Analog Devices Inc./Maxim Integrated MAX6869UK23D3S+T

Overview

MAX6869UK23D3S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 2.313V reset threshold, 150ms minimum reset timeout, manual reset input (MR), and watchdog timer with 3.3s typical timeout. It asserts active-low open-drain RESET during VCC brownout, MR assertion, or watchdog expiration - used in battery-powered medical monitors and portable electronics.

For engineers reviewing the MAX6869UK23D3S+T datasheet, MAX6869UK23D3S+T pinout, MAX6869UK23D3S+T application, or MAX6869UK23D3S+T equivalent, key selection criteria include guaranteed RESET validity down to VCC = +1.1V, immunity to short VCC transients (<40µs at 100mV overdrive), pin-selectable watchdog enable/disable via WDI, and compatibility with 1.2V–5.5V supply rails.

Technical Context

The MAX6869UK23D3S+T integrates voltage monitoring, manual reset control, and watchdog timer functionality in a single BiCMOS IC. Its reset logic asserts output when VCC falls below 2.313V (±2.5%), MR is pulled low, or WDI remains static beyond 3.3s (typ); reset remains asserted for ≥150ms after recovery.

It uses internal 10kΩ MR pullup and supports noise-immune operation with 200ns MR glitch rejection and 250ns MR-to-reset delay. The watchdog clears on any WDI edge (rising/falling) and is disabled only when WDI is held continuously high or low beyond timeout - no software configuration required.

Key Specifications

Pinout & Package

MAX6869UK23D3S+T is housed in a lead-free 5-pin SOT23-5 package (2.9mm × 1.6mm × 1.1mm), optimized for space-constrained portable PCBs. Pin 1 is WDI, Pin 2 is GND, Pin 3 is MR, Pin 4 is RESET (open-drain active-low), and Pin 5 is VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6864UK23D3S+T and TPS3838K23DBVR, MAX6869UK23D3S+T uniquely combines ultra-low ICC, open-drain flexibility, and integrated watchdog - critical for long-life, self-healing portable medical systems.

Availability

MAX6869UK23D3S+T is available at Aetrix Electronics and suitable for glucose monitors, patient loggers, portable pagers, and industrial handheld scanners requiring stable component supply across extended production lifecycles.

Supply support for MAX6869UK23D3S+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 communications markets.

The MAX6854–MAX6869 family delivers nanopower supervision for battery-critical systems - engineered specifically for multi-year operation in portable medical and consumer electronics where reliability and energy efficiency are non-negotiable.

FAQ

What is the exact reset threshold voltage of MAX6869UK23D3S+T?

The MAX6869UK23D3S+T has a factory-trimmed reset threshold of 2.313V with ±2.5% tolerance over -40°C to +85°C, as defined by the "23" suffix per Maxim's Threshold Suffix Guide (Table 2). This value is laser-trimmed during production and does not require external calibration.

Does MAX6869UK23D3S+T support both manual reset and watchdog functions simultaneously?

Yes, MAX6869UK23D3S+T fully supports concurrent manual reset and watchdog operation. Pulling MR low or letting WDI remain static beyond 3.3s (typ) independently triggers RESET assertion, and the reset timeout period (≥150ms) applies identically in both cases.

What is the function of Pin 1 (WDI) on MAX6869UK23D3S+T?

Pin 1 of MAX6869UK23D3S+T is the Watchdog Input (WDI). It must be toggled with rising or falling edges at intervals <3.3s (typ) to prevent watchdog timeout. Static high or low states exceeding this period cause automatic RESET assertion for ≥150ms.

Can MAX6869UK23D3S+T operate with a 1.2V supply?

Yes, MAX6869UK23D3S+T operates across 1.2V to 5.5V. At 1.2V, it maintains full supervision functionality including RESET assertion, MR detection, and watchdog timing - though RESET sink current is reduced, and guaranteed validity extends only to VCC = +1.1V.

Is an external pullup resistor required for the RESET output of MAX6869UK23D3S+T?

Yes, MAX6869UK23D3S+T features an open-drain active-low RESET output (Pin 4), which requires an external pullup resistor to the target µP's logic supply (e.g., 1.8V, 3.3V, or 5V). Typical values range from 10kΩ to 100kΩ depending on rise time and bus capacitance requirements.