Analog Devices Inc./Maxim Integrated MAX6394US445D2+T

Overview

The MAX6394US445D2+T from Maxim Integrated is a low-power CMOS microprocessor supervisory circuit that monitors VCC supply voltage and provides a debounced manual reset input. It features a factory-trimmed 4.45V reset threshold, 14ms minimum reset timeout period, ±1.0% threshold accuracy over -40°C to +125°C, open-drain RESET output capable of being pulled up above VCC, and consumes only 5µA typical supply current. It is used in battery-powered equipment and critical μP power monitoring systems.

For engineers reviewing the MAX6394US445D2+T datasheet, MAX6394US445D2+T pinout, MAX6394US445D2+T application, or MAX6394US445D2+T equivalent, key selection criteria include reset threshold tolerance, timeout period stability over temperature, MR input glitch immunity, open-drain level-shifting capability, and AEC-Q100 qualification status for automotive-grade designs.

Technical Context

The MAX6394US445D2+T implements a precision voltage-monitoring comparator with laser-trimmed internal resistive divider to set its 4.45V reset threshold, and an internal monostable timer that enforces a minimum 14ms reset pulse width after VCC recovery or MR deassertion. Its reset assertion logic is fully static-no external timing components required.

It uses an open-drain n-channel MOSFET for RESET output, enabling level-shifted reset signaling across supply domains (e.g., 3.3V monitored rail driving 5V reset line), and includes an internal 63kΩ pullup on MR to support momentary switch interfacing without external components.

Key Specifications

Pinout & Package

SOT143-4 (4-pin plastic surface-mount package, 1.3mm × 2.9mm footprint, 0.95mm height), JEDEC MO-178 compatible, RoHS-compliant, tape-and-reel packaging (2.5k units per reel).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV803EB29DBZR and MAX6369UT29D2+T, the MAX6394US445D2+T uniquely combines 4.45V precision threshold, MR input with internal pullup, open-drain level-shifting, and AEC-Q100 qualification - making it optimal for automotive and high-reliability portable instrumentation where voltage margin and reset timing certainty are critical.

Availability

MAX6394US445D2+T is available at Aetrix Electronics and suitable for portable medical monitors, automotive body control modules, and industrial PLC I/O modules requiring stable component supply, long-term lifecycle support, and AEC-Q100–compliant alternatives.

Supply support for MAX6394US445D2+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 industrial, automotive, communications, and computing applications.

The MAX6394 belongs to Maxim's high-accuracy μP supervisory product line, engineered specifically for systems demanding guaranteed reset behavior during power-up, brownout, and manual intervention - especially where supply voltage margins are tight and temperature extremes challenge threshold stability.

FAQ

What is the exact reset threshold voltage of the MAX6394US445D2+T?

The MAX6394US445D2+T has a factory-trimmed nominal reset threshold of 4.45V, with ±1.0% accuracy over the full -40°C to +125°C operating temperature range. At +25°C, the tolerance tightens to ±0.6%, yielding a typical range of 4.423V to 4.477V. This value is laser-trimmed during production and does not require external calibration.

Does the MAX6394US445D2+T support manual reset functionality?

Yes, the MAX6394US445D2+T includes a dedicated MR (manual reset) input on Pin 3. A logic-low pulse ≥1µs on MR forces RESET low immediately and holds it for the full 14ms timeout period after MR returns high. An internal 63kΩ pullup resistor allows MR to be left floating if unused, eliminating the need for external components in basic implementations.

Can the RESET output of the MAX6394US445D2+T be pulled up to a voltage higher than VCC?

Yes, the MAX6394US445D2+T features an open-drain RESET output rated for voltages up to +6.0V, independent of VCC. This allows the RESET signal to interface with higher-voltage logic domains (e.g., pulling RESET to 5V while monitoring a 3.3V VCC rail), enabling level-shifted reset coordination without additional translators.

What is the minimum reset timeout period specified for the MAX6394US445D2+T?

The MAX6394US445D2+T is configured with the D2 timeout option, specifying a minimum reset timeout period of 14ms. Typical and maximum values are 28ms and 40ms respectively, all guaranteed over -40°C to +125°C. This interval begins when VCC rises above 4.45V or when MR is deasserted, ensuring sufficient time for microprocessor core and peripheral stabilization.

Is the MAX6394US445D2+T qualified for automotive applications?

The base MAX6394US445D2+T is rated for -40°C to +125°C operation and meets AEC-Q100 requirements when ordered with the /V suffix (e.g., MAX6394US445D2/V+T). While the +T suffix indicates tape-and-reel packaging, the /V variant adds automotive qualification testing - including stress tests for temperature cycling, humidity, and ESD - making it suitable for body electronics and infotainment systems.