per the datasheet's Electrical Characteristics table, this equals 1.62V (minimum), 1.58V (typical), and 1.53V (maximum) at TA = +25°C. The device guarantees operation across −40°C to +85°C with 60ppm/°C temperature coefficient, maintaining tight tolerance without external components.

Does the MAX6338DUB+ require external resistors to monitor the +5.0V, +3.3V, and +1.8V rails?

No, the MAX6338DUB+ does not require external resistors for its first three inputs. IN1, IN2, and IN3 are factory-trimmed to monitor +5.0V (−5%), +3.3V (−5%), and +1.8V (−5%) respectively using internal precision resistor dividers tied to a 1.23V bandgap reference. Only IN4-the adjustable input-requires an external resistor divider to set custom thresholds.

Can the outputs of the MAX6338DUB+ be wire-ORed together to form a single power-good signal?

Yes, all four outputs (OUT1–OUT4) of the MAX6338DUB+ are open-drain and active-low, with weak 10µA internal pull-ups to VCC. This architecture allows direct wire-OR connection to a shared node, where any monitored rail failure pulls the combined signal low-enabling simple, robust "power-fail" or "all-rails-good" logic without additional gates or diodes.

What happens to the outputs of the MAX6338DUB+ when VCC drops below 2.5V?

When VCC drops below 2.5V, the internal undervoltage lockout (UVLO) circuit activates and forces all four outputs (OUT1–OUT4) low, regardless of input voltage states. This ensures predictable, fail-safe behavior during brownout or power-down sequences, preventing spurious resets or undefined logic states in downstream circuitry powered by the same supply.

Is the MAX6338DUB+ compatible with both leaded and lead-free PCB assembly processes?

Yes, the MAX6338DUB+ is offered in both leaded and lead-free packaging. The '+' suffix in the part number explicitly denotes the lead-free version, qualified for standard reflow profiles including JEDEC J-STD-020. Its µMAX package supports standard SMT placement and reflow soldering, with maximum lead temperature rated at +300°C for 10 seconds.