Analog Devices Inc./Maxim Integrated MAX6865UK17D2L+T

Overview

The MAX6865UK17D2L+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, combining voltage monitoring (1.665V factory-trimmed reset threshold), manual reset input (MR), and watchdog timer (209s typical timeout) with ultra-low 170nA typical supply current. It asserts an active-low push-pull RESET output during VCC brownout, MR assertion, or watchdog timeout, maintaining reset for 40ms minimum after recovery - ideal for battery-powered glucose monitors and portable medical devices.

For engineers reviewing the MAX6865UK17D2L+T datasheet, MAX6865UK17D2L+T pinout, MAX6865UK17D2L+T application, or MAX6865UK17D2L+T equivalent, key selection criteria include its guaranteed reset validity down to VCC = +1.1V, immunity to short VCC transients (<40µs at 100mV overdrive), pin-selectable reset timeout options, and compatibility with low-voltage µP systems requiring long battery life and robust fault recovery.

Technical Context

The MAX6865UK17D2L+T implements a dual-monitoring architecture: a precision bandgap-based voltage detector with ±2.5% threshold accuracy across –40°C to +85°C, and a digital watchdog timer that clears on any WDI edge (rising or falling) and expires if WDI remains static beyond 209s (typ). Its internal 10kΩ MR pullup and glitch rejection (200ns) enable direct switch interfacing without external components.

Reset assertion is latched and held for a fixed 40ms minimum timeout (D2 option) after VCC rises above threshold or MR deasserts; the watchdog timeout (L suffix) is factory-set and temperature-stable (±15% over full range). The device operates from 1.2V to 5.5V and guarantees valid RESET output down to VCC = 1.1V, supporting deep brownout detection in ultra-low-power systems.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount, footprint compatible with industry-standard 5-pin SOT23 layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6865UK17D2L+T, the MAX6864UK16D2L+T offers a slightly lower reset threshold for tighter 1.65V rail monitoring, while the TPS3836K33DBVR provides pin-compatible supervision without watchdog - making MAX6865UK17D2L+T uniquely suited for low-power medical devices requiring both precise brownout detection and firmware hang protection.

Availability

MAX6865UK17D2L+T is available at Aetrix Electronics and suitable for glucose monitors, patient vital sign equipment, and industrial handheld scanners requiring stable component supply, long-term lifecycle support, and lead-free compliance.

Supply support for MAX6865UK17D2L+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 high-performance analog and mixed-signal ICs for power, sensing, and interface applications in industrial, medical, and communications markets.

The MAX6854–MAX6869 family was engineered specifically for ultra-low-power microprocessor supervision in battery-critical applications, integrating voltage monitoring, manual reset, and watchdog functions into minimal-area SOT23 packages.

FAQ

What is the exact reset threshold voltage of the MAX6865UK17D2L+T?

The MAX6865UK17D2L+T has a factory-trimmed reset threshold voltage of 1.665V, with ±2.5% tolerance over –40°C to +85°C. This value is defined by the '17' suffix in the part number and is verified per Table 2 (Threshold Suffix Guide) in the official datasheet. The threshold remains stable across temperature, with normalized variation <±0.5% from –40°C to +85°C.

Does the MAX6865UK17D2L+T require external components for basic operation?

No, the MAX6865UK17D2L+T requires no external components for core functionality: it includes an internal 10kΩ pullup on MR, edge-sensitive WDI detection, and a fixed 40ms reset timeout. Only a 0.1µF ceramic bypass capacitor on VCC to GND is recommended for noise immunity - no resistors, capacitors, or timing networks are needed for reset generation or watchdog operation.

How does the watchdog timer in the MAX6865UK17D2L+T respond to firmware activity?

The MAX6865UK17D2L+T watchdog timer clears on any rising or falling edge at the WDI pin and expires only if WDI remains static for >209s (typ). It does not require toggling; a single edge suffices. During reset assertion, the timer halts and resumes counting only after RESET deasserts - ensuring reliable detection of stuck loops without false timeouts during boot or recovery.

Can the MAX6865UK17D2L+T operate reliably at VCC = 1.2V?

Yes, the MAX6865UK17D2L+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). The device guarantees correct voltage monitoring, MR response, and watchdog timing across this entire range, making it suitable for deeply scaled battery-powered systems.

Is the MAX6865UK17D2L+T pin-compatible with other devices in the MAX68xx family?

Yes, the MAX6865UK17D2L+T uses the standard 5-pin SOT23-5 package and shares identical pinout (VCC, WDI, MR, GND, RESET) with all MAX6864–MAX6866 variants. It is also pin-compatible with TPS3836/TPS3837/TPS3838 devices, enabling drop-in replacement in existing designs where watchdog functionality is added or upgraded.