Analog Devices Inc./Maxim Integrated MAX6324HUT23+T

Overview

MAX6324HUT23+T from Maxim Integrated is a microprocessor supervisory IC with windowed (min/max) watchdog, open-drain RESET output, and factory-trimmed 2.32V reset threshold (±2.5% accuracy). It monitors VCC down to +1.2V, asserts RESET for ≥100ms after power recovery, and delivers 1ms WDPO fault pulses on fast/slow watchdog timeouts. Used in automotive engine control units to detect firmware hangs during cold-cranking.

For engineers reviewing the MAX6324HUT23+T datasheet, MAX6324HUT23+T pinout, MAX6324HUT23+T application, or MAX6324HUT23+T equivalent, key selection criteria include its AEC-Q100-qualified operation over –40°C to +125°C, SOT23-6 package, 23µA typical supply current, and guaranteed RESET validity at VCC = +1.2V - critical for low-voltage brownout resilience in safety-critical embedded systems.

Technical Context

The MAX6324HUT23+T implements a dual-window watchdog that detects both fast faults (WDI falling edges <719ms apart) and slow faults (no WDI edge >1.3s), with WDPO pulsed low for 1ms per fault. Its reset comparator guarantees valid output down to VCC = +1.2V, enabling reliable reset assertion during deep brownouts.

It uses laser-trimmed thresholds: nominal reset voltage is 2.32V (UT23 suffix), and watchdog timeout is set to H-window (719ms fast / 1.3s slow). The open-drain RESET output requires an external pullup and supports level-shifting across supply domains, while MR input includes internal 50–85kΩ pullup and 100ns glitch immunity.

Key Specifications

Pinout & Package

MAX6324HUT23+T is housed in a 6-pin SOT23 package (package code U6+1A, outline 21-0058), rated for 696mW dissipation at TA = +70°C with 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 MAX6324HUT23/V+T, the MAX6324HUT23+T offers identical core functionality but lacks formal AEC-Q100 certification documentation - making it ideal for pre-qualification design phases. Against TPS3808G33DBVR, it provides superior fault coverage via windowed watchdog and lower quiescent current, justifying its use in safety-aware systems despite higher unit cost.

Availability

MAX6324HUT23+T is available at Aetrix Electronics and suitable for automotive engine control, industrial PLC I/O modules, and medical infusion pump controllers requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MAX6324HUT23+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 AEC-Q100-qualified µP supervisory circuits with windowed watchdog capability, targeting safety-critical embedded systems where deterministic fault detection and robust power monitoring are mandatory.

FAQ

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

The MAX6324HUT23+T has a nominal reset threshold of 2.32V with ±2.5% accuracy over –40°C to +125°C. This value is laser-trimmed at wafer sort and verified per device; the UT23 suffix explicitly denotes the 2.25V–2.38V threshold range. No external components are required to achieve this precision, eliminating calibration overhead in production.

Does MAX6324HUT23+T support watchdog functionality for both fast and slow timing violations?

Yes, MAX6324HUT23+T implements a true windowed (min/max) watchdog. With the H-suffix, it detects fast faults when WDI falling edges occur less than 719ms apart, and slow faults when no WDI edge is observed for more than 1.3s. WDPO pulses low for 1ms in either case, providing unambiguous hardware-level fault indication independent of the RESET signal.

Can MAX6324HUT23+T operate reliably when VCC drops below 2.0V?

Yes, MAX6324HUT23+T guarantees valid RESET output down to VCC = +1.2V - confirmed in Electrical Characteristics table and Typical Operating Characteristics plots. Below +1.2V, the open-drain RESET output ceases sinking current, but above that threshold, reset assertion remains fully functional, enabling robust brownout response in automotive and industrial environments.

What is the purpose of the MR pin on MAX6324HUT23+T and how should it be used?

The MR (manual reset) pin on MAX6324HUT23+T is an active-low input that forces RESET assertion and clears the watchdog timer when pulled low ≥1µs. It features an internal 50–85kΩ pullup, so it may be left floating if unused. For external triggering, connect directly to a switch or logic output - no external pullup or debounce circuitry is needed due to built-in 100ns glitch immunity.

How does the WDPO output behave during RESET assertion on MAX6324HUT23+T?

On MAX6324HUT23+T, WDPO is disabled (high-impedance) whenever RESET is asserted. WDPO only becomes active - i.e., capable of pulsing low on watchdog faults - after RESET deasserts. This sequencing prevents conflicting signals during power-up or manual reset events and ensures WDPO reflects only runtime firmware health, not power-state transitions.