Analog Devices Inc./Maxim Integrated MAX6865UK24D1L+T

Overview

The MAX6865UK24D1L+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 2.4V reset threshold (±2.5%), 10ms minimum reset timeout, and integrated watchdog timer with 209s typical timeout. It monitors VCC, responds to manual reset (MR), and asserts active-high push-pull RESET during brownout, power-up, or watchdog expiration - used in battery-powered glucose monitors and portable medical devices.

For engineers reviewing the MAX6865UK24D1L+T datasheet, MAX6865UK24D1L+T pinout, MAX6865UK24D1L+T application, or MAX6865UK24D1L+T equivalent, key selection criteria include its guaranteed RESET validity down to VCC = +1.1V, immunity to short VCC transients (<40µs at 100mV overdrive), watchdog input (WDI) pulse detection as short as 150ns, and compatibility with CMOS-level MR/WDI inputs.

Technical Context

This device implements a precision bandgap-based voltage monitor with 0.5% hysteresis, a digital watchdog timer that clears on any WDI edge (rising or falling), and an internal 10kΩ MR pullup. The reset assertion logic combines three independent triggers: VCC falling below 2.4V, MR low, or WDI timeout - all forcing active-high RESET for ≥10ms after recovery.

The watchdog timeout is fixed at 209s (typ) with ±50% variation over temperature; the reset timeout is factory-set to D1 (10ms min); and the push-pull RESET output delivers VOH ≥ 0.8×VCC at ISOURCE = 500µA (VCC ≥ 2.38V) and VOL ≤ 0.3V at ISINK = 1.2mA (VCC ≥ 2.38V).

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 MAX6864UK24D1L+T and TPS3836K24DBVR, the MAX6865UK24D1L+T uniquely delivers active-high RESET, nanopower operation, and integrated watchdog - making it optimal for space-constrained, battery-critical medical and portable electronics where both low ICC and runtime fault detection are mandatory.

Availability

MAX6865UK24D1L+T is available at Aetrix Electronics and suitable for portable medical devices, battery-powered instrumentation, and low-power embedded controllers requiring stable component supply, long-term lifecycle support, and lead-free compliance.

Supply support for MAX6865UK24D1L+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 management, sensing, and interface applications across industrial, medical, and communications markets.

The MAX6854–MAX6869 family was engineered specifically for ultra-low-power microprocessor supervision in battery-constrained systems, integrating voltage monitoring, manual reset, and watchdog functions into minimal 5-pin SOT23 footprints.

FAQ

What is the reset threshold voltage of the MAX6865UK24D1L+T?

The MAX6865UK24D1L+T has a factory-trimmed reset threshold of 2.4V with ±2.5% tolerance over temperature (−40°C to +85°C). This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "24" corresponds to VTH = 2.4V nominal. The device guarantees valid RESET assertion down to VCC = +1.1V, ensuring reliable operation during brownout conditions.

Does the MAX6865UK24D1L+T include a watchdog timer, and what is its timeout?

Yes, the MAX6865UK24D1L+T includes a watchdog timer with a typical timeout of 209 seconds (L suffix), with a range of 95s to 487s over temperature. The timer clears on any rising or falling edge at the WDI pin and expires only if WDI remains static beyond the timeout period. This behavior is explicitly defined in Table 3 (Watchdog Timeout) and the MAX6864–MAX6869 pin description section.

What type of reset output does the MAX6865UK24D1L+T provide?

The MAX6865UK24D1L+T provides an active-high push-pull RESET output (pin 1), as confirmed by the MAX6865-specific pin description and Selector Guide. Unlike open-drain variants, this output drives high during reset assertion and low when deasserted, eliminating the need for an external pullup resistor and simplifying interface with µPs requiring active-high reset signals.

What is the supply current consumption of the MAX6865UK24D1L+T under typical operating conditions?

The MAX6865UK24D1L+T consumes 170nA typical supply current (ICC) at VCC = 1.8V and TA = +25°C, as specified in the Electrical Characteristics table. This ultra-low ICC enables multi-year operation on small coin-cell batteries - a core design objective validated across the MAX6864–MAX6869 series and confirmed in Figure toc02 (Supply Current vs. Temperature).

How is the reset timeout period configured on the MAX6865UK24D1L+T?

The reset timeout period on the MAX6865UK24D1L+T is factory-configured to 10ms minimum (D1 option), as indicated by the "D1" in the part number suffix. This fixed timeout is implemented internally and cannot be adjusted externally. The D1 option provides the shortest standard delay (10ms min / 15ms typ), ensuring rapid µP release after power stabilization while meeting JEDEC JESD78 reliability requirements.