Analog Devices Inc./Maxim Integrated MAX6324GUT26

Overview

MAX6324GUT26 from Maxim Integrated is an open-drain µP supervisory circuit with windowed (min/max) watchdog, precision reset threshold of 2.70V (±2.5%), guaranteed RESET validity down to VCC = +1.2V, and 1ms WDPO fault pulse - used in automotive engine control units to detect firmware hang or clock skew during cold-cranking conditions.

For engineers reviewing the MAX6324GUT26 datasheet, MAX6324GUT26 pinout, MAX6324GUT26 application, or MAX6324GUT26 equivalent, this page delivers verified electrical parameters, SOT23-6 terminal mapping, factory-trimmed watchdog timing (G-fast / U-slow), reset threshold tolerance, and real-world interface guidance for bidirectional µP reset pins and WDPO-to-MR loopback.

Technical Context

The MAX6324GUT26 implements a dual-window watchdog timer measuring intervals between falling edges on WDI: fast timeout (tWD1 = 29ms min / 39ms max) and slow timeout (tWD2 = 82ms min / 108ms max), both laser-trimmed and stable over −40°C to +125°C. It uses a BiCMOS process with 1371 transistors to achieve ±2.5% reset threshold accuracy across voltage and temperature.

Its open-drain RESET output supports level-shifting across supply domains (e.g., monitoring +3.3V while pulling up to +5V), and WDPO pulses low for exactly 1ms upon fault detection - independent of RESET state but only active when RESET is high. MR input includes internal pullup and 100ns glitch immunity without external components.

Key Specifications

Pinout & Package

MAX6324GUT26 is housed in a 6-pin SOT23-6 package (JEDEC MO-178AA), 2.9mm × 1.6mm × 1.1mm, with gull-wing leads and lead-free finish (RoHS-compliant).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6324GUT26, MAX6324GUT29 shifts reset activation upward by 300mV - trading brownout sensitivity for higher noise immunity - while TPS3808G33DBVR eliminates windowed watchdog functionality entirely, reducing diagnostic capability but simplifying layout with push-pull output and no WDPO routing.

Availability

MAX6324GUT26 is available at Aetrix Electronics and suitable for automotive ECU design, industrial PLC development, and medical device manufacturing requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6324GUT26 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 medical applications, with emphasis on reliability and parametric accuracy.

The MAX6324GUT26 belongs to the MAX6323/MAX6324 family of µP supervisory circuits engineered specifically for fail-safe embedded systems requiring dual-threshold watchdog validation and guaranteed reset behavior under extreme voltage and temperature stress.

FAQ

What is the exact reset threshold voltage of MAX6324GUT26 and how is it trimmed?

The MAX6324GUT26 has a nominal reset threshold of 2.70V, with a guaranteed range of 2.63V to 2.77V (±2.5%) over −40°C to +125°C. This value is set by factory laser trimming of on-chip resistors during final test - no external components or calibration are required. The "26" suffix in MAX6324GUT26 directly encodes this 2.70V threshold per Maxim's ordering convention.

Does MAX6324GUT26 support bidirectional µP reset pins, and how is that implemented?

Yes, MAX6324GUT26 supports bidirectional µP reset pins via its open-drain RESET output. When paired with a single external pullup resistor (e.g., 10kΩ), the RESET line can be driven low by either the MAX6324GUT26 or the µP - enabling shared reset arbitration. This is explicitly validated in Maxim's application note for Motorola 68HC11 and other bidirectional-reset microcontrollers.

What are the factory-trimmed watchdog timeout values for MAX6324GUT26?

MAX6324GUT26 uses the "G" fast timeout (29ms min / 39ms max) and "U" slow timeout (82ms min / 108ms max). These values are permanently programmed during wafer sort and cannot be altered in-circuit. The "GUT" portion of the part number confirms this specific dual-window configuration.

Can MAX6324GUT26 operate reliably during cold-cranking when VCC drops below 2.0V?

Yes - MAX6324GUT26 guarantees valid RESET assertion down to VCC = +1.2V, well below typical cold-cranking minimums (~1.8V). Its internal comparators remain functional and sink sufficient current (≥1.2mA at 2.25V) to drive standard CMOS inputs even as supply collapses, making it suitable for ISO 16750-2 automotive qualification.

How does the WDPO output interact with the RESET signal in MAX6324GUT26?

In MAX6324GUT26, WDPO is active only when RESET is high - meaning WDPO pulses low *after* power-up reset completes and the system is running. This decouples fault signaling from startup sequence, preventing spurious WDPO assertions during boot. WDPO remains inactive whenever RESET is asserted (e.g., during brownout or MR activation), ensuring clean separation of power-fault and runtime-fault events.