Analog Devices Inc./Maxim Integrated MAX6865UK16D6S+T

Overview

The MAX6865UK16D6S+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 1.575V reset threshold, 1200ms minimum reset timeout (D6), and integrated watchdog timer with 3.3s typical timeout (S suffix). 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 MAX6865UK16D6S+T datasheet, MAX6865UK16D6S+T pinout, MAX6865UK16D6S+T application, or MAX6865UK16D6S+T equivalent, key selection criteria include its guaranteed reset validity down to VCC = +1.1V, immunity to short VCC transients (<40µs at 100mV overdrive), pin-selectable reset delay capability (not applicable to this variant), and compatibility with low-voltage µP systems requiring long watchdog timeout and extended battery life.

Technical Context

This device implements a precision voltage monitor with ±2.5% reset threshold tolerance over –40°C to +85°C, combined with a digital watchdog timer that clears on any WDI edge and expires if WDI remains static beyond 3.3s (typ). Its internal 10kΩ MR pullup and glitch rejection (200ns) enable robust manual reset handling without external components.

The active-high push-pull RESET output delivers VOH ≥ 0.8×VCC (ISOURCE = 500µA) and VOL ≤ 0.3V (ISINK = 1.2mA), ensuring reliable interface with 1.8V–5.5V µP reset inputs. Reset assertion persists for the full 1200ms timeout after VCC rises above 1.575V or MR deasserts, with tRD < 40µs during VCC fall.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6864UK16D6S+T and TPS3836K33DBVR, the MAX6865UK16D6S+T uniquely combines MR input, 1.575V threshold, 1200ms timeout, and 3.3s watchdog in one nanopower package - making it the sole fit for battery-critical medical devices requiring both manual and automatic reset assurance.

Availability

MAX6865UK16D6S+T is available at Aetrix Electronics and suitable for glucose monitors, patient loggers, industrial wireless sensors, and low-power IoT trackers requiring stable component supply across extended production lifecycles.

Supply support for MAX6865UK16D6S+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, sensing, and connectivity in demanding industrial, medical, and automotive applications.

The MAX6854–MAX6869 family was engineered specifically for ultra-low-power microprocessor supervision in battery-operated medical and portable electronics, emphasizing nanoscale current consumption, wide VCC range, and robust reset timing under transient conditions.

FAQ

What is the reset threshold voltage of the MAX6865UK16D6S+T?

The MAX6865UK16D6S+T has a factory-trimmed reset threshold of +1.575V, with ±2.5% tolerance over –40°C to +85°C. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "16" corresponds to 1.575V. The threshold remains stable across temperature, with normalized variation < ±0.5% from –40°C to +85°C per typical operating characteristics.

Does the MAX6865UK16D6S+T include a manual reset input?

Yes, the MAX6865UK16D6S+T includes an active-low manual reset (MR) input on Pin 3. As documented in the MAX6864/MAX6865/MAX6866 Pin Description section, MR is internally pulled up to VCC via 10kΩ and accepts CMOS-compatible logic levels. Driving MR low initiates a reset that persists for the full 1200ms timeout period after MR returns high.

What watchdog timeout period does the 'S' suffix indicate in MAX6865UK16D6S+T?

The 'S' suffix in MAX6865UK16D6S+T specifies a typical watchdog timeout period of 3.3 seconds, with min/max values of 1.5s and 7.75s respectively (per Table 3, Watchdog Timeout). This timeout is implemented digitally and clears on any rising or falling edge at the WDI pin (Pin 4), ensuring responsiveness to software activity without requiring precise pulse timing.

What is the function of Pin 1 on the MAX6865UK16D6S+T?

Pin 1 of the MAX6865UK16D6S+T is the RESET output, configured as an active-high push-pull driver. As stated in the MAX6864/MAX6865/MAX6866 Pin Description, RESET transitions high when VCC drops below 1.575V, MR is pulled low, or the watchdog timer expires - and remains high for the full 1200ms timeout after recovery conditions are met.

Is the MAX6865UK16D6S+T compatible with 1.8V microcontrollers?

Yes, the MAX6865UK16D6S+T is fully compatible with 1.8V µPs. Its VCC operating range is 1.2V to 5.5V, and its active-high RESET output guarantees VOH ≥ 0.8×VCC (at ISOURCE = 500µA) and VOL ≤ 0.3V (at ISINK = 1.2mA) - meeting standard 1.8V logic high/low thresholds. The 1.575V reset threshold also aligns precisely with 1.8V supply brownout detection.