Analog Devices Inc./Maxim Integrated MAX6865UK36D5S+T

Overview

The MAX6865UK36D5S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 3.6V reset threshold (±2.5%), 300ms minimum reset timeout, and integrated watchdog timer with 3.3s typical timeout. It monitors VCC, responds to manual reset (MR), and asserts active-high push-pull RESET during brownout, power-up, or watchdog expiration - used in battery-powered glucose monitors and portable medical devices.

For engineers reviewing the MAX6865UK36D5S+T datasheet, MAX6865UK36D5S+T pinout, MAX6865UK36D5S+T application, or MAX6865UK36D5S+T equivalent, this page delivers verified functional identity, exact reset timing behavior, watchdog input (WDI) interface requirements, and validated alternative options for low-power µP supervision in space-constrained, long-life systems.

Technical Context

The MAX6865UK36D5S+T implements a dual-trigger reset architecture: it asserts RESET when VCC falls below 3.6V (±2.5%), when MR is pulled low, or when WDI remains static beyond 3.3s (typ). Its internal watchdog timer clears on any WDI edge and resumes counting only after RESET deasserts.

It guarantees valid RESET output down to VCC = 1.1V, supports CMOS-level MR and WDI inputs (VIH = 0.7×VCC, VIL = 0.3×VCC), and features 250ns MR-to-reset delay and 150ns minimum WDI pulse width detection - enabling robust operation in noisy, low-voltage embedded environments.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, -40°C to +85°C operating range.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6864UK36D5S+T, the MAX6865UK36D5S+T enables direct interface to active-high reset pins without external inversion; versus TPS3836K33DBVR, it delivers 90% lower supply current and adds watchdog supervision - critical for multi-year battery operation and safety-critical firmware recovery.

Availability

MAX6865UK36D5S+T is available at Aetrix Electronics and suitable for glucose monitors, patient vital sign loggers, and wireless medical telemetry units requiring stable component supply, long-lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX6865UK36D5S+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-critical portable medical and handheld electronics - prioritizing nanoscale current draw, factory-trimmed accuracy, and integrated watchdog reliability.

FAQ

What is the exact reset threshold voltage of the MAX6865UK36D5S+T?

The MAX6865UK36D5S+T has a factory-trimmed reset threshold of 3.600V with ±2.5% tolerance over temperature (–40°C to +85°C), corresponding to the "36" suffix in its part number per Maxim's Threshold Suffix Guide. This value is guaranteed across the full operating range and requires no external calibration.

Does the MAX6865UK36D5S+T support active-high or active-low reset output?

The MAX6865UK36D5S+T provides an active-high push-pull RESET output (pin 1), as confirmed by its position in the Selector Guide and Pin Description section for MAX6865. It drives high during reset assertion and low when deasserted - directly compatible with microprocessors requiring active-high reset signaling.

What is the watchdog timeout behavior of the MAX6865UK36D5S+T?

The MAX6865UK36D5S+T features a watchdog timeout period of 3.3s typical (S suffix), with min/max values of 1.5s and 7.75s. The internal timer resets on any rising or falling edge at WDI (pin 4) and resumes counting only after RESET deasserts - ensuring reliable detection of firmware hangs without spurious timeouts.

Can the MAX6865UK36D5S+T operate down to 1.2V supply voltage?

Yes, the MAX6865UK36D5S+T operates across VCC = 1.2V to 5.5V and guarantees valid RESET output down to VCC = 1.1V. At 1.2V, it maintains full functionality including reset assertion, MR input detection, and WDI edge sensing - making it suitable for ultra-low-voltage energy-harvesting or deeply discharged battery systems.

Is the MAX6865UK36D5S+T pin-compatible with other devices in the MAX68xx family?

The MAX6865UK36D5S+T uses the standard 5-pin SOT23-5 package and shares identical pinout (VCC, WDI, MR, GND, RESET) with MAX6864/MAX6866/MAX6867–MAX6869. However, RESET polarity differs: MAX6865 is active-high, while MAX6864 is active-low - requiring schematic review before substitution.