Analog Devices Inc./Maxim Integrated MAX6865UK43D6L+T

Overview

The MAX6865UK43D6L+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, combining voltage monitoring, manual reset input (MR), and watchdog timer (WDI) functionality. It asserts an active-high push-pull RESET output when V_CC drops below 4.300V (typ), MR is pulled low, or the watchdog times out after 209s (typ). Designed for ultra-low-power systems, it draws only 170nA (typ) supply current and guarantees valid reset operation down to V_CC = +1.1V - ideal for glucose monitors and battery-powered medical devices.

For engineers reviewing the MAX6865UK43D6L+T datasheet, MAX6865UK43D6L+T pinout, MAX6865UK43D6L+T application, or MAX6865UK43D6L+T equivalent, key selection criteria include its factory-trimmed 4.300V reset threshold, 1200ms minimum reset timeout (D6), L-suffix 209s watchdog period, active-high push-pull RESET output, and guaranteed operation at V_CC ≥ 1.1V in portable healthcare and industrial edge sensors.

Technical Context

This device implements a dual-trigger reset architecture: one path responds to V_CC falling below the 4.300V threshold (±2.5%), and another activates on MR assertion or WDI inactivity exceeding 209s (typ). The internal watchdog timer clears on any WDI edge (rising or falling) and remains disabled while RESET is asserted.

The reset timeout is fixed at 600–1200ms (D6 option), with deassertion delayed until V_CC exceeds V_TH + 150mV and MR is released. Its push-pull active-high RESET output sources ≥500µA at V_CC ≥ 2.38V and maintains VOH ≥ 0.8×V_CC, eliminating external pullups.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free (RoHS-compliant), 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 MAX6865UK43D6L+T, MAX6864UK43D6L+T offers identical supervision accuracy and timing but requires µP-level logic inversion, while TPS3838K33DBVR trades nanopower operation and watchdog capability for lower unit cost in simpler power-monitoring roles.

Availability

MAX6865UK43D6L+T is available at Aetrix Electronics and suitable for glucose monitors, patient monitoring systems, industrial wireless sensors, and smart energy meters requiring stable component supply across extended product lifecycles.

Supply support for MAX6865UK43D6L+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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, medical, and communications applications.

The MAX6854–MAX6869 family was designed specifically for ultra-low-power microprocessor supervision in battery-critical portable medical and IoT edge devices, integrating precision voltage monitoring, manual reset, and configurable watchdog functionality in minimal footprint.

FAQ

What is the exact reset threshold voltage of the MAX6865UK43D6L+T?

The MAX6865UK43D6L+T has a factory-trimmed reset threshold of 4.300V (typical), 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 "43" corresponds to V_TH = 4.193V (min) to 4.408V (max), centered at 4.300V. The MAX6865UK43D6L+T uses this precise threshold to supervise 4.5V nominal rails in medical and industrial systems.

Does the MAX6865UK43D6L+T include a watchdog timer, and what is its timeout period?

Yes, the MAX6865UK43D6L+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 95–487s range (typ 209s). The MAX6865UK43D6L+T watchdog clears on any WDI edge and expires only if WDI remains static longer than this period - critical for detecting firmware hangs in long-cycle applications.

What does the "D6" in MAX6865UK43D6L+T signify?

The "D6" suffix in MAX6865UK43D6L+T specifies the reset timeout period option: 600–1200ms (minimum 600ms, typical 900ms, maximum 1200ms), per Table 4 (Reset Timeout Periods). This fixed delay ensures the host microprocessor completes power-up initialization before RESET deasserts. The MAX6865UK43D6L+T uses this D6 timing to meet stringent reset-hold requirements in safety-critical medical devices.

Is the RESET output of the MAX6865UK43D6L+T active-high or active-low?

The MAX6865UK43D6L+T features an active-high push-pull RESET output, as confirmed in the Pin Description section for MAX6865 (page 8) and the Selector Guide (page 16). When asserted, RESET drives high; when deasserted, it drives low. This eliminates the need for an external pullup resistor and simplifies interface to µPs with active-high reset inputs. The MAX6865UK43D6L+T differs from MAX6864 (active-low) and MAX6866 (open-drain) variants in this key interface behavior.

What package type and environmental compliance does the MAX6865UK43D6L+T use?

The MAX6865UK43D6L+T is supplied in a 5-pin SOT23-5 package with lead-free (RoHS-compliant) termination, indicated by the "+T" suffix per Maxim's ordering conventions. This matches the standard SOT23 footprint used across the MAX6854–MAX6869 family and is compatible with automated PCB assembly processes. The MAX6865UK43D6L+T operates across –40°C to +85°C and meets JEDEC moisture sensitivity level MSL-1, enabling reliable deployment in demanding industrial and medical environments.