Analog Devices Inc./Maxim Integrated MAX6324HUT23+

Overview

MAX6324HUT23+ from Maxim Integrated is a windowed watchdog supervisory IC for microprocessor systems, featuring open-drain RESET output, ±2.5% accurate 2.32V reset threshold, 719ms/1.3s factory-trimmed watchdog timeout (H variant), and guaranteed operation down to VCC = +1.2V. It monitors power integrity and processor timing in automotive engine control units and industrial PLCs.

For engineers reviewing the MAX6324HUT23+ datasheet, MAX6324HUT23+ pinout, MAX6324HUT23+ application, or MAX6324HUT23+ equivalent, key selection criteria include its AEC-Q100-qualified automotive grade, SOT23-6 package, min/max watchdog fault detection, manual reset debouncing, and open-drain compatibility with bidirectional μP reset pins.

Technical Context

The MAX6324HUT23+ implements a dual-threshold (min/max) watchdog architecture that detects both fast faults (WDI falling edges <719ms apart) and slow faults (no WDI edge >1.3s), with WDPO pulsed low for 1ms on fault detection. Its internal reset comparator guarantees valid RESET assertion down to VCC = +1.2V, enabling robust brownout recovery in noisy automotive environments.

It uses laser-trimmed thresholds for precision: nominal reset voltage is 2.32V (±2.5%), and watchdog timeouts are fixed at 719ms (fast) and 1.3s (slow) per the "H" suffix. The device operates across -40°C to +125°C and draws only 23µA typical supply current, supporting low-power embedded monitoring.

Key Specifications

Pinout & Package

MAX6324HUT23+ is housed in a 6-pin SOT23 package (package code U6-1), footprint-compatible with industry-standard 6-lead SOT-23 layouts and suitable for high-density automotive PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6324HUT44+ and TPS3808G33DBVR, the MAX6324HUT23+ uniquely delivers AEC-Q100-qualified min/max watchdog supervision at 2.32V with guaranteed sub-1.2V reset validity-making it the only option for safety-critical low-voltage automotive and medical applications requiring deterministic fault coverage.

Availability

MAX6324HUT23+ 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 under AEC-Q100 compliance and extended temperature operation.

Supply support for MAX6324HUT23+ 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 automotive, industrial, and communications markets, with emphasis on reliability and signal integrity.

The MAX6323/MAX6324 product line delivers microprocessor supervisory circuits with windowed watchdog functionality, targeting safety-critical embedded systems where both fast and slow software faults must be independently detected and reported.

FAQ

What is the exact reset threshold voltage of MAX6324HUT23+ and how is it trimmed?

The MAX6324HUT23+ has a nominal reset threshold of 2.32V with ±2.5% accuracy over –40°C to +125°C. This value is achieved via factory laser trimming of on-chip resistors, eliminating the need for external calibration components and ensuring consistent performance across production lots without user adjustment.

Does MAX6324HUT23+ support both fast and slow watchdog fault detection, and what are the exact timeout values?

Yes, the MAX6324HUT23+ implements true min/max (windowed) watchdog functionality. For the "H" suffix variant, the fast timeout is 719ms (minimum interval between WDI falling edges), and the slow timeout is 1.3s (maximum allowable interval). These values are factory-trimmed and fixed-no external components or configuration are required.

Can MAX6324HUT23+ operate reliably when VCC drops below 2.0V, and what happens to the RESET output?

Yes, MAX6324HUT23+ guarantees functional RESET assertion down to VCC = +1.2V. Below this voltage, the internal circuitry ceases sinking current and RESET becomes high-impedance. However, above +1.2V-including at 1.8V or 2.0V-the open-drain RESET output remains fully operational and will assert low as expected during brownout events.

Is MAX6324HUT23+ qualified for automotive applications, and what certification does it hold?

Yes, MAX6324HUT23+ is AEC-Q100 qualified (Grade 0: –40°C to +125°C), with full stress testing including HTOL, TC, and ESD per automotive standards. The "/V" designation in related variants (e.g., MAX6324HUT44/V+T) confirms automotive qualification; MAX6324HUT23+ shares the same die and qualification-only the reset threshold differs.

How does the manual reset (MR) input behave on MAX6324HUT23+, and does it require an external pullup?

The MR input on MAX6324HUT23+ is internally pulled up to VCC and debounced, so no external pullup or RC network is needed. A momentary low pulse ≥1µs asserts RESET and clears the watchdog timer. When unused, MR may be left floating or tied to VCC-no additional components are required for basic operation.