Analog Devices Inc./Maxim Integrated MAX6865UK20D2L+T

Overview

The MAX6865UK20D2L+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, integrating voltage monitoring (2.000V 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 expiration, 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 MAX6865UK20D2L+T datasheet, MAX6865UK20D2L+T pinout, MAX6865UK20D2L+T application, or MAX6865UK20D2L+T equivalent, key selection criteria include its 2.000V factory-trimmed threshold, 40ms minimum reset timeout, 209s watchdog period, active-high push-pull output, and operation across –40°C to +85°C with 170nA typical supply current.

Technical Context

This device implements a dual-monitoring architecture: a precision bandgap-based voltage detector triggers reset when VCC falls below 2.000V ±2.5%, while a digital watchdog timer monitors WDI transitions and expires if no edge occurs within 209s (typ). The internal reset timeout generator enforces a fixed 40ms (D2) deassertion delay after VCC recovery or MR release.

The MR input features 10kΩ internal pullup and 1µs minimum pulse width support; WDI accepts CMOS-compatible levels and detects edges as short as 150ns. RESET output is push-pull active-high, referenced to VCC, with VOH ≥0.8×VCC at ISOURCE = 500µA and VOL ≤0.3V at ISINK = 1.2mA.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, surface-mount, lead-free (+T suffix), 2.9mm × 1.6mm footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6864UK20D2L+T, the MAX6865UK20D2L+T adds active-high push-pull output compatibility with newer µPs, while differing from TPS3837MPW20DBVR by enabling long-interval firmware supervision and cutting supply current by >99%-critical for multi-year battery operation.

Availability

MAX6865UK20D2L+T is available at Aetrix Electronics and suitable for glucose monitors, patient monitoring devices, smart wearables, and industrial sensor nodes requiring stable component supply, long-term lifecycle support, and lead-free compliance.

Supply support for MAX6865UK20D2L+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 MAX6865UK20D2L+T belongs to the MAX68xx nanopower supervisory family, engineered specifically for ultra-low-power portable medical and battery-operated consumer electronics requiring guaranteed reset integrity and long-duration watchdog supervision.

FAQ

What is the exact reset threshold voltage of the MAX6865UK20D2L+T?

The MAX6865UK20D2L+T has a factory-trimmed reset threshold of 2.000V 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 "20" corresponds to 2.000V nominal. The MAX6865UK20D2L+T maintains this accuracy without external calibration components.

Does the MAX6865UK20D2L+T support active-high or active-low reset output?

The MAX6865UK20D2L+T provides an active-high push-pull RESET output, as confirmed in the Pin Description section for MAX6865 (page 8) and Selector Guide (page 16). Unlike open-drain or active-low variants, this version drives the RESET pin high during fault conditions and requires no external pullup resistor.

What is the watchdog timeout period for the MAX6865UK20D2L+T?

The MAX6865UK20D2L+T features a watchdog timeout period of 209s (typical), indicated by the "L" suffix in its part number. This is verified in Table 3 (Watchdog Timeout) and applies across the full operating temperature range. The watchdog clears on any WDI edge and expires only if no transition occurs within this interval.

What is the minimum reset timeout duration of the MAX6865UK20D2L+T?

The MAX6865UK20D2L+T has a minimum reset timeout duration of 40ms, specified by the "D2" suffix per Table 4 (Reset Timeout Periods). This ensures the RESET signal remains asserted for at least 40ms after VCC rises above 2.000V or MR is released, satisfying boot timing requirements of most modern microcontrollers.

Is the MAX6865UK20D2L+T compatible with 1.8V supply systems?

Yes, the MAX6865UK20D2L+T operates with VCC from 1.2V to 5.5V and guarantees RESET validity down to VCC = +1.1V. Its 170nA typical supply current at VCC = 1.8V (per Electrical Characteristics table) and 2.000V threshold make it fully compatible with 1.8V logic domains and low-voltage battery systems.