Analog Devices Inc./Maxim Integrated MAX6865UK32D6S+T

Overview

The MAX6865UK32D6S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, combining voltage monitoring (3.200V reset threshold), manual reset input, and watchdog timer (209s typical timeout) with ultra-low 170nA typical supply current. It asserts an active-high push-pull RESET signal during VCC brownout, MR assertion, or watchdog timeout, ensuring reliable µP initialization in battery-critical systems.

For engineers reviewing the MAX6865UK32D6S+T datasheet, MAX6865UK32D6S+T pinout, MAX6865UK32D6S+T application, or MAX6865UK32D6S+T equivalent, this device supports low-voltage operation down to VCC = 1.1V, offers six factory-trimmed reset timeout options (including 1200ms min), and integrates glitch-immune reset timing for portable medical and handheld electronics.

Technical Context

This IC implements a precision bandgap-based voltage monitor with ±2.5% threshold accuracy over -40°C to +85°C, coupled with a digital watchdog timer that clears on any WDI edge and expires if WDI remains static beyond 209s (typ). The internal reset timeout generator guarantees minimum assertion periods independent of VCC slew rate.

The push-pull active-high RESET output drives directly to VCC with VOH ≥ 0.8×VCC at 500µA source current, while MR features a 10kΩ internal pullup and 1µs minimum pulse width support. Immunity to VCC transients ≤40µs at 100mV overdrive ensures robust operation in noisy power environments.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount. Compact 2.9mm × 1.6mm footprint with 0.95mm height, optimized for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6864UK32D6S+T and TPS3837K32DBVR, the MAX6865UK32D6S+T uniquely delivers both ultra-low 170nA current and integrated 209s watchdog in a pin-compatible active-high push-pull format - essential for long-life, self-recovering portable medical devices.

Availability

MAX6865UK32D6S+T is available at Aetrix Electronics and suitable for portable glucose monitors, patient vital sign loggers, industrial handheld scanners, and smart asset trackers requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for MAX6865UK32D6S+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 industrial, medical, and portable applications.

The MAX6854–MAX6869 family delivers nanopower supervision with integrated watchdog and manual reset - engineered specifically for battery-operated medical wearables and handheld electronics where reliability and multi-year runtime are critical.

FAQ

What is the exact reset threshold voltage of the MAX6865UK32D6S+T?

The MAX6865UK32D6S+T has a factory-trimmed reset threshold of 3.200V, with guaranteed tolerance of ±2.5% over the full -40°C to +85°C operating temperature range. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix '32' corresponds to 3.200V nominal. The MAX6865UK32D6S+T maintains this accuracy without external calibration.

Does the MAX6865UK32D6S+T include a watchdog timer, and what is its timeout period?

Yes, the MAX6865UK32D6S+T includes a watchdog timer with a typical timeout period of 209 seconds, indicated by the 'L' suffix in the part number. This is verified in Table 3 (Watchdog Timeout) and the Ordering Information section, which specifies 'L' for 95s/209s/487s min/typ/max. The timer clears on any rising or falling edge at the WDI pin and expires only if WDI remains static beyond this period.

What type of RESET output does the MAX6865UK32D6S+T provide, and how is it configured?

The MAX6865UK32D6S+T provides an active-high push-pull RESET output, as confirmed in the Pin Description section for MAX6865 and the Selector Guide. Pin 1 drives high during reset assertion and low when deasserted, referenced to VCC, eliminating the need for an external pullup resistor. This configuration is fixed for the MAX6865UK32D6S+T and differs from open-drain or active-low variants in the same family.

What is the minimum VCC voltage at which the MAX6865UK32D6S+T guarantees valid RESET operation?

The MAX6865UK32D6S+T guarantees valid RESET operation down to VCC = 1.1V, as explicitly stated in the Features list and Electrical Characteristics table under "Guaranteed Reset Valid to VCC = +1.1V". This specification ensures reliable reset assertion during deep brownout conditions common in battery-powered systems approaching end-of-life voltage.

How does the manual reset (MR) input function on the MAX6865UK32D6S+T?

The MR input on the MAX6865UK32D6S+T is an active-low signal with an internal 10kΩ pullup to VCC. Driving MR low initiates a reset that remains asserted for the full 1200ms timeout period after MR returns high. The datasheet specifies a 1µs minimum pulse width and 250ns MR-to-reset delay, enabling reliable triggering via momentary switches or logic signals without external debounce circuitry.