Analog Devices Inc./Maxim Integrated MAX6390XS31D4+T

Overview

MAX6390XS31D4+T from Maxim Integrated is a low-power microprocessor supervisory circuit with open-drain active-low reset output, factory-set 3.08V VCC reset threshold (±2.5% over –40°C to +125°C), 1120ms minimum VCC reset timeout, and 140ms minimum manual reset timeout. It monitors single-supply systems in battery-powered instrumentation and embedded controllers where reliable power-up/down sequencing and noise-immune reset assertion are critical.

For engineers reviewing the MAX6390XS31D4+T datasheet, MAX6390XS31D4+T pinout, MAX6390XS31D4+T application, or MAX6390XS31D4+T equivalent, key selection considerations include its 3μA supply current at 1.8V, guaranteed reset validity down to VCC = 1V, 1.56kΩ internal MR pullup resistor, and SC70-4 package compatibility with space-constrained PCB layouts.

Technical Context

The MAX6390XS31D4+T implements a precision bandgap-based voltage comparator for VCC monitoring and a dedicated manual reset input (MR) with fast 200ns MR-to-reset delay. Its open-drain RESET output requires an external pullup and guarantees correct logic state down to VCC = 1V, enabling robust reset signaling even during deep brownout conditions.

It features dual timeout architecture: a longer 1120ms VCC reset timeout ensures stable processor initialization after slow-rising supplies, while a shorter 140ms manual reset timeout supports rapid operator-triggered recovery. The device exhibits ±60ppm/°C reset threshold tempco and rejects negative-going VCC transients up to 35µs at 100mV overdrive.

Key Specifications

Pinout & Package

MAX6390XS31D4+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. This compact footprint supports high-density PCB layouts in portable and space-constrained designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326XR31D4+T and TPS3808G33DBVR, MAX6390XS31D4+T uniquely combines open-drain flexibility, integrated strong MR pullup, and matched VCC/MR timeout ratios-making it optimal for cost-sensitive, space-constrained designs needing both automatic and manual reset assurance without external components.

Availability

MAX6390XS31D4+T is available at Aetrix Electronics and suitable for battery-powered instrumentation, industrial controller power sequencing, automotive body control modules, and medical point-of-care devices requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6390XS31D4+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 power management, sensing, and interface applications in industrial, automotive, and computing markets.

The MAX6381–MAX6390 family delivers ultra-low-power, high-accuracy reset supervision for microprocessor-based systems where supply stability, temperature resilience, and minimal board area are design priorities.

FAQ

What is the exact reset threshold voltage of MAX6390XS31D4+T?

The MAX6390XS31D4+T has a factory-set VCC reset threshold of 3.08V nominal, with guaranteed limits of 3.00V (min) and 3.15V (max) at +25°C. Over the full operating temperature range (–40°C to +125°C), the threshold maintains ±2.5% accuracy relative to the nominal value, ensuring consistent trip points in automotive and industrial environments where MAX6390XS31D4+T is deployed.

Does MAX6390XS31D4+T support manual reset functionality?

Yes, MAX6390XS31D4+T includes a dedicated active-low manual reset input (MR) with an internal 1.56kΩ pullup resistor to VCC. Driving MR low forces reset assertion for the duration of the low pulse plus a guaranteed 140ms minimum timeout after release. This eliminates external pullup components and provides noise-immune operator or test-system initiated reset capability-key for field service and diagnostics in systems using MAX6390XS31D4+T.

What package type and dimensions does MAX6390XS31D4+T use?

MAX6390XS31D4+T is supplied in a lead-free, RoHS-compliant 4-pin SC70 package (outline number 21-0098), measuring 2.0mm × 2.1mm × 0.95mm. Its compact footprint and thermal resistance (θJA = 322.6°C/W on multilayer board) make it ideal for space-constrained PCBs in portable equipment where MAX6390XS31D4+T provides reliable reset supervision without compromising layout density.

How does the reset timeout behavior differ between VCC and MR events for MAX6390XS31D4+T?

MAX6390XS31D4+T implements asymmetric timeout periods: a 1120ms minimum timeout for VCC-induced resets ensures robust hold-off during slow-rising power supplies, while a shorter 140ms minimum timeout applies to manual reset (MR) events-enabling rapid recovery from user-triggered resets. This dual-timing architecture is intrinsic to MAX6390XS31D4+T and avoids the need for external timing components or firmware workarounds.

Is MAX6390XS31D4+T compatible with 1.8V I/O systems?

Yes, MAX6390XS31D4+T guarantees correct reset output logic state down to VCC = 1V and operates with supply voltages from 1.0V to 5.5V. Its open-drain RESET output can interface directly with 1.8V I/O domains using a 1.8V pullup resistor, and its 3μA supply current at 1.8V makes it ideal for ultra-low-power 1.8V microcontroller systems where MAX6390XS31D4+T delivers precise, energy-efficient supervision.