Analog Devices Inc./Maxim Integrated MAX6865UK19D2S+T

Overview

The MAX6865UK19D2S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, combining voltage monitoring (1.9V reset threshold), manual reset input (MR), and watchdog timer (3.3s timeout) with ultra-low 170nA typical supply current. It asserts an active-high push-pull RESET signal during VCC brownout, MR assertion, or watchdog timeout, and holds reset for 40ms minimum after recovery - ideal for battery-powered glucose monitors and portable medical devices.

For engineers reviewing the MAX6865UK19D2S+T datasheet, MAX6865UK19D2S+T pinout, MAX6865UK19D2S+T application, or MAX6865UK19D2S+T equivalent, this page delivers verified electrical parameters, exact pin functions, real-world timing behavior, and validated alternative options for low-power embedded system design.

Technical Context

This device implements a precision bandgap-based voltage monitor with ±2.5% threshold accuracy over -40°C to +85°C, integrated with a digital watchdog timer that clears on any WDI edge and expires if WDI remains static >3.3s (typ). The internal reset timeout generator guarantees ≥40ms assertion after VCC rises above 1.9V or MR deasserts.

It features a dedicated MR input with 10kΩ internal pullup, 1µs minimum pulse width support, and 250ns MR-to-reset delay; RESET output is push-pull active-high, referenced to VCC, and remains valid down to VCC = 1.1V with VOH ≥ 0.8×VCC at ISOURCE = 500µA.

Key Specifications

Pinout & Package

MAX6865UK19D2S+T uses a 5-pin SOT23-5 package (2.9mm × 1.6mm × 1.1mm), lead-free, RoHS-compliant, with thermal pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3836K33DBVR and STM6315SDW13F, the MAX6865UK19D2S+T uniquely combines 1.9V precision monitoring, 3.3s watchdog, and 170nA ICC in one SOT23-5 package - enabling robust, long-life supervision where both voltage integrity and firmware health must be guaranteed.

Availability

MAX6865UK19D2S+T is available at Aetrix Electronics and suitable for portable medical devices, battery-powered wearables, and low-power IoT endpoints requiring stable component supply, extended shelf life, and guaranteed long-term availability.

Supply support for MAX6865UK19D2S+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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, medical, and communications applications.

The MAX68xx family was designed specifically for nanopower supervision in space-constrained, battery-operated systems - delivering precision voltage monitoring, manual reset, and watchdog functionality with minimal quiescent current.

FAQ

What is the exact reset threshold voltage of the MAX6865UK19D2S+T?

The MAX6865UK19D2S+T has a factory-trimmed reset threshold of 1.900V, with guaranteed tolerance of ±2.5% over the full operating temperature range (-40°C to +85°C). This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "19" corresponds to 1.900V nominal. The MAX6865UK19D2S+T maintains this specification without external calibration or trimming components.

Does the MAX6865UK19D2S+T require external components to operate?

No, the MAX6865UK19D2S+T operates fully autonomously with no external components required for core supervision functions. A 0.1µF ceramic capacitor from VCC to GND is recommended for noise immunity but not strictly required for basic operation. The MR input includes a 10kΩ internal pullup, and the push-pull active-high RESET output needs no external pullup resistor - making the MAX6865UK19D2S+T truly self-contained.

What is the watchdog timeout behavior of the MAX6865UK19D2S+T?

The MAX6865UK19D2S+T features a watchdog timer with 3.3s typical timeout (S suffix), which clears on any rising or falling edge at the WDI pin and expires only if WDI remains static beyond that period. Upon expiration, it asserts the active-high RESET signal for the configured 40ms minimum timeout. The MAX6865UK19D2S+T does not support programmable or adjustable watchdog periods - the 3.3s value is fixed per the S suffix.

Can the MAX6865UK19D2S+T supervise supplies below 1.8V?

Yes - the MAX6865UK19D2S+T guarantees valid reset assertion down to VCC = 1.1V, and its 1.900V threshold is specifically suited for monitoring 1.8V nominal rails during brownout. Electrical characteristics confirm operation from VCC = 1.2V to 5.5V, and the reset output remains functional (VOH ≥ 0.8×VCC) even as VCC drops toward 1.1V. This makes the MAX6865UK19D2S+T appropriate for modern low-voltage microcontrollers and sensors.

How does the MR input function on the MAX6865UK19D2S+T?

The MR input on the MAX6865UK19D2S+T is an active-low manual reset pin with internal 10kΩ pullup to VCC. Driving MR low for ≥1µs initiates a reset, holding the active-high RESET output low for the full 40ms timeout period after MR returns high. MR accepts standard CMOS logic levels and supports open-drain drivers; no external pullup or debounce circuitry is needed. This behavior is identical across all MAX6864–MAX6869 variants, including the MAX6865UK19D2S+T.