Analog Devices Inc./Maxim Integrated MAX6324DUT31-T

Overview

MAX6324DUT31-T from Maxim Integrated is a microprocessor supervisory circuit with windowed (min/max) watchdog, open-drain RESET output, and factory-trimmed 3.08V reset threshold (±2.5% accuracy). It monitors +3.3V power supplies in automotive and industrial control systems, asserts RESET low during brownout or manual reset, and pulses WDPO low for 1ms upon fast/slow watchdog timeout faults.

For engineers reviewing the MAX6324DUT31-T datasheet, MAX6324DUT31-T pinout, MAX6324DUT31-T application, or MAX6324DUT31-T equivalent, key selection criteria include its guaranteed RESET validity down to VCC = +1.2V, 100ms minimum reset timeout delay, 6-pin SOT23 package, and AEC-Q100-qualified variants for automotive use.

Technical Context

The MAX6324DUT31-T implements a dual-window watchdog timer that detects both fast faults (WDI falling edges closer than tWD1 = 15ms) and slow faults (no WDI edge longer than tWD2 = 10s), with timing factory-trimmed per suffix 'D'. Its VCC monitor uses a precision comparator with ±2.5% threshold accuracy over –40°C to +125°C, and RESET remains asserted ≥100ms after VCC recovery and MR deassertion.

As an open-drain RESET device, it interfaces directly with bidirectional μP reset pins (e.g., Motorola 68HC11) and supports level-shifting across supply domains via external pullup. WDPO is also open-drain, pulsed low for 1ms on fault detection, and disabled while RESET is asserted.

Key Specifications

Pinout & Package

Package: 6-pin SOT23 (U6+1A), footprint per JEDEC MO-178AA, thermal resistance θJA = 115°C/W on multilayer board.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6324DUT31-T, MAX6324DUT29-T offers lower reset voltage for tighter brownout margins, while MAX6324HUT31-T extends slow watchdog timeout to 1.3s-enabling compatibility with infrequent firmware tasks without altering reset behavior or PCB layout.

Availability

MAX6324DUT31-T is available at Aetrix Electronics and suitable for automotive engine control units, industrial PLC modules, and medical infusion pump controllers requiring stable component supply across extended temperature and long product lifecycles.

Supply support for MAX6324DUT31-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, mixed-signal, and power management ICs for demanding industrial, automotive, and medical applications.

The MAX6323/MAX6324 product line delivers highly accurate, AEC-Q100-qualified supervisory circuits with windowed watchdog functionality specifically for safety-critical embedded systems requiring deterministic reset and fault detection.

FAQ

What is the exact reset threshold voltage of MAX6324DUT31-T?

The MAX6324DUT31-T has a factory-trimmed nominal reset threshold of 3.08V, with guaranteed range of 3.00V to 3.15V (±2.5% accuracy) over –40°C to +125°C. This value is laser-trimmed and specified in the Electrical Characteristics table of the MAX6324 datasheet under "Reset Threshold Voltage" for suffix UT31. The MAX6324DUT31-T uses this precise threshold to reliably monitor +3.3V power rails in automotive and industrial applications.

Does MAX6324DUT31-T support watchdog timeout configuration via external pins or registers?

No, MAX6324DUT31-T does not support dynamic watchdog timeout configuration. Its fast timeout (15ms) and slow timeout (10s) are factory-laser-trimmed and fixed per the 'D' suffix in the part number. These values are permanently set during manufacturing and cannot be altered in-circuit. The MAX6324DUT31-T achieves timing stability and predictability through this one-time trimming, eliminating need for external RC networks or register writes.

Can MAX6324DUT31-T's RESET output drive a standard CMOS microcontroller reset pin directly?

Yes, but only with an external pullup resistor. The MAX6324DUT31-T features an open-drain RESET output, so it requires a pullup resistor (typically 10kΩ) to a valid logic-high voltage (up to +6V) to assert a logic-high level when deasserted. When asserted, it pulls low to <0.4V at 1.2mA sink current. This configuration is compatible with most CMOS μP reset inputs, including bidirectional pins like those on the Motorola 68HC11, and is explicitly validated in the MAX6324DUT31-T application circuit diagrams.

What is the minimum pulse width required on the MR input of MAX6324DUT31-T to trigger reset?

The MR input of MAX6324DUT31-T requires a minimum low pulse width of 1µs to reliably assert the RESET output. This specification is guaranteed across the full operating temperature range (–40°C to +125°C) and is documented in the Electrical Characteristics table under "MR Minimum Pulse Width". The internal debouncing and glitch immunity (100ns) ensure robust operation even in electrically noisy environments, making the MAX6324DUT31-T suitable for direct switch interfacing without external RC filters.

Is MAX6324DUT31-T qualified for automotive applications?

The base MAX6324DUT31-T is not AEC-Q100 qualified; however, the automotive-grade variant MAX6324DUT31/V+T is fully AEC-Q100 qualified and shares identical electrical specifications, reset threshold, and watchdog timing. The MAX6324DUT31-T itself is rated for –40°C to +125°C operation and meets all parametric requirements for automotive use, but formal qualification requires the /V+T suffix. Customers deploying MAX6324DUT31-T in automotive systems should verify compliance requirements against the /V+T version.