Analog Devices Inc./Maxim Integrated MAX6865UK16D1L+T

Overview

The MAX6865UK16D1L+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 1.575V reset threshold, 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 MAX6865UK16D1L+T datasheet, MAX6865UK16D1L+T pinout, MAX6865UK16D1L+T application, or MAX6865UK16D1L+T equivalent, key selection criteria include its guaranteed reset validity down to VCC = +1.1V, immunity to short VCC transients (<40µs at 100mV overdrive), pin-selectable reset delay capability (not applicable to this variant), and compatibility with low-voltage µP reset inputs requiring active-high logic.

Technical Context

The MAX6865UK16D1L+T implements a voltage-monitoring comparator with 2.5% threshold accuracy, a digital watchdog timer that clears on any WDI edge and expires if WDI remains static beyond 209s (typ), and an internal 10kΩ MR pullup. Its reset assertion logic combines three independent triggers: VCC falling below 1.575V, MR pulled low, or watchdog timeout - all resulting in active-high RESET assertion for ≥10ms after recovery.

This device belongs to the MAX6864–MAX6869 series with fixed D1 (10ms) reset timeout and L-suffix (209s typ) watchdog period. Unlike CT-enabled variants (e.g., MAX6861–MAX6863), it lacks pin-selectable timing; unlike MAX6854/MAX6855, it includes both MR and WDI inputs and uses active-high push-pull RESET output referenced to VCC.

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 MAX6864UK16D1L+T, the MAX6865UK16D1L+T's active-high RESET eliminates need for external inverters in modern µP designs; versus TPS3836K33DBVR, it delivers 20× lower supply current and integrated watchdog - critical for medical-grade reliability and multi-year battery operation.

Availability

MAX6865UK16D1L+T is available at Aetrix Electronics and suitable for portable medical devices, battery-powered industrial scanners, and low-power wireless sensor nodes requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX6865UK16D1L+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 MAX6865UK16D1L+T belongs to the MAX6864–MAX6869 nanopower supervisory family, engineered specifically for ultra-low-power, safety-critical portable electronics where extended battery life and robust firmware supervision are mandatory.

FAQ

What is the reset threshold voltage of the MAX6865UK16D1L+T?

The MAX6865UK16D1L+T has a factory-trimmed reset threshold voltage of +1.575V, with ±2.5% tolerance over temperature (-40°C to +85°C). This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix '16' corresponds to 1.575V. The threshold remains stable across voltage and temperature, enabling reliable brownout detection in 1.8V systems.

Does the MAX6865UK16D1L+T support active-low or active-high reset output?

The MAX6865UK16D1L+T provides an active-high push-pull RESET output, as specified in its pin description and Selector Guide. Pin 1 asserts high during reset conditions (VCC < 1.575V, MR low, or WDI timeout) and returns low after the 10ms timeout. This differs from the MAX6864UK16D1L+T, which offers active-low output - confirming MAX6865UK16D1L+T's suitability for µPs requiring high-active reset signaling.

What is the watchdog timeout period for the MAX6865UK16D1L+T?

The MAX6865UK16D1L+T features a watchdog timeout period of 209s typical (L-suffix), with min/max values of 95s and 487s respectively. This is explicitly defined in Table 3 (Watchdog Timeout) and confirmed in the Ordering Information section, where 'L' follows the reset timeout code 'D1'. The timer clears on any WDI edge and expires only if WDI remains static beyond this period.

Can the reset timeout period of the MAX6865UK16D1L+T be adjusted externally?

No, the MAX6865UK16D1L+T has a fixed 10ms minimum reset timeout period (D1 option), as indicated by the 'D1' in its part number. Unlike MAX6861–MAX6863 variants with CT pin for selecting between 10ms/150ms, the MAX6865UK16D1L+T does not include a CT input and offers no user-adjustable timing. The timeout is internally set and cannot be modified with external components.

Is the MAX6865UK16D1L+T compatible with 1.2V supply rails?

Yes, the MAX6865UK16D1L+T operates across VCC = 1.2V to 5.5V and guarantees valid reset assertion down to VCC = +1.1V. Its 1.575V threshold is fully functional at 1.2V supply because the internal reference and comparator architecture remain active and accurate at this voltage - confirmed in the Absolute Maximum Ratings and Electrical Characteristics tables under TA = -40°C to +85°C conditions.