Analog Devices Inc./Maxim Integrated MAX6389XS32D1+T

Overview

MAX6389XS32D1+T from Maxim Integrated is a low-power microprocessor supervisory circuit with open-drain active-low reset output, factory-set 3.20V reset threshold (±2.5% over −40°C to +125°C), 1ms 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 MAX6389XS32D1+T datasheet, MAX6389XS32D1+T pinout, MAX6389XS32D1+T application, or MAX6389XS32D1+T equivalent, key selection criteria include its 4-pin SC70 package, guaranteed reset validity down to VCC = 1V, ±2.5% threshold accuracy across automotive temperature range, and support for user-adjustable secondary voltage monitoring via RESET IN comparator referenced to 1.27V.

Technical Context

The MAX6389XS32D1+T integrates a precision bandgap reference and comparator to monitor VCC against a fixed 3.20V threshold while simultaneously accepting an external voltage at RESET IN for independent monitoring against a 1.27V internal reference. Reset assertion occurs if either voltage falls below its respective threshold, with reset deassertion delayed by a 1ms internal timer after recovery.

Its open-drain RESET output requires an external pullup resistor and guarantees valid logic state down to VCC = 1V; the RESET IN input exhibits ≤50nA leakage and supports resistor-divider configuration for custom thresholds, enabling dual-rail power supervision in compact space-constrained designs.

Key Specifications

Pinout & Package

MAX6389XS32D1+T is housed in a RoHS-compliant 4-pin SC70 package (outline 21-0098, land pattern 90-0187), featuring exposed pad thermal enhancement and JEDEC-standard footprint compatibility.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6389XS32D2+T, MAX6389XS32D1+T reduces boot delay by 19ms-critical for real-time response in industrial control loops-while matching all other electrical and mechanical specifications. Against TPS3808G33DBVR, MAX6389XS32D1+T uniquely delivers integrated dual-rail supervision in the same 4-pin SC70 footprint, eliminating board space and component count penalties.

Availability

MAX6389XS32D1+T is available at Aetrix Electronics and suitable for industrial PLC I/O modules, automotive body control units, medical wearable sensor hubs, and smart energy meter MCU designs requiring stable component supply with AEC-Q100-aligned performance.

Supply support for MAX6389XS32D1+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 computing applications.

The MAX6381–MAX6390 family delivers ultra-low-power, high-accuracy reset supervision for space- and energy-constrained systems, with variants optimized for single/dual-rail monitoring, manual reset, and automotive qualification.

FAQ

What is the exact reset threshold voltage of MAX6389XS32D1+T and how stable is it over temperature?

The MAX6389XS32D1+T has a factory-set nominal reset threshold of 3.20V with ±2.5% tolerance over the full −40°C to +125°C operating range. This stability is achieved through laser-trimmed precision bandgap references and is guaranteed-not typical-across temperature, making MAX6389XS32D1+T suitable for automotive and industrial applications where voltage margin is critical.

Does MAX6389XS32D1+T support monitoring a second voltage rail, and how is it implemented?

Yes, MAX6389XS32D1+T supports dual-rail supervision via its dedicated RESET IN pin, which connects to an internal comparator referenced to 1.27V. By applying a resistor divider between the secondary rail and ground, users can set custom thresholds-for example, a 2.5V rail monitored with R1/R2 = 0.97 yields ~2.5V trip point. MAX6389XS32D1+T asserts reset if either VCC or RESET IN falls below its threshold.

What is the minimum supply voltage at which MAX6389XS32D1+T guarantees correct reset output behavior?

MAX6389XS32D1+T guarantees valid RESET output logic state down to VCC = 1.0V, meaning the open-drain output remains correctly asserted or deasserted even as the supply collapses toward shutdown. This feature ensures deterministic system behavior during brownout recovery and eliminates the need for external pulldown resistors required by many competing supervisors.

What package type and footprint does MAX6389XS32D1+T use, and is it RoHS-compliant?

MAX6389XS32D1+T uses a 4-pin SC70 package (outline 21-0098, land pattern 90-0187) with RoHS-compliant lead-free termination indicated by the "+" suffix. Its 1.3mm × 1.3mm footprint and 0.5mm pitch enable ultra-compact placement in wearables and dense PCB layouts, and the package supports standard reflow soldering profiles up to +260°C.

How does the 1ms reset timeout of MAX6389XS32D1+T compare to alternatives, and when is it appropriate?

The 1ms minimum reset timeout of MAX6389XS32D1+T is the shortest option in the MAX6381–MAX6390 family and is ideal for fast-booting microcontrollers or systems where minimal boot latency is critical-such as real-time industrial controllers. Longer timeouts (e.g., 20ms or 140ms) are better suited for peripherals needing extended stabilization; MAX6389XS32D1+T avoids unnecessary delays without compromising reliability.