Analog Devices Inc./Maxim Integrated MAX6865UK29D5S+T

Overview

The MAX6865UK29D5S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring active-high push-pull reset output, manual reset input (MR), and watchdog timer with 209s typical timeout. It monitors VCC down to +1.1V, asserts reset when supply drops below factory-trimmed 2.925V threshold, and guarantees reset validity during brownout conditions in portable medical and battery-powered systems.

For engineers reviewing the MAX6865UK29D5S+T datasheet, MAX6865UK29D5S+T pinout, MAX6865UK29D5S+T application, or MAX6865UK29D5S+T equivalent, this device supports low-power system initialization, fault recovery, and software execution monitoring where ultra-low 170nA supply current, precise voltage supervision, and watchdog timeout stability across temperature are critical selection criteria.

Technical Context

The MAX6865UK29D5S+T implements a dual-trigger reset architecture: one path responds to VCC falling below 2.925V ±2.5%, and another activates when the watchdog input (WDI) remains static beyond 209s (typ). Its internal timer enforces a fixed 600ms minimum reset timeout after VCC recovery or WDI activity.

It uses BiCMOS process technology for nanoscale leakage control, features MR internally pulled up to VCC via 10kΩ, and provides guaranteed RESET assertion down to VCC = +1.1V - enabling reliable operation during deep brownouts in glucose monitors and handheld diagnostics.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount. Compact footprint (2.9mm × 1.6mm × 1.1mm) 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 MAX6865UK29D5S+T, the MAX6865UK29D5L+T offers faster watchdog response but sacrifices long-duration hang detection, while TPS3837K33DBVR omits watchdog entirely and increases power consumption - making MAX6865UK29D5S+T uniquely balanced for ultra-low-power, watchdog-dependent medical and portable systems.

Availability

MAX6865UK29D5S+T is available at Aetrix Electronics and suitable for portable medical devices, battery-powered diagnostics, and low-power IoT edge nodes requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for MAX6865UK29D5S+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 demanding industrial, medical, and communications applications.

The MAX6865UK29D5S+T belongs to the MAX6854–MAX6869 nanopower supervisory family, engineered specifically for battery-critical systems requiring guaranteed reset behavior, ultra-low current, and integrated watchdog protection without external components.

FAQ

What is the exact reset threshold voltage of the MAX6865UK29D5S+T?

The MAX6865UK29D5S+T has a factory-trimmed reset threshold voltage of +2.925V, with tolerance of ±2.5% over the full operating temperature range (-40°C to +85°C). This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "29" corresponds to 2.925V nominal. The MAX6865UK29D5S+T maintains this accuracy without external calibration components.

Does the MAX6865UK29D5S+T support active-high or active-low reset output?

The MAX6865UK29D5S+T provides an active-high push-pull reset output (RESET pin), as confirmed in the Pin Description section for MAX6865 and the Selector Guide. When reset is asserted, RESET goes high; when deasserted, it returns low. This matches µP reset inputs requiring active-high logic, eliminating external level-shifting circuitry. The MAX6865UK29D5S+T does not offer open-drain or active-low variants.

What is the watchdog timeout period for the MAX6865UK29D5S+T?

The MAX6865UK29D5S+T features a watchdog timeout period of 209s typical (L suffix), with min/max values of 95s and 487s over temperature and process variation. This is specified in Table 3 (Watchdog Timeout) and confirmed in the Ordering Information, where "S" denotes 3.3s and "L" denotes 209s. The MAX6865UK29D5S+T uses the L option, making it suitable for detecting extended firmware hangs in infrequently updated embedded systems.

Can the MAX6865UK29D5S+T operate with supply voltages below 1.8V?

Yes, the MAX6865UK29D5S+T operates from VCC = 1.2V to 5.5V and guarantees valid reset assertion down to VCC = +1.1V, as stated in the Absolute Maximum Ratings and Electrical Characteristics tables. At 1.2V, its supply current remains ultra-low (190nA typ), and RESET output retains defined logic levels per VOL/VOH specs. This enables reliable supervision of sub-1.8V logic rails in modern ultra-low-power SoCs - a key capability of the MAX6865UK29D5S+T.

Is the MAX6865UK29D5S+T pin-compatible with other devices in the MAX68xx family?

The MAX6865UK29D5S+T shares the same 5-pin SOT23-5 package and pinout (RESET, GND, MR, WDI, VCC) with MAX6864, MAX6866, MAX6867, MAX6868, and MAX6869, as shown in the Pin Configurations diagram and Selector Guide. However, it is not pin-compatible with MAX6861–MAX6863 (which use CT instead of WDI) or MAX6854–MAX6856 (which lack WDI). Direct substitution is only valid among the MAX6864–MAX6869 group with matching reset output polarity and timeout options.