Analog Devices Inc./Maxim Integrated MAX6865UK17D5S+T

Overview

The MAX6865UK17D5S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, combining voltage monitoring (1.665V reset threshold), manual reset input, and watchdog timer (3.3s typical timeout). It asserts an active-high push-pull RESET signal during VCC brownout, MR assertion, or watchdog expiration, with guaranteed reset validity down to VCC = +1.1V. It targets ultra-low-power portable medical and consumer devices requiring reliable power-on reset and firmware crash recovery.

For engineers reviewing the MAX6865UK17D5S+T datasheet, MAX6865UK17D5S+T pinout, MAX6865UK17D5S+T application, or MAX6865UK17D5S+T equivalent, key selection criteria include its 170nA typical supply current, factory-trimmed 1.665V reset threshold, 450ms minimum reset timeout (D5), 3.3s watchdog period (S suffix), and active-high push-pull output - all validated for -40°C to +85°C operation in battery-powered systems.

Technical Context

This device implements a precision bandgap-based voltage monitor with ±2.5% threshold accuracy over temperature, coupled with a digital watchdog timer that clears on any WDI edge and expires if WDI remains static beyond 3.3s (typ). The internal reset timeout generator provides fixed 450ms (D5) deassertion delay after VCC recovery or MR release.

Its active-high push-pull RESET output drives high with VOH ≥ 0.8×VCC at ISOURCE = 500µA (VCC ≥ 2.38V), while sinking capability is not applicable - eliminating need for external pullup. MR features 10kΩ internal pullup and 1µs minimum pulse width immunity.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount. Pin 1 is RESET (active-high push-pull), Pin 2 is GND, Pin 3 is MR (active-low manual reset), Pin 4 is WDI (watchdog input), Pin 5 is VCC (supply voltage input).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6865UK17D5S+T, MAX6864UK16D3S+T offers lower threshold and shorter timeout for tighter rail margins, while TPS3836K33DBVR provides cost-optimized basic supervision without watchdog - making MAX6865UK17D5S+T the only choice when 1.665V threshold, 450ms timeout, and 3.3s watchdog are jointly required.

Availability

MAX6865UK17D5S+T is available at Aetrix Electronics and suitable for glucose monitors, patient monitoring devices, MP3 players, and smart pagers requiring stable component supply across extended production lifecycles.

Supply support for MAX6865UK17D5S+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 supervisory functions - specifically engineered for battery-critical portable electronics where sub-µA quiescent current, accurate voltage thresholds, and integrated watchdog timers are mandatory.

FAQ

What is the exact reset threshold voltage of the MAX6865UK17D5S+T?

The MAX6865UK17D5S+T has a factory-trimmed reset threshold voltage of 1.665V (minimum 1.623V, maximum 1.707V) with ±2.5% tolerance over temperature. This value is encoded in the '17' suffix per Maxim's Threshold Suffix Guide and is verified across -40°C to +85°C. The MAX6865UK17D5S+T uses this precise threshold to reliably detect brownout on 1.8V system rails without external calibration.

Does the MAX6865UK17D5S+T provide watchdog timer functionality?

Yes, the MAX6865UK17D5S+T includes a watchdog timer with a typical timeout period of 3.3s, indicated by the 'S' suffix in the part number. The timer monitors the WDI pin and expires if no edge is detected within that interval, triggering a reset. The MAX6865UK17D5S+T watchdog clears on any rising or falling edge at WDI and is disabled during active RESET assertion - ensuring deterministic behavior during boot and error recovery.

What is the reset timeout period for the MAX6865UK17D5S+T?

The MAX6865UK17D5S+T has a minimum reset timeout period of 450ms, specified by the 'D5' portion of the part number. This timeout begins after VCC rises above the 1.665V threshold or after MR is released, and ensures the microprocessor remains held in reset long enough to stabilize power rails and internal clocks. The MAX6865UK17D5S+T guarantees this 450ms (min) / 600ms (typ) / 1200ms (max) window per electrical characteristics table.

What type of reset output does the MAX6865UK17D5S+T feature?

The MAX6865UK17D5S+T features an active-high push-pull reset output on Pin 1. Unlike open-drain variants, it actively drives high (VOH ≥ 0.8×VCC) and does not require an external pullup resistor. This simplifies PCB layout and ensures fast, rail-to-rail logic transitions compatible with modern µPs having active-high reset inputs. The MAX6865UK17D5S+T output remains asserted high during reset conditions including VCC brownout, MR assertion, and watchdog timeout.

Is the MAX6865UK17D5S+T compatible with standard SOT23-5 footprints?

Yes, the MAX6865UK17D5S+T uses a standard 5-pin SOT23-5 package with 0.95mm pitch and JEDEC MO-178AC outline. Its pinout (Pin 1: RESET, Pin 2: GND, Pin 3: MR, Pin 4: WDI, Pin 5: VCC) matches the MAX6864–MAX6866 series and is documented in Maxim's Pin Configurations diagram. The MAX6865UK17D5S+T is fully compatible with automated pick-and-place and reflow processes used for SOT23 components.