Analog Devices Inc./Maxim Integrated MAX6320PUK31BX/V+T

Overview

The MAX6320PUK31BX/V+T from Maxim Integrated is a 5-pin SOT23 microprocessor supervisory circuit with open-drain active-low reset output, manual reset input, and watchdog timer. It features a factory-trimmed 3.08V reset threshold (±2.5% over -40°C to +125°C), 140ms minimum reset timeout, and 1.6s typical watchdog timeout. Designed for brownout protection and system recovery in battery-powered embedded controllers.

For engineers reviewing the MAX6320PUK31BX/V+T datasheet, MAX6320PUK31BX/V+T pinout, MAX6320PUK31BX/V+T application, or MAX6320PUK31BX/V+T equivalent, key selection criteria include its AEC-Q100 qualification, guaranteed reset validity down to VCC = 1V, open-drain RESET output compatible with mixed-voltage systems up to 6V, and immunity to short negative VCC transients ≤4µs.

Technical Context

This device implements a voltage-monitoring comparator with hysteresis (3mV), a programmable reset timeout generator (140ms min), and an independent watchdog timer (1.6s typ) that clears on any WDI edge. The manual reset input includes internal 52kΩ pullup and 100ns glitch rejection.

The open-drain RESET output requires an external pullup resistor (e.g., 10kΩ) to any supply ≤6V and sinks ≥1.2mA at VCC ≥2.7V. Its leakage current is ≤1.0µA, enabling low-power operation in always-on systems.

Key Specifications

Pinout & Package

Package: 5-pin SOT23 (U5+2A), RoHS-compliant, footprint per land pattern 90-0174.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor supervisory applications.

Compared with MAX6320PUK31BX/V+T, MAX6320PUK31DZ/V+T offers extended watchdog coverage at the cost of slower fault response, while TPS3808G33DBVR trades flexibility (no MR/watchdog) for higher threshold precision and lower supply current (1.5µA).

Availability

MAX6320PUK31BX/V+T is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLCs, portable medical monitors, and battery-powered sensor nodes requiring stable component supply across extended temperature ranges.

Supply support for MAX6320PUK31BX/V+T 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 and mixed-signal ICs for demanding industrial, automotive, and communications applications.

The MAX6316–MAX6322 family delivers highly integrated, AEC-Q100-qualified supervisory circuits targeting safety-critical embedded systems needing reliable power monitoring, manual reset, and watchdog functionality in minimal SOT23 packaging.

FAQ

What is the exact reset threshold voltage of the MAX6320PUK31BX/V+T?

The MAX6320PUK31BX/V+T has a factory-trimmed nominal reset threshold of 3.08V, with tolerance of ±2.5% over the full operating temperature range (-40°C to +125°C), resulting in a guaranteed range of 2.99V to 3.17V. This value is derived from the "31" suffix in the part number, referencing Table 1 in the datasheet where "MAX63___31_ _-T" corresponds to 3.08V nominal.

Does the MAX6320PUK31BX/V+T require an external pullup resistor on the RESET pin?

Yes, the MAX6320PUK31BX/V+T features an open-drain RESET output and requires an external pullup resistor. A 10kΩ resistor to any supply up to 6V is recommended per the datasheet. The internal circuitry does not provide pullup; omission will result in undefined RESET logic levels and system failure to initialize properly.

How does the watchdog function behave when the WDI pin is left unconnected on the MAX6320PUK31BX/V+T?

When WDI is left unconnected, the MAX6320PUK31BX/V+T internally services the watchdog timer at intervals equal to 7/8 of the nominal timeout period (i.e., ~1.4s for the Y-version), preventing spurious resets. This allows watchdog functionality to remain enabled without MCU intervention, though explicit WDI toggling is required for precise fault detection.

Is the MAX6320PUK31BX/V+T compatible with 1.8V microcontrollers?

Yes - the MAX6320PUK31BX/V+T's open-drain RESET output is voltage-agnostic and can be pulled up to 1.8V, 3.3V, or 5V. Its VCC supply operates down to 1.0V, and the MR input accepts CMOS logic thresholds (0.3×VCC/0.7×VCC), making it fully interoperable with 1.8V systems when VCC ≥1.8V.

What is the purpose of the "/V" and "+T" suffixes in MAX6320PUK31BX/V+T?

The "/V" denotes AEC-Q100 qualification for automotive applications (Grade 2), while "+T" specifies lead-free (RoHS-compliant) packaging. Together, they confirm the MAX6320PUK31BX/V+T meets automotive reliability standards and environmental compliance requirements for soldering and end-of-life handling.