Analog Devices Inc./Maxim Integrated MAX6389XS29D3-T

Overview

MAX6389XS29D3-T from Maxim Integrated is a low-power microprocessor supervisory circuit with open-drain active-low reset output, factory-set 2.93V VCC reset threshold (±2.5% over -40°C to +125°C), 140ms minimum reset timeout, and auxiliary RESET IN input for dual-voltage monitoring. It operates from 1.0V to 5.5V supply and consumes only 3μA at 1.8V, targeting power-critical embedded systems requiring reliable brownout detection.

For engineers reviewing the MAX6389XS29D3-T datasheet, MAX6389XS29D3-T pinout, MAX6389XS29D3-T application, or MAX6389XS29D3-T equivalent, key selection considerations include its 2.93V reset threshold accuracy, 140ms VCC reset timeout, open-drain output requiring external pullup, RESET IN comparator referenced to 1.27V, and 4-pin SC70 package compatibility with space-constrained designs.

Technical Context

The MAX6389XS29D3-T integrates a precision voltage comparator for VCC monitoring and a separate high-impedance RESET IN comparator referenced to an internal 1.27V bandgap. Reset assertion occurs when either VCC falls below 2.93V or RESET IN drops below its threshold (set via external resistor divider), with guaranteed reset state validity down to VCC = 1V.

Its timing architecture uses a temperature-stable internal oscillator to generate the 140ms minimum reset timeout period after VCC recovery or RESET IN recovery. The open-drain RESET output supports wired-OR configurations and level-shifting, while the RESET IN input draws only ±1nA leakage current, enabling high-impedance sensing of secondary supplies.

Key Specifications

Pinout & Package

MAX6389XS29D3-T is housed in a RoHS-compliant 4-pin SC70 package (outline 21-0098, land pattern 90-0187), measuring 2.0mm × 2.1mm × 0.95mm, optimized for high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6389LT29D3-T, the MAX6389XS29D3-T offers identical supervision functionality in a smaller 4-pin SC70 footprint ideal for space-constrained designs, while TLV809E29DBZR provides a lower-cost alternative when dual-supply monitoring is unnecessary.

Availability

MAX6389XS29D3-T is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, medical wearable sensor hubs, and smart energy meters requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MAX6389XS29D3-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 and mixed-signal ICs for industrial, automotive, and computing applications, emphasizing low power, high reliability, and small form factors.

The MAX6381–MAX6390 family delivers ultra-low-power microprocessor supervisory circuits with configurable reset thresholds and timeouts, specifically engineered for battery-powered and thermally constrained embedded systems demanding robust power-fail detection.

FAQ

What is the exact reset threshold voltage of the MAX6389XS29D3-T?

The MAX6389XS29D3-T has a factory-set VCC reset threshold of 2.93V nominal, with guaranteed accuracy of ±2.5% over the full operating temperature range (-40°C to +125°C). This value is fixed and not adjustable; the "29" suffix in the part number explicitly denotes the 2.93V threshold per Maxim's ordering guide.

Does the MAX6389XS29D3-T support monitoring a second voltage rail?

Yes, the MAX6389XS29D3-T includes a dedicated RESET IN input pin that compares an external voltage against an internal 1.27V reference. When the voltage at RESET IN falls below this threshold, the device asserts reset - enabling independent monitoring of a secondary supply such as an I/O rail or sensor bias voltage alongside the primary VCC rail.

What is the function of the open-drain RESET output on the MAX6389XS29D3-T?

The open-drain RESET output on the MAX6389XS29D3-T requires an external pullup resistor to a logic rail (e.g., 3.3V or 5V). It actively pulls low during reset assertion and floats high otherwise, allowing multiple devices to share a common reset bus (wired-OR configuration) and supporting level translation between different voltage domains in mixed-supply systems.

What is the minimum reset timeout period specified for the MAX6389XS29D3-T?

The MAX6389XS29D3-T has a minimum reset timeout period of 140ms after VCC rises above the 2.93V threshold or after the RESET IN signal recovers. This guaranteed minimum ensures sufficient time for microprocessor initialization, clock stabilization, and peripheral configuration before release of the reset signal.

Is the MAX6389XS29D3-T qualified for automotive applications?

No, the MAX6389XS29D3-T is not automotive-qualified. Its ordering code lacks the "/V" suffix required for AEC-Q100 qualification. For automotive use, select variants such as MAX6389XS29D3/V+T, which undergo additional stress testing and screening to meet automotive reliability standards.