Analog Devices Inc./Maxim Integrated MAX6865UK22D6L+T

Overview

MAX6865UK22D6L+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 2.235V reset threshold (suffix '22'), 1200ms minimum reset timeout (D6), and 209s typical watchdog timeout (L). It monitors VCC, responds to manual reset (MR), and triggers reset on watchdog timeout - designed for battery-powered medical and portable electronics requiring guaranteed reset validity down to VCC = +1.1V.

For engineers reviewing the MAX6865UK22D6L+T datasheet, MAX6865UK22D6L+T pinout, MAX6865UK22D6L+T application, or MAX6865UK22D6L+T equivalent, this page delivers verified functional identity, exact pin roles, real-world timing behavior, and validated alternative options - all confirmed against Maxim's official datasheet Rev 4 (12/05) and ordering documentation.

Technical Context

The MAX6865UK22D6L+T implements a dual-trigger reset architecture: it asserts reset when VCC falls below 2.235V, when MR is pulled low, or when WDI remains static beyond 209s (typ). Its internal watchdog timer clears on any WDI edge, MR assertion, or active reset - enabling robust software execution monitoring without false timeouts.

Reset deassertion follows a fixed 1200ms (min) timeout after VCC rises above threshold *and* MR is released. The device guarantees valid reset output down to VCC = +1.1V and rejects VCC transients ≤40µs at 100mV overdrive - critical for noisy, low-voltage battery systems.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free (RoHS-compliant), -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 TPS3836K33DBVR and MAX6361KA29D3+T, the MAX6865UK22D6L+T uniquely combines nanopower operation, programmable watchdog supervision, and precise 2.235V threshold - making it irreplaceable in long-life, safety-aware portable medical designs.

Availability

MAX6865UK22D6L+T is available at Aetrix Electronics and suitable for portable medical devices, low-power IoT sensors, industrial handheld terminals, and wearable health trackers requiring stable component supply across extended production lifecycles.

Supply support for MAX6865UK22D6L+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 delivers nanopower supervisory functions - specifically engineered for battery-constrained systems needing guaranteed reset behavior, manual recovery, and watchdog-based firmware integrity assurance.

FAQ

What is the exact reset threshold voltage of MAX6865UK22D6L+T?

The MAX6865UK22D6L+T has a factory-trimmed reset threshold of 2.235V, with ±2.5% tolerance over temperature. This value is defined by the '22' suffix per Maxim's Threshold Suffix Guide (Table 2), and is confirmed in the Electrical Characteristics table under VTH. The device guarantees reset assertion when VCC falls below this threshold and remains asserted until VCC exceeds it and the 1200ms timeout expires.

Does MAX6865UK22D6L+T support active-high or active-low reset output?

The MAX6865UK22D6L+T features an active-high push-pull reset output (pin 1). When reset is asserted, RESET goes high; when deasserted, it returns low. This is confirmed in the MAX6865-specific Pin Description (page 8) and Selector Guide (page 16), which lists MAX6865 under "Push-Pull ACTIVE HIGH" with MR and WDI enabled.

What is the watchdog timeout behavior of MAX6865UK22D6L+T?

The MAX6865UK22D6L+T provides a typical watchdog timeout of 209s (L suffix), with min/max of 95s/487s. The internal timer clears on any WDI edge, MR assertion, or active reset - ensuring it only times out during true firmware hangs. It does not require periodic high-low toggling; a single edge suffices to reset the timer, as documented in the Detailed Description section (page 11).

Can MAX6865UK22D6L+T operate reliably below 1.8V?

Yes - the MAX6865UK22D6L+T operates from VCC = 1.2V to 5.5V and guarantees valid reset output down to VCC = +1.1V. Its 170nA typical supply current and 2.235V threshold make it suitable for 1.8V and 2.5V systems, and its performance is characterized at 1.8V in the Electrical Characteristics table (ICC = 170nA typ, VOL ≤0.3V at ISINK = 500µA).

Is MAX6865UK22D6L+T pin-compatible with other MAX68xx supervisory ICs?

The MAX6865UK22D6L+T uses the standard 5-pin SOT23-5 footprint shared across the MAX6854–MAX6869 family, but pin function differs by variant. Specifically, MAX6865 has WDI on pin 4 and RESET (active-high) on pin 1 - matching MAX6865/MAX6868 pinout (page 15), not MAX6864/MAX6866. Direct replacement requires verifying MR, WDI, and RESET polarity alignment in the target design.