Analog Devices Inc./Maxim Integrated MAX6324AUT31-T

Overview

MAX6324AUT31-T from Maxim Integrated is a microprocessor supervisory circuit with windowed (min/max) watchdog timer, open-drain RESET output, and precision +3.08V reset threshold (±2.5% accuracy). It operates from 1.2V to 5.5V supply, consumes 23µA typical current, and guarantees valid RESET down to VCC = +1.2V. Used in automotive engine control units to detect firmware hangs and enforce safe restarts.

For engineers reviewing the MAX6324AUT31-T datasheet, MAX6324AUT31-T pinout, MAX6324AUT31-T application, or MAX6324AUT31-T equivalent, key selection criteria include its factory-trimmed 3.08V reset threshold, dual fault-detection watchdog (fast timeout: 1.5ms min / slow timeout: 10ms min), open-drain WDPO and RESET outputs, guaranteed 100ms reset timeout delay, and AEC-Q100-qualified operation over –40°C to +125°C.

Technical Context

The MAX6324AUT31-T implements a windowed watchdog architecture that detects both fast faults (WDI falling edges closer than tWD1 = 1.5ms) and slow faults (no WDI edge longer than tWD2 = 10ms), with WDPO pulsing low for 1ms on fault detection. Its internal reset comparator monitors VCC against a laser-trimmed 3.08V threshold with ±2.5% accuracy across temperature.

RESET is open-drain and requires an external pullup; it asserts low when VCC drops below 3.08V or MR is pulled low, and remains asserted ≥100ms after VCC rises above threshold and MR deasserts. The device uses BiCMOS process (1371 transistors) and supports bidirectional μP reset pins via its open-drain topology.

Key Specifications

Pinout & Package

MAX6324AUT31-T is housed in a 6-pin SOT23 package (package code U6+1A, outline 21-0058), rated for –40°C to +125°C operation and qualified per AEC-Q100.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6324HUT31-T and TPS3808G33DBVR, the MAX6324AUT31-T uniquely combines precision 3.08V reset, factory-trimmed 1.5ms/10ms windowed watchdog, and AEC-Q100 qualification-making it optimal for automotive and safety-critical embedded systems requiring both voltage and timing fault detection.

Availability

MAX6324AUT31-T is available at Aetrix Electronics and suitable for automotive engine control units, industrial programmable logic controllers, and medical infusion pump controllers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6324AUT31-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 microprocessor supervisory circuits with windowed watchdog functionality specifically engineered for safety-critical systems where both voltage-level and software-execution-timing faults must be detected and acted upon independently.

FAQ

What is the exact reset threshold voltage of MAX6324AUT31-T and how is it trimmed?

The MAX6324AUT31-T has a nominal reset threshold of 3.08V with ±2.5% accuracy over –40°C to +125°C, achieved via laser trimming during manufacturing. This value corresponds to the "31" suffix in the part number and is validated across temperature and supply voltage per the Electrical Characteristics table on page 2 of the datasheet. The MAX6324AUT31-T maintains this precision without external components.

Does MAX6324AUT31-T support connection to microcontrollers with bidirectional reset pins?

Yes, the MAX6324AUT31-T supports bidirectional reset interfaces because its RESET output is open-drain. When paired with a single external pullup resistor, it allows either the MAX6324AUT31-T or the microcontroller to assert reset-enabling clean integration with devices like the Motorola 68HC11. This capability is explicitly documented in the Applications Information section (Figure 7).

What are the watchdog timeout values for MAX6324AUT31-T and how are they configured?

The MAX6324AUT31-T uses the "A" watchdog suffix, providing a fast timeout minimum of 1.5ms and a slow timeout minimum of 10ms. These values are factory-trimmed and fixed-no external configuration is required. The "A" designation is embedded in the part number (MAX6324A...), and timing tolerances are specified in the Watchdog Input and Output table on page 3 of the datasheet.

Can MAX6324AUT31-T operate reliably during severe power supply transients?

Yes, the MAX6324AUT31-T is designed for transient resilience: it ignores negative-going VCC glitches shorter than 20µs (at 100mV under threshold) and is immune to 100ns MR input spikes. Its 500pF VCC bypass requirement and internal glitch rejection ensure robust operation in automotive and industrial environments where load dump or switching noise occurs.

Is MAX6324AUT31-T qualified for automotive applications and what standards does it meet?

Yes, the MAX6324AUT31-T is AEC-Q100 qualified (Grade 0: –40°C to +125°C), as confirmed in the Features section and Ordering Information table. It meets automotive reliability requirements including thermal cycling, humidity testing, and ESD immunity. The "/V" suffix denotes automotive qualification, though MAX6324AUT31-T itself carries the "-T" lead-free industrial variant with identical temperature rating and qualification scope.