Analog Devices Inc./Maxim Integrated MAX6324HUT46+T

Overview

MAX6324HUT46+T from Maxim Integrated is a windowed watchdog supervisory IC for microprocessor systems, featuring open-drain RESET output, 4.63V ±2.5% reset threshold, 719ms fast timeout / 1.3s slow timeout (H-suffix), and guaranteed operation down to VCC = +1.2V. It monitors power integrity and software execution timing in automotive engine control units and industrial PLCs.

For engineers reviewing the MAX6324HUT46+T datasheet, MAX6324HUT46+T pinout, MAX6324HUT46+T application, or MAX6324HUT46+T equivalent, key selection criteria include its AEC-Q100-qualified open-drain reset architecture, factory-trimmed dual-window watchdog, and extended temperature support (-40°C to +125°C) for harsh-environment embedded control.

Technical Context

The MAX6324HUT46+T implements a min/max (windowed) watchdog timer with two independent timeout thresholds: tWD1 = 719ms (fast fault detection) and tWD2 = 1.3s (slow fault detection), both laser-trimmed and stable over temperature. Its VCC monitor uses a precision bandgap reference to guarantee ±2.5% accuracy across -40°C to +125°C.

RESET is open-drain and requires an external pullup; WDPO is also open-drain and pulses low for 1ms upon fault detection. The device asserts RESET when VCC drops below 4.63V or MR is pulled low, holding it active for ≥100ms after recovery - critical for reliable µP initialization in automotive brownout conditions.

Key Specifications

Pinout & Package

MAX6324HUT46+T is housed in a 6-pin SOT23 package (package code U6+1A), footprint-compatible with JEDEC MO-178AA, and rated for 115°C/W junction-to-ambient thermal resistance on multilayer PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6324HUT44+T and TLV809E46DBVR, the MAX6324HUT46+T uniquely delivers AEC-Q100-aligned windowed watchdog protection for +5V systems, enabling detection of both early and late software timing faults - a capability absent in single-threshold alternatives and essential for ASIL-B and SIL-2 safety-critical designs.

Availability

MAX6324HUT46+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 and long product lifecycles.

Supply support for MAX6324HUT46+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.

The MAX6323/MAX6324 family delivers precision power supervision and windowed watchdog functionality specifically for safety-critical embedded systems where deterministic reset behavior and software execution validation are mandatory.

FAQ

What is the exact reset threshold voltage of MAX6324HUT46+T and how is it trimmed?

The MAX6324HUT46+T has a nominal reset threshold of 4.63V 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 or adjustment. The "46" suffix in MAX6324HUT46+T explicitly denotes this 4.63V threshold, as confirmed in the Reset Threshold Range table of the official datasheet.

Does MAX6324HUT46+T support windowed watchdog functionality, and what are its timeout values?

Yes, MAX6324HUT46+T implements a true min/max (windowed) watchdog. With the "H" suffix, its fast timeout (tWD1) is 719ms and slow timeout (tWD2) is 1.3s - both factory-laser-trimmed and characterized over temperature. These values define the valid window for WDI falling edges; pulses arriving earlier than 719ms or later than 1.3s trigger a 1ms WDPO pulse.

Is MAX6324HUT46+T qualified for automotive applications?

The base MAX6324HUT46+T is not AEC-Q100 qualified; however, the pin- and function-compatible MAX6324HUT46/V+T variant is fully AEC-Q100 qualified for automotive use. Both share identical electrical specifications, SOT23-6 packaging, and H/46 timing/threshold configuration - only the /V suffix indicates automotive qualification and enhanced reliability screening.

What is the recommended pullup resistor value for the RESET and WDPO outputs of MAX6324HUT46+T?

A 10kΩ pullup resistor is recommended for both RESET and WDPO outputs of MAX6324HUT46+T when interfacing with standard CMOS logic. This value ensures sufficient sink current (≤0.4V at 1.2mA) while minimizing power draw and maintaining noise immunity. For higher supply voltages (up to +6V), verify that the connected logic inputs tolerate the pulled-up voltage level.

Can MAX6324HUT46+T operate reliably during deep brownout conditions?

Yes, MAX6324HUT46+T guarantees functional RESET output down to VCC = +1.2V, as specified in the Electrical Characteristics table. Below this voltage, the internal circuitry ceases to drive RESET, but above +1.2V - including during gradual brownout - RESET remains valid and asserted as needed, ensuring µP enters a known safe state before complete power loss.