Analog Devices Inc./Maxim Integrated MAX6865UK46D5L+T

Overview

The MAX6865UK46D5L+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 4.625V reset threshold (±2.5%), and a 300ms minimum reset timeout period. It integrates manual reset input (MR), watchdog timer with 209s typical timeout, and push-pull active-high RESET output - designed for reliable power-up/brownout monitoring in battery-critical systems like glucose monitors and portable medical devices.

For engineers reviewing the MAX6865UK46D5L+T datasheet, MAX6865UK46D5L+T pinout, MAX6865UK46D5L+T application, or MAX6865UK46D5L+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 pulse detection capability (≥150ns), and lead-free SOT23-5 packaging compliant with industrial temperature range (–40°C to +85°C).

Technical Context

This device implements a dual-monitoring architecture: a precision voltage detector with hysteresis (0.5% of VTH) triggers reset on VCC drop below 4.625V, while an independent watchdog timer monitors WDI activity - expiring if no edge occurs within 209s (typ). Reset assertion persists for ≥300ms after VCC recovery and MR deassertion, ensuring µP initialization completes.

The MR input features internal 10kΩ pullup, 1µs minimum pulse width support, and 200ns glitch rejection. The push-pull active-high RESET output delivers VOH ≥ 0.8×VCC (at ISOURCE = 500µA, VCC ≥ 2.38V) and VOL ≤ 0.3V (at ISINK = 1.2mA, VCC ≥ 2.38V), enabling direct interface with 1.8V–5.5V logic domains without external components.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6864UK46D5L+T, the MAX6865UK46D5L+T avoids signal inversion overhead in active-high reset architectures; versus TPS3838K33DBVR, it delivers 9.4× lower supply current and adds critical watchdog protection for firmware integrity - essential in regulated medical electronics.

Availability

MAX6865UK46D5L+T is available at Aetrix Electronics and suitable for glucose monitors, patient vital sign recorders, industrial handheld scanners, and smart wearable health trackers requiring stable component supply across extended production lifecycles.

Supply support for MAX6865UK46D5L+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 demanding industrial, medical, and communications applications, emphasizing low power, high reliability, and small form factor.

The MAX6865UK46D5L+T belongs to the MAX68xx nanopower supervisory family, engineered specifically for battery-constrained medical and portable electronics where sub-µA quiescent current and guaranteed reset behavior at ultra-low VCC are mandatory.

FAQ

What is the exact reset threshold voltage of the MAX6865UK46D5L+T?

The MAX6865UK46D5L+T has a factory-trimmed reset threshold voltage of +4.625V, with a tolerance of ±2.5% over the –40°C to +85°C temperature range. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "46" corresponds to 4.625V nominal. The device guarantees valid reset assertion down to VCC = +1.1V, making it suitable for brownout detection in Li-ion-powered systems.

Does the MAX6865UK46D5L+T include a watchdog timer, and what is its timeout?

Yes, the MAX6865UK46D5L+T includes a watchdog timer with a typical timeout of 209 seconds, denoted by the "L" suffix in the part number. This is verified in Table 3 (Watchdog Timeout) and the Ordering Information section. The timer resets on any rising or falling edge at the WDI pin and expires only if WDI remains static beyond the timeout period - providing robust supervision for long-duration firmware routines in medical devices.

What type of reset output does the MAX6865UK46D5L+T provide?

The MAX6865UK46D5L+T provides a push-pull active-high RESET output, as confirmed in the Pin Description section for MAX6865 and the Selector Guide. This means the RESET pin drives high during reset assertion and low otherwise, eliminating the need for an external pullup resistor and enabling direct interfacing with µPs that require active-high reset inputs.

What is the minimum reset timeout period for the MAX6865UK46D5L+T?

The MAX6865UK46D5L+T has a minimum reset timeout period of 300ms, indicated by the "D5" suffix in the part number. This is documented in Table 4 (Reset Timeout Periods), where D5 corresponds to 300ms (min), 450ms (typ), and 600ms (max). This duration ensures reliable µP initialization, including oscillator startup and register clearing, before release.

Is the MAX6865UK46D5L+T compatible with lead-free PCB assembly processes?

Yes, the MAX6865UK46D5L+T uses lead-free packaging, as indicated by the "+T" suffix per Maxim's ordering convention (replacing "-T" for leaded versions). It is qualified for standard Pb-free reflow profiles, including peak temperatures up to +260°C, and meets JEDEC J-STD-020 moisture sensitivity level 1 - enabling compatibility with automated SMT lines used in high-reliability medical electronics manufacturing.