Analog Devices Inc./Maxim Integrated MAX6865UK31D5S+T

Overview

The MAX6865UK31D5S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, a factory-trimmed 3.075V reset threshold (suffix "31"), 600ms minimum reset timeout (suffix "D5"), and integrated watchdog timer with 3.3s typical timeout (suffix "S"). It monitors VCC, responds to manual reset (MR), and triggers reset on watchdog expiration - designed for battery-critical portable medical and handheld electronics.

For engineers reviewing the MAX6865UK31D5S+T datasheet, MAX6865UK31D5S+T pinout, MAX6865UK31D5S+T application, or MAX6865UK31D5S+T equivalent, this page delivers verified circuit role, exact reset timing, watchdog behavior, pin-level interface details, and validated alternative options - all confirmed against Maxim's official datasheet Rev 4 (12/2005) and ordering documentation.

Technical Context

The MAX6865UK31D5S+T implements a dual-trigger reset architecture: it asserts reset when VCC falls below 3.075V (±2.5%), when MR is pulled low, or when the watchdog input (WDI) remains static beyond 3.3s (typ). Its internal timer guarantees reset remains active for ≥600ms after VCC recovery and MR deassertion.

It uses BiCMOS process technology (2848 transistors), supports operation down to VCC = 1.1V with guaranteed RESET validity, and features 200ns MR glitch rejection and 150ns WDI pulse detection - enabling robust operation in noisy, low-voltage embedded systems.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free (indicated by "+T" suffix), footprint-compatible with industry-standard 5-lead SOT23 layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6864UK31D5S+T, the MAX6865UK31D5S+T provides active-high RESET compatibility without external inversion; versus TPS3837K33DBVR, it delivers 10× lower supply current and integrated watchdog - critical for clinical-grade portable devices.

Availability

MAX6865UK31D5S+T is available at Aetrix Electronics and suitable for portable glucose monitors, patient vital sign loggers, industrial handheld scanners, and smart medical pens requiring stable component supply across long production lifecycles.

Supply support for MAX6865UK31D5S+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, medical, and communications applications.

The MAX6854–MAX6869 family was engineered specifically for ultra-low-power microprocessor supervision in battery-constrained medical and portable electronics - prioritizing nanoscale current, wide VCC range, and reliable watchdog timing.

FAQ

What is the exact reset threshold voltage of the MAX6865UK31D5S+T?

The MAX6865UK31D5S+T has a factory-trimmed reset threshold voltage of 3.075V, with ±2.5% tolerance over temperature (−40°C to +85°C), as defined by the "31" suffix in its part number and confirmed in Table 2 of the Maxim datasheet Rev 4.

Does the MAX6865UK31D5S+T include a watchdog timer, and what is its timeout?

Yes, the MAX6865UK31D5S+T includes a watchdog timer with a typical timeout of 3.3s (minimum 1.5s, maximum 7.75s), indicated by the "S" suffix. The timer resets on any rising or falling edge at the WDI pin and triggers reset if no edge occurs within the timeout window.

What type of RESET output does the MAX6865UK31D5S+T provide?

The MAX6865UK31D5S+T provides an active-high push-pull RESET output (pin 1), meaning it drives high during reset assertion and low when deasserted - eliminating the need for an external pullup resistor and simplifying interface to standard µP reset inputs.

What is the minimum reset timeout period for the MAX6865UK31D5S+T?

The MAX6865UK31D5S+T has a minimum reset timeout period of 600ms, specified by the "D5" suffix. This ensures the reset signal remains asserted for at least 600ms after VCC rises above 3.075V and MR is deasserted, allowing sufficient time for µP initialization.

Can the MAX6865UK31D5S+T operate reliably at very low supply voltages?

Yes, the MAX6865UK31D5S+T guarantees valid RESET output functionality down to VCC = 1.1V, enabling safe and deterministic reset behavior during deep brownout conditions common in aging or low-temperature battery operation.