Analog Devices Inc./Maxim Integrated MAX6389XS29D2-T

Overview

The MAX6389XS29D2-T from Maxim Integrated is a low-power microprocessor supervisory circuit with open-drain active-low reset output, factory-set 2.93V reset threshold (±2.5% over -40°C to +125°C), 20ms 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 battery-powered embedded systems requiring reliable power-on reset and brownout protection.

For engineers reviewing the MAX6389XS29D2-T datasheet, MAX6389XS29D2-T pinout, MAX6389XS29D2-T application, or MAX6389XS29D2-T equivalent, key selection criteria include its 2.93V V_TH, 20ms t_RP, open-drain output requiring external pullup, RESET IN comparator referenced to +1.27V, and guaranteed valid reset state down to V_CC = 1V.

Technical Context

This device implements a precision voltage comparator monitoring V_CC against a factory-trimmed 2.93V threshold and a separate high-impedance RESET IN input compared to an internal +1.27V reference. Reset assertion occurs when either voltage falls below its respective threshold, and the open-drain output remains low for ≥20ms after recovery.

The internal timer guarantees reset timeout accuracy across temperature (-40°C to +125°C) with ±2.5% threshold tolerance and 60ppm/°C tempco. Its 3μA supply current at 1.8V and operation down to V_CC = 1V enable use in ultra-low-power applications where supply rail collapse must be detected before logic failure.

Key Specifications

Pinout & Package

MAX6389XS29D2-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, suitable for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6389XS29D2-T, the MAX6389XS29D3-T offers longer reset assertion for slower power supplies, while TLV803EB29DBZR trades dual-supervision capability for smaller footprint and push-pull simplicity in single-rail designs.

Availability

MAX6389XS29D2-T is available at Aetrix Electronics and suitable for portable medical sensors, automotive body control modules, industrial PLC I/O cards, and smart home hub power management requiring stable component supply and long-term lifecycle support.

Supply support for MAX6389XS29D2-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 communications applications.

The MAX6381–MAX6390 family delivers ultra-low-power, high-accuracy reset supervision for battery-operated and multi-rail embedded systems, emphasizing factory-trimmed thresholds, wide temperature operation, and flexible reset output configurations.

FAQ

What is the exact reset threshold voltage of the MAX6389XS29D2-T?

The MAX6389XS29D2-T has a factory-set reset threshold of 2.93V, with guaranteed accuracy of ±2.5% over the full operating temperature range of -40°C to +125°C. This value is fixed per the "29" suffix in the part number and applies to the V_CC input; the RESET IN input compares against a separate +1.27V internal reference.

Does the MAX6389XS29D2-T support monitoring of a second voltage rail?

Yes, the MAX6389XS29D2-T supports dual-voltage supervision via its dedicated RESET IN pin. This high-impedance input is compared to an internal +1.27V reference, allowing users to set a custom reset threshold for a second rail using an external resistor divider. Reset asserts if either V_CC falls below 2.93V or the voltage at RESET IN drops below +1.27V.

What type of reset output does the MAX6389XS29D2-T provide, and what are its drive requirements?

The MAX6389XS29D2-T features an open-drain active-low reset output. It requires an external pullup resistor to a logic rail (typically V_CC or another compatible voltage). The output can sink up to 3.2mA when V_CC ≥ 4.5V, 1.2mA at V_CC ≥ 2.5V, or 80μA at V_CC ≥ 1.0V, with VOL ≤ 0.4V under those conditions.

What is the minimum supply voltage at which the MAX6389XS29D2-T guarantees correct reset output behavior?

The MAX6389XS29D2-T guarantees valid reset output logic state down to V_CC = 1.0V. Below this voltage, the internal circuitry may not function reliably, but the device remains operational and correctly asserts reset as V_CC falls through the 2.93V threshold, even during deep brownout conditions.

How does the MAX6389XS29D2-T handle short-duration voltage transients on the V_CC rail?

The MAX6389XS29D2-T incorporates built-in immunity to negative-going V_CC transients. It rejects glitches up to 100mV below the 2.93V threshold if their duration is ≤1µs, preventing false resets caused by electrical noise or switching spikes. Adding a 0.1µF capacitor close to the V_CC pin further enhances transient suppression.