Analog Devices Inc./Maxim Integrated MAX6865UK29D5L+T

Overview

The MAX6865UK29D5L+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 2.925V reset threshold, 300ms minimum reset timeout, and 209s typical watchdog timeout. It monitors VCC, responds to manual reset (MR) assertion, and triggers reset on watchdog timer expiration - designed for battery-critical portable medical and handheld electronics.

For engineers reviewing the MAX6865UK29D5L+T datasheet, MAX6865UK29D5L+T pinout, MAX6865UK29D5L+T application, or MAX6865UK29D5L+T equivalent, this page delivers verified functional identity, exact pin roles, confirmed timing parameters, real-world use context, and validated alternative options - all aligned with Maxim's official electrical characteristics and pin configuration data.

Technical Context

This device integrates three core functions: precision voltage monitoring with ±2.5% threshold accuracy over -40°C to +85°C, a manual reset input with 1µs minimum pulse width and 250ns MR-to-reset delay, and a watchdog timer that clears on any WDI edge and expires after 209s (typ) if inactive. The reset output remains asserted for ≥300ms after VCC rises above 2.925V and MR deasserts.

It operates across 1.2V–5.5V supply range, guarantees valid reset down to VCC = 1.1V, and features internal 10kΩ MR pullup. The watchdog timeout exhibits <±20% variation over temperature, and the device is immune to VCC transients ≤40µs at 100mV overdrive - critical for noisy battery-powered environments.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount, footprint-compatible with industry-standard 5-pin SOT23.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6865UK29D5L+T, the S-suffix variant offers faster watchdog response but sacrifices long-idle capability, while TPS3836K33DBVR trades off watchdog safety and ultra-low power for simpler qualification and broader distributor stock - making it viable only in non-safety-critical, short-duration applications.

Availability

MAX6865UK29D5L+T is available at Aetrix Electronics and suitable for portable medical devices, battery-powered diagnostics equipment, and industrial wireless sensors requiring stable component supply across extended production lifecycles.

Supply support for MAX6865UK29D5L+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, sensing, and connectivity in demanding environments.

The MAX6865UK29D5L+T belongs to the MAX68xx nanopower supervisory family, engineered specifically for ultra-long-life battery applications where sub-µA quiescent current, guaranteed reset validity at low VCC, and integrated watchdog safety are mandatory.

FAQ

What is the exact reset threshold voltage of the MAX6865UK29D5L+T?

The MAX6865UK29D5L+T has a factory-trimmed reset threshold voltage of 2.925V, with ±2.5% tolerance over -40°C to +85°C. This value is encoded in the "29" suffix per Maxim's Threshold Suffix Guide (Table 2), and is confirmed in the Electrical Characteristics table under VTH parameter. The MAX6865UK29D5L+T maintains this threshold stability across its full operating temperature range without external calibration.

Does the MAX6865UK29D5L+T include a watchdog timer, and what is its timeout period?

Yes, the MAX6865UK29D5L+T includes a watchdog timer with a typical timeout period of 209 seconds, denoted by the "L" suffix in the part number. This is verified in Table 3 (Watchdog Timeout) and the Ordering Information section. The timer clears on any rising or falling edge at the WDI pin and expires only if WDI remains static beyond 209s (typ), making it suitable for applications with long firmware idle intervals like patient monitors.

What type of reset output does the MAX6865UK29D5L+T provide, and how is it configured?

The MAX6865UK29D5L+T provides a push-pull active-high reset output, as defined by its MAX6865 designation in the Selector Guide and Pin Description section. Pin 1 is labeled RESET (active-high), meaning it drives high (to VCC) when reset is asserted and low when deasserted - eliminating the need for an external pullup resistor and simplifying interface with µPs requiring active-high reset inputs.

What is the minimum reset timeout period for the MAX6865UK29D5L+T, and how is it selected?

The MAX6865UK29D5L+T has a fixed minimum reset timeout period of 300ms, indicated by the "D5" suffix per Table 4 (Reset Timeout Periods). This value is factory-programmed and cannot be altered externally. The 300ms duration ensures sufficient hold time for microprocessors to complete internal power-on reset sequences before release, and is guaranteed across temperature and voltage variations.

Is the MAX6865UK29D5L+T compatible with 1.8V systems, and what is its lowest valid VCC for reset assertion?

Yes, the MAX6865UK29D5L+T operates from 1.2V to 5.5V and is fully specified at 1.8V, with 170nA typical supply current and guaranteed reset functionality down to VCC = 1.1V. This is explicitly stated in the Absolute Maximum Ratings and Electrical Characteristics tables. The MAX6865UK29D5L+T remains fully operational and asserts valid reset even as the supply collapses through the 1.2V–1.1V range - essential for Li-ion battery end-of-discharge behavior.