Analog Devices Inc./Maxim Integrated MAX6865UK38D1L+T

Overview

MAX6865UK38D1L+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 3.800V reset threshold (±2.5%), 10ms minimum reset timeout, and integrated watchdog timer with 209s 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 MAX6865UK38D1L+T datasheet, MAX6865UK38D1L+T pinout, MAX6865UK38D1L+T application, or MAX6865UK38D1L+T equivalent, this page delivers verified functional identity, exact pin roles, confirmed timing parameters, real-world use cases, and validated alternative parts for low-power µP reset and watchdog supervision.

Technical Context

The MAX6865UK38D1L+T implements a precision bandgap-based voltage monitor with 2.5% threshold tolerance over –40°C to +85°C, coupled with a digital watchdog timer that clears on any WDI edge and expires if WDI remains static >209s (typ). Its internal MR pullup (10kΩ) and guaranteed RESET validity down to VCC = 1.1V enable robust operation in deep-brownout conditions.

This device belongs to the MAX6864–MAX6869 variant group with active-high push-pull RESET output, manual reset input (MR), and watchdog input (WDI). It uses BiCMOS process (2848 transistors), supports no external components, and is immune to VCC transients ≤40µs at 100mV overdrive.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6865UK38D1L+T, the S-suffix variant trades long watchdog interval for faster fault response, while TPS3836K33DBVR sacrifices watchdog capability and nanopower operation for cost-sensitive, non-battery-critical designs - neither offers pin-to-pin compatibility or identical feature set.

Availability

MAX6865UK38D1L+T is available at Aetrix Electronics and suitable for portable medical devices, industrial wireless sensors, handheld diagnostic tools, and battery-powered data loggers requiring stable component supply across extended product lifecycles.

Supply support for MAX6865UK38D1L+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 demanding industrial, medical, and automotive environments.

The MAX6864–MAX6869 family was engineered specifically for ultra-low-power microprocessor supervision in battery-constrained systems, integrating voltage monitoring, manual reset, and configurable watchdog functionality in minimal 5-pin SOT23 packaging.

FAQ

What is the exact reset threshold voltage of MAX6865UK38D1L+T?

The MAX6865UK38D1L+T has a factory-trimmed reset threshold of 3.800V with ±2.5% tolerance over –40°C to +85°C, as defined by the "38" suffix in its part number per Maxim's Threshold Suffix Guide (Table 2). This value is measured at VCC falling and guarantees reliable detection of brownout conditions on 3.3V/3.6V rails.

Does MAX6865UK38D1L+T support active-high or active-low reset output?

MAX6865UK38D1L+T provides an active-high push-pull RESET output (pin 1), meaning it drives the output high during reset assertion and low during deassertion. This configuration eliminates the need for an external pullup resistor and directly interfaces with µPs requiring high-active reset inputs, such as many ARM Cortex-M and PIC microcontrollers.

What is the watchdog timeout period for MAX6865UK38D1L+T?

The MAX6865UK38D1L+T features a watchdog timeout period of 209s typical (minimum 95s, maximum 487s), indicated by the "L" suffix in its part number. The timer resets on any rising or falling edge at the WDI pin and expires only if WDI remains static beyond this interval, making it ideal for low-duty-cycle sensor applications.

Can MAX6865UK38D1L+T operate below 1.8V supply voltage?

Yes, MAX6865UK38D1L+T operates from VCC = 1.2V to 5.5V and guarantees valid RESET output down to VCC = 1.1V. At 1.2V, its supply current is 190nA typical, enabling functionality in deeply discharged lithium coin cells or energy-harvesting systems where supply voltage may dip near 1.2V during peak load.

Is MAX6865UK38D1L+T pin-compatible with other MAX68xx supervisory devices?

MAX6865UK38D1L+T shares the same 5-pin SOT23-5 pinout as all MAX6864–MAX6869 variants (pins: 1=RESET, 2=GND, 3=MR, 4=WDI, 5=VCC), but is not pin-compatible with MAX6854–MAX6863 families due to differing pin 4 function (CT vs. WDI) and RESET polarity variations. Always verify pin mapping against the specific variant's Pin Description table.