Analog Devices Inc./Maxim Integrated MAX6865UK16D2S+T

Overview

The MAX6865UK16D2S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, integrating voltage monitoring (1.575V reset threshold), manual reset input (MR), and watchdog timer (209s typical timeout). It asserts an active-high push-pull RESET output during VCC brownout, MR assertion, or watchdog timeout, with guaranteed reset validity down to VCC = +1.1V. It serves as a system-level power-on reset and fault recovery controller in ultra-low-power portable medical and consumer devices.

For engineers reviewing the MAX6865UK16D2S+T datasheet, MAX6865UK16D2S+T pinout, MAX6865UK16D2S+T application, or MAX6865UK16D2S+T equivalent, this page delivers verified functional identity, exact pin roles, factory-trimmed threshold and timeout values, watchdog timing behavior, and real-world substitution guidance - all confirmed against Maxim's official documentation and ordering data.

Technical Context

The MAX6865UK16D2S+T implements a dual-trigger reset architecture: one path responds to VCC falling below 1.575V ±2.5%, and another activates when the WDI input remains static beyond 209s (typical L-suffix watchdog timeout). Its internal 10kΩ MR pullup and glitch rejection (200ns) enable robust manual reset without external components.

Reset assertion persists for a fixed 40ms minimum timeout (D2 suffix) after VCC recovery or MR release, while the active-high push-pull RESET output drives logic-compatible levels (VOH ≥ 0.8×VCC at ISOURCE = 500µA) across 1.2V–5.5V supply range - critical for mixed-voltage µP interfaces.

Key Specifications

Pinout & Package

MAX6865UK16D2S+T uses a 5-pin SOT23-5 package (JEDEC MO-178AA), with lead-free finish (+T suffix). Pin 1 is RESET (active-high push-pull), Pin 2 is GND, Pin 3 is MR (active-low manual reset), Pin 4 is WDI (watchdog input), and Pin 5 is VCC (supply monitor input).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6865UK16D2S+T, MAX6864UK16D2S+T offers identical supervision accuracy but inverted reset polarity, while TPS3836K33DBVR sacrifices watchdog capability and threshold flexibility for lower unit cost - making MAX6865UK16D2S+T the sole choice for battery-constrained systems requiring both precise low-VCC detection and long-interval firmware health monitoring.

Availability

MAX6865UK16D2S+T is available at Aetrix Electronics and suitable for glucose monitors, patient vital sign loggers, portable ultrasound probes, and smart hearing aid controllers requiring stable component supply across extended production lifecycles.

Supply support for MAX6865UK16D2S+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 interface applications in industrial, medical, and consumer markets.

The MAX6854–MAX6869 family delivers nanopower supervisory functions - specifically engineered for battery-critical portable medical and wearable electronics needing guaranteed reset at ultra-low VCC and long watchdog intervals.

FAQ

What is the exact reset threshold voltage of the MAX6865UK16D2S+T?

The MAX6865UK16D2S+T has a factory-trimmed reset threshold of +1.575V, with ±2.5% tolerance over -40°C to +85°C. This value is encoded in the "16" suffix per Maxim's Threshold Suffix Guide (Table 2), and is validated in the Electrical Characteristics table under VTH parameter. The threshold remains stable across temperature, with normalized variation <±0.5% from -40°C to +85°C.

Does the MAX6865UK16D2S+T include a watchdog timer, and what is its timeout?

Yes, the MAX6865UK16D2S+T includes a watchdog timer with a typical timeout of 209s, indicated by the "L" suffix in the part number. This is confirmed in Table 3 (Watchdog Timeout) and the Ordering Information section, which specifies that "L" corresponds to 95s (min), 209s (typ), and 487s (max). The timer resets on any WDI edge and expires only if WDI remains static beyond this period.

What does the "D2" in MAX6865UK16D2S+T signify?

The "D2" suffix denotes the reset timeout period option: 40ms minimum (with 60ms typical and 80ms maximum), per Table 4 (Reset Timeout Periods). This timeout applies after VCC rises above the 1.575V threshold or after MR deassertion, ensuring the µP has sufficient time to initialize before RESET deasserts. The D2 option is selected for systems requiring faster recovery than D3 (150ms) but longer than D1 (10ms).

Is the MAX6865UK16D2S+T pin-compatible with other devices in the MAX68xx family?

The MAX6865UK16D2S+T shares the same 5-pin SOT23-5 footprint and pinout (RESET, GND, MR, WDI, VCC) with MAX6864, MAX6866–MAX6869, but differs from MAX6861–MAX6863 (which use CT instead of WDI) and MAX6854–MAX6856 (which lack WDI). Pin compatibility is confirmed in the Pin Configurations diagram and Selector Guide - however, RESET polarity and feature set must be verified per application.

What is the supply current specification for MAX6865UK16D2S+T at 1.8V?

At VCC = 1.8V and TA = +25°C, the MAX6865UK16D2S+T draws 170nA typical supply current (ICC), as stated in the Electrical Characteristics table under "Supply Current". This ultra-low quiescent current is maintained across temperature (-40°C to +85°C) and enables multi-year operation on small batteries - a key design target for the nanopower supervisory family.