Analog Devices Inc./Maxim Integrated MAX6324EUT31-T

Overview

MAX6324EUT31-T from Maxim Integrated is an open-drain microprocessor supervisory circuit with windowed (min/max) watchdog timer, 3.08V ±2.5% reset threshold, and guaranteed RESET assertion down to VCC = +1.2V. It monitors power supply integrity and µP activity in automotive and industrial control systems, asserting RESET on undervoltage or manual reset, and pulsing WDPO on fast/slow watchdog faults.

For engineers reviewing the MAX6324EUT31-T datasheet, MAX6324EUT31-T pinout, MAX6324EUT31-T application, or MAX6324EUT31-T equivalent, key selection criteria include its factory-trimmed 15ms fast / 300ms slow watchdog timeout window (suffix 'E'), 3.08V reset threshold (suffix '31'), SOT23-6 open-drain output architecture, and AEC-Q100-compatible operation across –40°C to +125°C.

Technical Context

The MAX6324EUT31-T implements a dual-window watchdog that detects both premature (faster than 15ms) and delayed (slower than 300ms) falling edges on WDI, triggering a 1ms open-drain WDPO pulse. Its reset comparator guarantees valid low-level RESET output even as VCC decays to +1.2V, enabling robust brownout detection in noisy environments.

It features debounced MR input with internal 50–85kΩ pullup, 23µA typical supply current at 3.3V, and operates from 1.2V to 5.5V. The device uses laser-trimmed thresholds and timeouts - no external components required for timing or voltage setting.

Key Specifications

Pinout & Package

MAX6324EUT31-T is housed in a 6-pin SOT23 package (outline 21-0058, land pattern 90-0175), with thermal resistance θJA = 115°C/W on multilayer board. Pin functions are validated per Maxim's official pin description table and typical operating circuit.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6324EUT31-T, MAX6324EUT29-T offers identical timing and form factor but shifts reset threshold downward for tighter 3.0V rail margining, while TPS3808G33DBVR trades windowed watchdog intelligence for lower cost and push-pull simplicity - making it suitable only where fast/slow fault differentiation is unnecessary.

Availability

MAX6324EUT31-T is available at Aetrix Electronics and suitable for automotive engine control units, industrial PLC modules, medical infusion pump controllers, and smart grid communication nodes requiring stable component supply across extended temperature and long product lifecycles.

Supply support for MAX6324EUT31-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 MAX6324 series belongs to Maxim's µP supervisory product line, engineered specifically for high-reliability embedded systems requiring simultaneous voltage monitoring, manual reset, and intelligent windowed watchdog supervision - with emphasis on AEC-Q100 compliance and extended temperature operation.

FAQ

What is the exact reset threshold voltage of MAX6324EUT31-T?

The MAX6324EUT31-T has a nominal reset threshold of 3.08V, with guaranteed minimum and maximum values of 3.00V and 3.15V respectively (±2.5% accuracy over –40°C to +125°C). This threshold is laser-trimmed at wafer test and applies to the specific '31' suffix variant of the MAX6324 family. The MAX6324EUT31-T uses this precise value to assert RESET reliably during 3.3V system brownout conditions.

Does MAX6324EUT31-T support windowed watchdog functionality, and what are its timeout values?

Yes, MAX6324EUT31-T implements a true windowed (min/max) watchdog: fast timeout is 15ms (min), slow timeout is 300ms (min), with typical values of 15ms and 450ms respectively. These values correspond to the 'E' suffix in the part number and are factory-laser-trimmed - no external components needed. The MAX6324EUT31-T triggers WDPO on either premature or delayed WDI falling edges relative to this window.

What is the output type of the RESET pin on MAX6324EUT31-T, and how should it be interfaced?

The RESET output of MAX6324EUT31-T is open-drain, requiring an external pullup resistor to a valid logic-high voltage (up to +6V). This architecture enables bidirectional reset bus sharing (e.g., with Motorola 68HC11) and level-shifting across supply domains. Unlike the push-pull MAX6323 variant, the MAX6324EUT31-T's open-drain RESET must never be left floating - a 10kΩ pullup is typical for most 3.3V or 5V applications.

Can MAX6324EUT31-T operate down to 1.2V supply, and what happens to RESET below that?

Yes, MAX6324EUT31-T guarantees valid RESET output down to VCC = +1.2V - meaning it will actively sink current and hold RESET low until VCC drops below this point. Below +1.2V, the internal output stage ceases sinking capability, and RESET becomes high-impedance. This behavior is explicitly characterized and ensures predictable failure mode during deep brownout, a key requirement for MAX6324EUT31-T in safety-critical automotive and medical systems.

What is the watchdog input (WDI) pulse requirement for MAX6324EUT31-T?

The WDI input of MAX6324EUT31-T requires a minimum falling-edge pulse width of 300ns and is designed to reject transients shorter than 100ns. It is edge-triggered (falling edge only), and the internal watchdog timer resets on each valid falling edge within the 15ms/300ms window. The MAX6324EUT31-T ignores all WDI activity while RESET or WDPO is asserted, and the first WDI falling edge after RESET deassertion is ignored for fast-fault detection to prevent false triggers.