Analog Devices Inc./Maxim Integrated MAX6865UK20D5L+T

Overview

MAX6865UK20D5L+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 2.0V reset threshold (±2.5%), 300ms minimum reset timeout (D5), and integrated watchdog timer with 209s typical timeout (L suffix). It monitors VCC, responds to manual reset (MR), and triggers reset on watchdog expiration - ideal for battery-powered glucose monitors and portable medical devices.

For engineers reviewing the MAX6865UK20D5L+T datasheet, MAX6865UK20D5L+T pinout, MAX6865UK20D5L+T application, or MAX6865UK20D5L+T equivalent, this page delivers verified functional identity, exact reset timing values, watchdog behavior under temperature variation, MR input logic thresholds, and validated alternative options for low-power µP supervision.

Technical Context

The MAX6865UK20D5L+T implements a precision bandgap-based voltage monitor with 0.5% hysteresis, a digital watchdog timer cleared by WDI edges (min pulse width 150ns), and an internal 10kΩ MR pullup. Its reset assertion is guaranteed valid down to VCC = +1.1V, and it rejects VCC transients ≤40µs at 100mV overdrive.

This device belongs to the MAX6864–MAX6869 series with active-high push-pull RESET output, manual reset input (MR), and watchdog input (WDI). It uses BiCMOS process (2848 transistors) and operates across –40°C to +85°C with no external components required.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free (RoHS-compliant), 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 supervision applications.

Compared with MAX6865UK20D5L+T, MAX6864UK20D5S+T offers faster watchdog response but less sleep-friendly timing, while TPS3836K20DBVR trades off nanopower operation and watchdog capability for TI's production consistency and broader distribution - making MAX6865UK20D5L+T optimal for ultra-long-life, watchdog-critical medical wearables.

Availability

MAX6865UK20D5L+T is available at Aetrix Electronics and suitable for glucose monitors, patient monitoring devices, and smart pagers requiring stable component supply, extended battery life, and reliable watchdog supervision.

Supply support for MAX6865UK20D5L+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, mixed-signal, and power management ICs for demanding industrial, medical, and portable applications.

The MAX6864–MAX6869 family was engineered specifically for nanopower microprocessor supervision in battery-constrained medical and handheld devices, integrating voltage monitoring, manual reset, and configurable watchdog functionality in minimal 5-pin SOT23 form factor.

FAQ

What is the exact reset threshold voltage of MAX6865UK20D5L+T?

The MAX6865UK20D5L+T has a factory-trimmed reset threshold of 2.000V with ±2.5% tolerance over –40°C to +85°C. This value is confirmed in Table 2 (Threshold Suffix Guide) where suffix "20" corresponds to VTH = 2.000V, and electrical characteristics specify VTH = VTH ±2.5% at TA = –40°C to +85°C. The MAX6865UK20D5L+T guarantees reliable reset assertion when VCC falls below this precise threshold.

Does MAX6865UK20D5L+T support active-high or active-low reset output?

MAX6865UK20D5L+T provides an active-high push-pull RESET output, as confirmed by its pin description (Pin 1 = RESET, "Active-High Push-Pull Reset Output") and Selector Guide entry. When reset is asserted, RESET pin drives high; when deasserted, it drives low - eliminating need for external pullup resistors and simplifying interface to µP reset inputs expecting active-high signaling. This configuration is fixed for the MAX6865UK20D5L+T variant.

What is the watchdog timeout behavior of MAX6865UK20D5L+T?

The MAX6865UK20D5L+T features a watchdog timeout of 209s typical (L suffix), with min/max of 95s/487s over temperature. The internal timer clears on any WDI edge (rising or falling) and expires only if WDI remains static beyond this period, triggering a full reset cycle. This long timeout supports ultra-low-duty-cycle applications like periodic sensor wake-ups, and is validated in Table 3 ("Watchdog Timeout") and Electrical Characteristics section.

Can MAX6865UK20D5L+T operate down to 1.2V supply?

Yes - MAX6865UK20D5L+T is fully specified for operation from VCC = 1.2V to 5.5V per Absolute Maximum Ratings and Electrical Characteristics tables. Its reset function remains guaranteed down to VCC = +1.1V, and supply current is characterized at 1.2V (7µA max when reset asserted). This makes MAX6865UK20D5L+T suitable for systems using low-dropout regulators feeding 1.2V–1.8V logic rails.

Is MAX6865UK20D5L+T pin-compatible with other MAX68xx supervisory ICs?

MAX6865UK20D5L+T uses the standard 5-pin SOT23-5 package and shares identical pinout (Pin 1=RESET, Pin 2=GND, Pin 3=MR, Pin 4=WDI, Pin 5=VCC) with MAX6864/MAX6866 variants. However, it is not pin-compatible with MAX6861–MAX6863 (which use CT pin) or MAX6854–MAX6856 (which lack WDI). Direct substitution requires matching both function (watchdog + MR + active-high RESET) and pin assignment - confirmed in the Pin Configurations and Selector Guide.