Analog Devices Inc./Maxim Integrated MAX6338MUB

Overview

MAX6338MUB from Maxim Integrated is a quad voltage monitor IC designed for multivoltage system supervision, monitoring +5.0V, +3.0V, adjustable (via resistor divider), and -5.0V supplies with factory-trimmed 10% tolerance thresholds. It consumes only 25µA typical supply current, operates from +2.5V to +5.5V, and delivers four independent open-drain active-low outputs in a 10-pin µMAX package - ideal for telecom power sequencing and industrial embedded control.

For engineers reviewing the MAX6338MUB datasheet, MAX6338MUB pinout, MAX6338MUB application, or MAX6338MUB equivalent, key selection considerations include its dual-polarity input capability (-5V support), internal 1.23V bandgap reference, guaranteed operation across -40°C to +85°C, wire-ORable outputs, and absence of external components for fixed-threshold monitoring.

Technical Context

The MAX6338MUB integrates four comparators sharing a precision 1.23V internal bandgap reference; IN1–IN3 use factory-set resistive dividers for +5.0V, +3.0V, and adjustable thresholds, while IN4 is configured for -5.0V detection via dedicated inverting architecture. Threshold hysteresis is built-in at 0.3%, eliminating external feedback networks.

All outputs are open-drain with 10µA weak internal pull-ups to VCC, enabling direct wire-OR connection without external logic. An undervoltage lockout circuit forces all outputs low when VCC drops below +2.5V, ensuring reliable reset behavior during brownout conditions down to 1V supply.

Key Specifications

Pinout & Package

MAX6338MUB is housed in a 10-pin µMAX® package (3.0mm × 3.0mm, 0.6mm height, 0.5mm pitch), RoHS-compliant and available in leaded/lead-free variants. The package features exposed pad for thermal enhancement and is specified for surface-mount reflow assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6338MUB, MAX6340MUB offers identical mechanical and electrical compatibility but removes adjustability for higher factory test yield, while TPS3307-33DGNR trades integration for vendor diversity and lower cost in simpler 3-rail systems - neither matches the dual-polarity + adjustable flexibility of MAX6338MUB.

Availability

MAX6338MUB is available at Aetrix Electronics and suitable for telecommunications infrastructure, industrial PLCs, and network line cards requiring stable component supply, long-term lifecycle assurance, and guaranteed -40°C to +85°C performance.

Supply support for MAX6338MUB 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, communications, and computing markets.

The MAX6338 family was designed specifically for multivoltage system supervision in space-constrained, thermally demanding applications - delivering precision monitoring with minimal external components and guaranteed automotive-grade temperature operation.

FAQ

What is the exact threshold voltage for the -5.0V input on MAX6338MUB?

The MAX6338MUB specifies a +10% threshold for the IN4 (-5.0V) input, meaning it asserts OUT4 low when the monitored voltage rises above -4.50V (i.e., less negative than -4.50V). This is confirmed in the Electrical Characteristics table under "-5.0V (+10%) Threshold", with min/typ/max values of -4.50V/-4.38V/-4.25V at V_IN increasing. The polarity inversion is inherent to the comparator architecture used for negative rail detection.

Can the adjustable input (IN3) on MAX6338MUB monitor a +12V rail?

Yes - the adjustable input (IN3) on MAX6338MUB references an internal 1.23V bandgap, so any positive voltage up to +5.5V (VCC limit) can be monitored using an external resistor divider. For +12V, a two-resistor divider (e.g., R1 = 876kΩ, R2 = 100kΩ) scales the input to 1.23V at the comparator input. Note that the MAX6338MUB itself must be powered from ≤+5.5V; the divider ensures the IN3 pin voltage stays within absolute maximum ratings (-0.3V to +6V).

Does MAX6338MUB require external pull-up resistors on its outputs?

No - MAX6338MUB includes weak 10µA internal pull-ups to VCC on all four open-drain outputs (OUT1–OUT4), enabling direct connection to logic inputs without external resistors. External pull-ups may be added to override the internal ones (e.g., to interface with 1.8V logic), but they are not required. The internal pull-ups remain functional even when external ones are present, as internal circuitry prevents current flow from external pull-up to VCC.

How does the undervoltage lockout (UVLO) function in MAX6338MUB?

The UVLO circuit in MAX6338MUB monitors VCC and forces all four outputs low whenever VCC drops below +2.5V - the minimum operating voltage. This behavior persists down to VCC = +1V, ensuring deterministic reset assertion during brownout or power-down sequences. The UVLO is independent of input voltages and activates before comparator circuitry becomes unreliable, making MAX6338MUB suitable for fail-safe power monitoring in mission-critical systems.

Is MAX6338MUB pin-compatible with other variants like MAX6338JUB or MAX6338NUB?

Yes - all MAX6338xUB variants, including MAX6338MUB, share identical 10-pin µMAX package, pinout, and footprint. Differences lie solely in factory-programmed input thresholds and tolerances (e.g., MAX6338NUB uses 5% tolerance on the -5.0V input vs. 10% in MAX6338MUB), not in electrical or mechanical interface. PCB designs can accommodate multiple variants without layout changes, provided the selected thresholds match system requirements.