Analog Devices Inc./Maxim Integrated MAX6865UK16D1S+T

Overview

The MAX6865UK16D1S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, combining voltage monitoring (1.575V reset threshold), manual reset input (MR), and watchdog timer (3.3s timeout) with ultra-low 170nA typical supply current. It asserts an active-high push-pull RESET signal during VCC brownout, MR assertion, or watchdog timeout, and holds reset for 10ms minimum after recovery - ideal for battery-powered glucose monitors and portable medical devices.

For engineers reviewing the MAX6865UK16D1S+T datasheet, MAX6865UK16D1S+T pinout, MAX6865UK16D1S+T application, or MAX6865UK16D1S+T equivalent, key selection criteria include its 1.575V factory-trimmed reset threshold, 10ms reset timeout, 3.3s watchdog period, active-high push-pull output, and guaranteed reset validity down to VCC = +1.1V.

Technical Context

This device implements a dual-trigger reset architecture: one path monitors VCC against a precision bandgap-derived 1.575V threshold with 2.5% hysteresis, while a second path responds to MR assertion or WDI inactivity exceeding 3.3s (typ). The internal watchdog clears on any WDI edge, MR low, or RESET assertion - preventing false timeouts during software initialization or interrupt handling.

Its push-pull active-high RESET output delivers VOH ≥ 0.8×VCC at ISOURCE = 500µA (VCC ≥ 2.38V) and VOL ≤ 0.3V at ISINK = 1.2mA (VCC ≥ 2.38V), enabling direct interface with 1.8V–5.5V µP reset inputs without external level-shifting. Immunity to sub-40µs VCC transients (at 100mV overdrive) ensures robust operation in noisy portable systems.

Key Specifications

Pinout & Package

Package: 5-pin SOT23 (2.9mm × 1.6mm × 1.1mm), lead-free, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6864UK16D1S+T, the MAX6865UK16D1S+T provides active-high reset polarity essential for modern low-voltage µPs, while TPS3836K33DBVR lacks both the precise 1.575V threshold and watchdog capability critical for medical-grade reliability.

Availability

MAX6865UK16D1S+T is available at Aetrix Electronics and suitable for glucose monitors, patient vital sign recorders, industrial handheld scanners, and smart wearable health trackers requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MAX6865UK16D1S+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, emphasizing low power, high reliability, and integrated functionality.

The MAX6865UK16D1S+T belongs to Maxim's nanopower µP supervisory family, engineered specifically for battery-critical medical and portable electronics where sub-µA current, factory-trimmed thresholds, and dual-trigger (VCC + watchdog) reset assurance are mandatory.

FAQ

What is the exact reset threshold voltage of the MAX6865UK16D1S+T?

The MAX6865UK16D1S+T has a factory-trimmed reset threshold of 1.575V with ±2.5% tolerance over -40°C to +85°C. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "16" corresponds to 1.575V nominal. The device guarantees reset assertion when VCC falls below this threshold and deassertion only after VCC exceeds 1.575V + hysteresis (0.5% of VTH).

Does the MAX6865UK16D1S+T support active-high or active-low reset output?

The MAX6865UK16D1S+T provides an active-high push-pull RESET output, as specified in its pin description (Pin 1 function) and Selector Guide. When asserted, RESET goes high; when deasserted, it returns low. This differs from MAX6864 variants (active-low) and MAX6865's own alternate versions like MAX6865UK16D1L+T (same pinout, different watchdog timeout).

What is the watchdog timeout period for the MAX6865UK16D1S+T?

The MAX6865UK16D1S+T features a 3.3s typical watchdog timeout period, indicated by the "S" suffix in its part number. Table 3 (Watchdog Timeout) confirms "S" = 1.5s (min) / 3.3s (typ) / 7.75s (max). The timer resets on any rising or falling edge at WDI (Pin 4), and expires only if WDI remains static beyond this window.

Can the MAX6865UK16D1S+T operate reliably at VCC = 1.2V?

Yes - the MAX6865UK16D1S+T is fully specified to operate from VCC = 1.2V to 5.5V. Its reset output remains valid down to VCC = 1.1V, and supply current is characterized at 1.2V (190nA typ). Electrical Characteristics confirm functional operation including MR input recognition, WDI edge detection, and RESET assertion/deassertion across this full range.

Is the MAX6865UK16D1S+T pin-compatible with other devices in the MAX68xx family?

The MAX6865UK16D1S+T uses the standard 5-pin SOT23 package and shares identical pinout with MAX6864/MAX6866/MAX6867–MAX6869 variants (Pin 1=RESET, Pin 2=GND, Pin 3=MR, Pin 4=WDI, Pin 5=VCC). However, it is not pin-compatible with MAX6861–MAX6863 (which use CT instead of WDI) or MAX6854–MAX6856 (which lack WDI entirely).