Analog Devices Inc./Maxim Integrated MAX6324BUT29+T

Overview

MAX6324BUT29+T from Maxim Integrated is a microprocessor supervisory circuit with windowed (min/max) watchdog, open-drain RESET output, and factory-trimmed 2.93V reset threshold (±2.5% accuracy). It monitors VCC down to +1.2V, asserts RESET low on brownout or MR activation, and delivers 1ms WDPO fault pulses for fast/slow watchdog timeouts. Used in automotive engine control units requiring AEC-Q100-compliant power sequencing and fault detection.

For engineers reviewing the MAX6324BUT29+T datasheet, MAX6324BUT29+T pinout, MAX6324BUT29+T application, or MAX6324BUT29+T equivalent, key selection criteria include its 2.93V reset threshold, B-windowed watchdog (15ms fast / 100ms slow timeout), -40°C to +125°C operation, SOT23-6 package, and open-drain WDPO/RESET outputs compatible with bidirectional μP reset pins.

Technical Context

The MAX6324BUT29+T implements a dual-threshold watchdog that detects both premature (faster than 15ms) and delayed (slower than 100ms) falling edges on WDI, triggering a 1ms open-drain WDPO pulse. Its reset comparator guarantees valid RESET assertion down to VCC = +1.2V, with 100ms minimum reset timeout after VCC recovery.

It uses laser-trimmed internal references for ±2.5% reset threshold accuracy across -40°C to +125°C and features debounced MR input with 1μs minimum pulse width and 100ns glitch immunity. The open-drain RESET output requires an external pullup and supports level-shifting to supplies up to +6V.

Key Specifications

Pinout & Package

MAX6324BUT29+T is housed in a 6-pin SOT23 package (package code U6+1A, outline 21-0058), optimized for space-constrained PCB layouts and reflow-compatible lead-free assembly (+T suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6324CUT29+T and TLV809E29DBVR, MAX6324BUT29+T uniquely balances fast fault response (15ms) with moderate slow timeout (100ms) - ideal for real-time embedded systems needing rapid hang detection without excessive false triggers from jittery WDI signals.

Availability

MAX6324BUT29+T is available at Aetrix Electronics and suitable for automotive engine control, industrial PLCs, medical infusion pumps, and railway signaling systems requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MAX6324BUT29+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 high-performance analog and mixed-signal ICs for demanding industrial, automotive, and medical applications, with emphasis on reliability and precision.

The MAX6324 series targets safety-critical embedded systems requiring certified watchdog supervision and brownout protection - specifically engineered for AEC-Q100 compliance and extended temperature operation.

FAQ

What is the exact reset threshold voltage of MAX6324BUT29+T and how is it trimmed?

The MAX6324BUT29+T has a nominal reset threshold of 2.93V, with guaranteed range of 2.85V to 3.00V (±2.5% accuracy) across -40°C to +125°C. This value is set via factory laser trimming of internal voltage references, eliminating need for external resistor networks and ensuring stability over temperature and time without recalibration.

How does the windowed watchdog in MAX6324BUT29+T differ from standard watchdog timers?

The MAX6324BUT29+T implements a true min/max watchdog: it triggers WDPO on WDI falling edges occurring either faster than 15ms (fast timeout) or slower than 100ms (slow timeout). This detects both premature returns from ISRs and complete software lockups - unlike single-threshold watchdogs that miss one of these failure modes.

Can MAX6324BUT29+T drive a microcontroller reset pin directly without external components?

Yes, but only with proper external biasing: the MAX6324BUT29+T's open-drain RESET output requires a pullup resistor (typically 10kΩ) to a valid logic supply (≤+6V). This configuration supports bidirectional reset pins (e.g., Motorola 68HC11) and enables level-shifting - no additional drivers or buffers are needed.

What is the minimum pulse width required on the MR input to assert RESET in MAX6324BUT29+T?

The MR input of MAX6324BUT29+T requires a minimum low pulse width of 1μs to reliably assert RESET. The input is internally debounced and rejects transients as short as 100ns, allowing direct connection to mechanical switches or logic gates without external filtering components.

Is MAX6324BUT29+T qualified for automotive applications and what standards does it meet?

Yes, MAX6324BUT29+T is AEC-Q100 qualified (Grade 0: -40°C to +125°C), meeting stress testing requirements for automotive electronics. It is designed for engine control, transmission, and ADAS subsystems where guaranteed reset behavior and watchdog supervision under harsh thermal and electrical conditions are mandatory.