Analog Devices Inc./Maxim Integrated MAX6869UK16D1S+

Overview

The MAX6869UK16D1S+ from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 1.575V reset threshold, 10ms minimum reset timeout, manual reset input (MR), and watchdog timer with 3.3s typical timeout. It asserts an active-low open-drain RESET output during VCC brownout, MR assertion, or watchdog expiration - used in battery-powered medical monitors and portable instrumentation.

For engineers reviewing the MAX6869UK16D1S+ datasheet, MAX6869UK16D1S+ pinout, MAX6869UK16D1S+ application, or MAX6869UK16D1S+ equivalent, key selection criteria include guaranteed RESET validity down to VCC = +1.1V, immunity to short VCC transients (<40µs at 100mV overdrive), watchdog pulse detection as short as 150ns, and compatibility with 1.2V–5.5V supply rails.

Technical Context

The MAX6869UK16D1S+ integrates three core functions: precision voltage monitoring with ±2.5% threshold accuracy over temperature, a glitch-immune manual reset input with 250ns MR-to-RESET delay and internal 10kΩ pullup, and a watchdog timer that clears on any WDI edge and expires if WDI remains static beyond 3.3s (typ).

Its open-drain RESET output requires an external pullup and sinks up to 1.2mA at VCC ≥ 2.38V while maintaining VOL ≤ 0.3V; the device guarantees functional reset assertion even as VCC falls to +1.1V, enabling reliable operation in deep-brownout conditions common in coin-cell-powered systems.

Key Specifications

Pinout & Package

Package: 5-pin SOT23 (lead-free, +T suffix), 2.9mm × 1.6mm footprint, 1.1mm height - compatible with high-density portable PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6864UK16D3S+, the MAX6869UK16D1S+ delivers faster reset deassertion (10ms vs. 150ms) for rapid boot sequences, while differing from TPS3836K33DBVR by supporting sub-1.8V operation, integrated watchdog, and nanopower consumption - making it uniquely suitable for ultra-low-power medical and sensor-edge applications.

Availability

MAX6869UK16D1S+ is available at Aetrix Electronics and suitable for glucose monitors, portable ECG devices, wireless sensor nodes, and low-power IoT trackers requiring stable component supply across long-life battery-operated designs.

Supply support for MAX6869UK16D1S+ 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 management, sensing, and interface applications in demanding industrial, medical, and communications systems.

The MAX6854–MAX6869 family was engineered specifically for nanopower microprocessor supervision in battery-constrained devices, emphasizing ultra-low ICC, wide VCC range, and robust fault detection including VCC brownout, manual reset, and software hang monitoring.

FAQ

What is the exact reset threshold voltage of the MAX6869UK16D1S+?

The MAX6869UK16D1S+ has a factory-trimmed reset threshold of +1.575V, with ±2.5% tolerance over the full -40°C to +85°C temperature range. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "16" corresponds to 1.575V. The device guarantees valid RESET assertion down to VCC = +1.1V, making it suitable for ultra-low-voltage applications where other supervisors fail.

Does the MAX6869UK16D1S+ include a watchdog timer, and what is its timeout behavior?

Yes, the MAX6869UK16D1S+ includes a watchdog timer with a typical timeout of 3.3s (S-suffix), as specified in Table 3. The timer clears on any rising or falling edge at the WDI pin and expires only if WDI remains static (high or low) beyond that period. When it expires, it asserts the RESET output for the configured 10ms minimum timeout period - providing deterministic recovery from firmware lockups.

What type of RESET output does the MAX6869UK16D1S+ provide, and how is it configured?

The MAX6869UK16D1S+ provides an active-low open-drain RESET output (Pin 4), requiring an external pullup resistor to the target logic rail. This configuration allows level-shifting across different voltage domains - for example, monitoring a 1.575V rail while driving a 3.3V µP reset input. The datasheet confirms this in the MAX6867/MAX6868/MAX6869 Pin Description section and Selector Guide.

How does the MAX6869UK16D1S+ handle short VCC supply transients?

The MAX6869UK16D1S+ is immune to VCC transients under defined conditions: a 100mV overdrive glitch is tolerated if duration is ≤40µs, per the "Maximum VCC Transient Duration vs. Reset Threshold Overdrive" graph. This immunity prevents false resets in electrically noisy environments like motor-driven portable equipment or shared PCB power domains, without requiring additional filtering components.

Is the MAX6869UK16D1S+ pin-compatible with other devices in the MAX68xx family?

The MAX6869UK16D1S+ uses the standard 5-pin SOT23 package and shares identical pinout with MAX6867/MAX6868 (WDI on Pin 1, GND on Pin 2, MR on Pin 3, RESET on Pin 4, VCC on Pin 5). However, it is not pin-compatible with MAX6861–MAX6863 (which use CT on Pin 1) or MAX6854–MAX6856 (which place RESET on Pin 1). Always verify pin function alignment using the Pin Configurations diagram.