Analog Devices Inc./Maxim Integrated MAX6338NUB

Overview

MAX6338NUB from Maxim Integrated is a quad voltage monitor IC designed for multivoltage system supervision, monitoring +5.0V, +3.0V, adjustable, and -5.0V supplies with ±5% tolerance, consuming 25µA typical supply current, operating from +2.5V to +5.5V VCC, and delivering four independent open-drain active-low outputs in a 10-pin µMAX package-used in telecom power sequencing and industrial equipment monitoring.

For engineers reviewing the MAX6338NUB datasheet, MAX6338NUB pinout, MAX6338NUB application, or MAX6338NUB equivalent, this page delivers verified threshold voltages (+5.0V at 4.75V, +3.0V at 2.85V, -5.0V at -4.75V), factory-programmed 5% tolerance, internal 1.23V bandgap reference, wire-ORable outputs, and µMAX thermal performance across -40°C to +85°C.

Technical Context

The MAX6338NUB integrates four comparators sharing a precision 1.23V bandgap reference, with IN1 and IN2 configured for fixed +5.0V and +3.0V thresholds (5% tolerance), IN3 as an adjustable input (1.23V internal reference), and IN4 for -5.0V detection using inverted comparator architecture. Each comparator features built-in 0.3% hysteresis and operates independently without external components.

Its undervoltage lockout circuit disables all outputs when VCC drops below +2.5V, and the four open-drain outputs include weak 10µA internal pull-ups to VCC-enabling direct wire-OR connection to generate a composite "power good" signal while supporting interface with 0V–+5.5V external logic levels.

Key Specifications

Pinout & Package

The MAX6338NUB is housed in a 10-pin µMAX® package (3.0mm × 3.0mm, 0.6mm height, 0.5mm pitch), thermally optimized for high-density PCB layouts and rated for 444mW power dissipation at +70°C with 5.6mW/°C derating above.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6338NUB, MAX6339NUB trades tighter IN3 tolerance for relaxed IN1/IN2/IN4 specs-reducing cost where full 5% coverage isn't required-while TPS3307-33D sacrifices integration and negative-rail support to achieve lower quiescent current (15µA), making it viable only in three-rail systems with no -5V requirement.

Availability

MAX6338NUB is available at Aetrix Electronics and suitable for telecommunications infrastructure, industrial PLCs, and medical imaging equipment requiring stable component supply with guaranteed long-term manufacturability and RoHS-compliant lead-free packaging.

Supply support for MAX6338NUB 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 MAX6338 family was engineered specifically for compact, low-power multirail supervision in space-constrained systems-delivering factory-trimmed accuracy and integrated hysteresis without external components.

FAQ

What is the exact threshold voltage for the +5.0V input on the MAX6338NUB?

The MAX6338NUB's IN1 pin is factory-programmed for +5.0V monitoring with a 5% tolerance, resulting in a precise trip threshold of 4.75V (5% below nominal). This value is guaranteed across -40°C to +85°C and is derived from the internal 1.23V bandgap reference with laser-trimmed resistor dividers. The MAX6338NUB datasheet specifies 4.63V (typ) to 4.75V (max) for the -5% threshold under decreasing input conditions.

How does the MAX6338NUB handle the -5.0V input given its positive-supply architecture?

The MAX6338NUB implements the -5.0V monitoring function on IN4 using an inverted comparator topology referenced to the internal 1.23V bandgap, allowing detection of rising voltage on the negative rail. When IN4 exceeds -4.75V (5% above -5.0V), OUT4 asserts low-enabling fault signaling for negative-rail overvoltage. The MAX6338NUB's absolute maximum rating permits IN4 operation from -6V to +0.3V, ensuring robustness against negative transients.

Can the adjustable input (IN3) on the MAX6338NUB monitor voltages above +5.5V?

No-the MAX6338NUB's IN3 pin is not rated for voltages exceeding the absolute maximum of +6V relative to GND, and its internal 1.23V reference is designed for use with resistor dividers that scale down higher voltages. To monitor >+5.5V rails, an external resistive divider must be used to attenuate the input to ≤+6V while maintaining sufficient signal-to-noise ratio. The MAX6338NUB itself does not provide level-shifting or isolation for overvoltage inputs.

What is the output behavior of the MAX6338NUB when VCC drops below 2.5V?

When VCC falls below +2.5V, the MAX6338NUB's internal undervoltage lockout circuit activates, forcing all four outputs (OUT1–OUT4) low regardless of input conditions. This behavior is guaranteed down to VCC = +1V, preventing erratic reset signaling during brownout. The MAX6338NUB's datasheet confirms this feature ensures deterministic fault reporting even during severe supply collapse.

Is the MAX6338NUB pin-compatible with other variants in the MAX6338 family, such as MAX6338AUB or MAX6338JUB?

Yes-the MAX6338NUB shares identical pinout, package (10-pin µMAX), and electrical interface with all members of the MAX6338 family, including MAX6338AUB and MAX6338JUB. Differences exist only in factory-programmed threshold voltages and tolerances; no PCB layout changes are required when substituting between variants. The MAX6338NUB's pin configuration is fully documented in the Maxim datasheet Figure 1 and Pin Description table.