Analog Devices Inc./Maxim Integrated MAX6865UK36D2L+T

Overview

The MAX6865UK36D2L+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, a factory-trimmed 3.6V reset threshold (±2.5%), and dual watchdog timeout options (3.3s or 209s typ). It integrates voltage monitoring, manual reset input (MR), and watchdog timer (WDI) to ensure reliable system startup and fault recovery in battery-powered medical and portable electronics.

For engineers reviewing the MAX6865UK36D2L+T datasheet, MAX6865UK36D2L+T pinout, MAX6865UK36D2L+T application, or MAX6865UK36D2L+T equivalent, this device supports critical low-power supervision with guaranteed reset validity down to VCC = +1.1V, immunity to short VCC transients (<40µs at 100mV overdrive), and push-pull active-high RESET output compatible with 1.2V–5.5V supply rails.

Technical Context

The MAX6865UK36D2L+T implements a precision bandgap-based voltage monitor with 2.5% threshold tolerance and 0.5% hysteresis, coupled with a digital watchdog timer that clears on any WDI edge (rising or falling) and expires if WDI remains static beyond the selected timeout (L = 209s typ). Its internal 10kΩ MR pullup enables direct switch interfacing without external components.

Reset assertion occurs on VCC drop below 3.6V, MR low pulse (>1µs), or WDI timeout; deassertion follows a fixed 40ms minimum timeout (D2 option) after VCC rises above threshold and MR/WDI conditions clear. The push-pull active-high RESET output sources up to 500µA at VCC ≥ 2.38V while maintaining VOH ≥ 0.8×VCC.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6865UK36D2L+T, MAX6864UK36D2L+T offers identical supervision accuracy and watchdog capability but requires active-low reset handling, while TPS3837K33DBVR trades watchdog functionality and nanopower operation for lower unit cost in simpler systems.

Availability

MAX6865UK36D2L+T is available at Aetrix Electronics and suitable for portable medical devices, battery-powered instrumentation, and low-power wireless sensors requiring stable component supply with long-term lifecycle support.

Supply support for MAX6865UK36D2L+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 connectivity in demanding industrial and medical applications.

The MAX6854–MAX6869 family delivers nanopower supervision for battery-critical systems, with emphasis on ultra-low ICC, wide VCC range, and integrated watchdog functionality to replace discrete reset + timer solutions.

FAQ

What is the exact reset threshold voltage of the MAX6865UK36D2L+T?

The MAX6865UK36D2L+T has a factory-trimmed reset threshold of 3.600V with ±2.5% tolerance (3.510V to 3.690V), as defined by the "36" suffix per Table 2 in the datasheet. This value is guaranteed over -40°C to +85°C and applies to VCC falling conditions.

Does the MAX6865UK36D2L+T require external components for basic operation?

No, the MAX6865UK36D2L+T operates autonomously with no external components: MR is internally pulled up to VCC via 10kΩ, RESET is push-pull active-high, and VCC requires only a standard 0.1µF bypass capacitor. No pullups, resistors, or timing capacitors are needed for default configuration.

How does the watchdog timer in the MAX6865UK36D2L+T respond to WDI signal edges?

The MAX6865UK36D2L+T watchdog timer clears on any rising or falling edge at WDI (minimum pulse width 150ns) and expires only if WDI remains static for >209s (L suffix). It does not count while RESET is asserted, ensuring no false timeouts during active reset sequences.

What is the minimum VCC level at which MAX6865UK36D2L+T guarantees valid RESET output?

The MAX6865UK36D2L+T guarantees RESET output validity down to VCC = +1.1V, meaning the active-high RESET signal remains electrically functional and meets VOH/VOL specifications even during severe brownout conditions.

Can the MAX6865UK36D2L+T be used with a 1.2V supply rail?

Yes, the MAX6865UK36D2L+T operates across VCC = 1.2V to 5.5V and maintains full functionality-including 3.6V threshold monitoring, 209s watchdog, and 40ms reset timeout-at 1.2V, with ICC = 210nA typ and RESET VOH ≥ 0.8×VCC.