Analog Devices Inc./Maxim Integrated MAX6324AUT46+

Overview

MAX6324AUT46+ from Maxim Integrated is a microprocessor supervisory circuit with windowed (min/max) watchdog, open-drain RESET output, and factory-trimmed 4.63V reset threshold (±2.5% accuracy) and fast/slow timeout windows (A-suffix: 719ms fast / 1.5s slow). It guarantees valid RESET down to VCC = +1.2V and draws only 23µA typical supply current. Used in automotive engine control units to detect firmware hang or clock fault during cold-crank conditions.

For engineers reviewing the MAX6324AUT46+ datasheet, MAX6324AUT46+ pinout, MAX6324AUT46+ application, or MAX6324AUT46+ equivalent, key selection criteria include its open-drain RESET compatibility with bidirectional µP reset pins, guaranteed 100ms reset timeout after VCC recovery, 1ms WDPO pulse width on watchdog fault, and operation across -40°C to +125°C for under-hood deployment.

Technical Context

The MAX6324AUT46+ implements a dual-window watchdog that detects both fast faults (WDI falling edges <719ms apart) and slow faults (no WDI edge >1.5s), independent of the VCC monitor. Its internal BiCMOS comparator ensures ±2.5% reset threshold accuracy over temperature, with RESET asserted low when VCC drops below 4.63V or MR is pulled low.

WDPO is an open-drain output pulsed low for exactly 1ms upon fault detection, while RESET remains open-drain with guaranteed deassertion delay ≥100ms after VCC rises above threshold and MR releases. The device requires no external components for basic operation beyond a 500pF VCC bypass capacitor.

Key Specifications

Pinout & Package

MAX6324AUT46+ is housed in a 6-pin SOT23 package (outline U6-1, land pattern 90-0175), RoHS-compliant and lead-free per "+" suffix.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6324AUT46+, MAX6324AUT44+ offers identical timing behavior but targets a lower nominal supply, while TLV809E46DBZR reduces cost and complexity at the expense of missing critical min/max watchdog fault detection required in automotive and industrial control.

Availability

MAX6324AUT46+ is available at Aetrix Electronics and suitable for automotive engine control, industrial PLC CPU modules, and medical infusion pump controllers requiring stable component supply across extended temperature and long product lifecycles.

Supply support for MAX6324AUT46+ 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.

The MAX6323/MAX6324 family delivers robust µP supervision with windowed watchdogs specifically for safety-critical embedded systems where timing integrity is non-negotiable.

FAQ

What is the exact reset threshold voltage of MAX6324AUT46+ and how accurate is it?

The MAX6324AUT46+ has a factory-laser-trimmed reset threshold of 4.63V with ±2.5% accuracy over -40°C to +125°C. This value is confirmed in the Reset Threshold Range table (page 11) and Electrical Characteristics (page 2), ensuring reliable detection of brownout on +5.0V rails without calibration or external components. The MAX6324AUT46+ achieves this via on-chip trimming during final test.

Does MAX6324AUT46+ support interfacing with microcontrollers that have bidirectional reset pins?

Yes, the MAX6324AUT46+ features an open-drain RESET output, enabling direct connection to bidirectional µP reset pins (e.g., Motorola 68HC11) using a single pullup resistor. This configuration allows either the MAX6324AUT46+ or the µP to assert reset, supporting flexible system-level fault recovery. The MAX6324AUT46+ datasheet explicitly confirms this capability in Applications Information (page 8, Figure 7).

What are the watchdog timeout periods configured for MAX6324AUT46+?

The "A" suffix in MAX6324AUT46+ selects the fastest watchdog window: 719ms maximum for fast faults and 1.5s minimum for slow faults. These values are specified in the Watchdog Timeout table (page 1) and verified in Electrical Characteristics (page 3, tWD1/tWD2 rows for AUT_ _). The MAX6324AUT46+ uses laser-trimming to achieve this precision without external timing components.

Can MAX6324AUT46+ operate reliably during severe supply voltage droop?

Yes, the MAX6324AUT46+ guarantees valid RESET output down to VCC = +1.2V, as stated in the General Description and Electrical Characteristics (page 2). Below this voltage, the internal circuitry ceases sinking current-but the MAX6324AUT46+ ensures deterministic behavior through the full operational range, critical for controlled shutdown in automotive cold-crank scenarios.

Is MAX6324AUT46+ qualified for automotive applications?

The MAX6324AUT46+ is not explicitly marked with "/V" (automotive qualification suffix) in its ordering code, and the datasheet does not list AEC-Q100 qualification for this specific variant. While it operates across -40°C to +125°C and meets many automotive environmental requirements, formal automotive qualification requires the /V-suffixed version (e.g., MAX6324AUT46+/V+T). Always verify qualification status via Maxim/Analog Devices' official product change notices for MAX6324AUT46+.