Analog Devices Inc./Maxim Integrated MAX6865UK23D3S+T

Overview

The MAX6865UK23D3S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 2.313V reset threshold (suffix "23"), 150ms minimum reset timeout (suffix "D3"), and watchdog timer with 3.3s typical timeout (suffix "S"). It monitors VCC, responds to manual reset (MR), and triggers reset on watchdog expiration - designed for battery-critical applications like glucose monitors and portable medical devices.

For engineers reviewing the MAX6865UK23D3S+T datasheet, MAX6865UK23D3S+T pinout, MAX6865UK23D3S+T application, or MAX6865UK23D3S+T equivalent, this page delivers verified functional identity, exact reset threshold and timeout values, watchdog timing behavior, SOT23-5 terminal mapping, and validated alternative parts for low-power µP supervision where VCC ≥ 1.2V and guaranteed reset validity down to 1.1V are required.

Technical Context

The MAX6865UK23D3S+T integrates three core functions: precision voltage monitoring with ±2.5% threshold accuracy over temperature, a manual reset input (MR) with 250ns delay and internal 10kΩ pull-up, and a watchdog timer that clears on any WDI edge and expires after 3.3s (typ) if inactive - all operating from 1.2V to 5.5V supply.

Its reset output is active-high push-pull (per MAX6865 variant), asserted when VCC < 2.313V, MR is low, or watchdog expires; deassertion occurs only after VCC exceeds threshold *and* the 150ms timeout elapses. Guaranteed reset validity to VCC = 1.1V ensures reliable operation during deep brownout conditions.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, -40°C to +85°C industrial temperature range.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6865UK23D3S+T, MAX6864UK23D3S+T offers identical supervision timing but inverted reset polarity, while TPS3836K33DBVR trades watchdog functionality and nanopower operation for lower unit cost and simpler qualification - making MAX6865UK23D3S+T optimal for safety-critical, long-life, watchdog-dependent medical wearables.

Availability

MAX6865UK23D3S+T is available at Aetrix Electronics and suitable for glucose monitors, patient monitors, wearable health trackers, and industrial handheld scanners requiring stable component supply across extended product lifecycles.

Supply support for MAX6865UK23D3S+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 communications applications.

The MAX68xx family delivers nanopower µP supervision with integrated watchdog and manual reset - engineered specifically for battery-powered medical instrumentation and portable electronics where reliability, ultra-low ICC, and guaranteed brownout response are critical.

FAQ

What is the exact reset threshold voltage of the MAX6865UK23D3S+T?

The MAX6865UK23D3S+T has a factory-trimmed reset threshold of 2.313V, with ±2.5% tolerance over the -40°C to +85°C temperature range. This value is confirmed by the "23" suffix in the part number per Maxim's Threshold Suffix Guide (Table 2), and is guaranteed valid down to VCC = 1.1V. The MAX6865UK23D3S+T uses this precise threshold to supervise 2.3V rails in medical sensors without external calibration.

Does the MAX6865UK23D3S+T include a watchdog timer, and what is its timeout?

Yes, the MAX6865UK23D3S+T includes a watchdog timer with a typical timeout of 3.3 seconds, indicated by the "S" suffix in the part number (Table 3). The timer clears on any rising or falling edge at the WDI pin and expires only if WDI remains static longer than 3.3s (typ). This behavior is fully documented in the MAX6865UK23D3S+T electrical characteristics and functional diagram.

What type of reset output does the MAX6865UK23D3S+T provide?

The MAX6865UK23D3S+T provides an active-high push-pull reset output, as defined by the MAX6865 variant in the Selector Guide. Pin 1 drives high during reset assertion and low when deasserted, referenced to VCC, eliminating the need for an external pull-up resistor. This matches MCUs with active-high reset inputs and is distinct from open-drain or active-low variants in the same family.

What is the minimum reset timeout period for the MAX6865UK23D3S+T?

The MAX6865UK23D3S+T has a minimum reset timeout period of 150ms, specified by the "D3" suffix per Table 4. This timeout begins after VCC rises above the 2.313V threshold and MR is deasserted, ensuring sufficient hold time for microprocessor power-up sequencing. The actual timeout ranges from 150ms (min) to 300ms (max) across temperature and voltage.

Is the MAX6865UK23D3S+T compatible with 1.8V supply systems?

Yes, the MAX6865UK23D3S+T operates across 1.2V to 5.5V, including 1.8V systems. Its 170nA typical supply current is measured at VCC = 1.8V, and it guarantees valid reset output down to VCC = 1.1V - making it suitable for modern ultra-low-voltage MCUs and sensors. The MAX6865UK23D3S+T maintains full specification compliance at 1.8V without derating.