Analog Devices Inc./Maxim Integrated MAX6865UK36D6L+T

Overview

The MAX6865UK36D6L+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, combining voltage monitoring (3.600V reset threshold), manual reset input (MR), and watchdog timer (209s typical timeout) with ultra-low 170nA typical supply current. It asserts an active-high push-pull RESET output during VCC brownout, MR assertion, or watchdog timeout, and guarantees valid reset operation down to VCC = +1.1V - ideal for battery-powered glucose monitors and portable medical devices.

For engineers reviewing the MAX6865UK36D6L+T datasheet, MAX6865UK36D6L+T pinout, MAX6865UK36D6L+T application, or MAX6865UK36D6L+T equivalent, this device delivers deterministic reset timing (600–1200ms timeout), immunity to short VCC transients (<40µs at 100mV overdrive), and robust logic-level compatibility across 1.2V–5.5V supply range - critical for low-power embedded system reliability validation.

Technical Context

This device implements a precision bandgap-based voltage monitor with ±2.5% reset threshold accuracy and 0.5% hysteresis, coupled with a digital watchdog timer that clears on any WDI edge (rising or falling) and expires if WDI remains static beyond 209s (typ). The internal 10kΩ MR pullup enables direct switch interfacing without external components.

Its push-pull active-high RESET output drives high to VCC (≥0.8×VCC at 500µA source) and sinks low to ≤0.3V (at 1.2mA sink), ensuring clean logic-level signaling to µP reset inputs. The CT pin is absent - reset timeout is fixed at D6 (600–1200ms), distinguishing it from pin-selectable variants like MAX6861/MAX6862.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6864UK36D6S+T and TPS3836K33DBVR, the MAX6865UK36D6L+T uniquely combines long-interval watchdog supervision (209s), active-high push-pull output, and 3.600V precision threshold - enabling fail-safe operation in battery-constrained medical devices where both brownout resilience and extended firmware hang detection are mandatory.

Availability

MAX6865UK36D6L+T is available at Aetrix Electronics and suitable for glucose monitors, patient monitors, MP3 players, and feature phones requiring stable component supply with guaranteed long-term availability and lead-free compliance.

Supply support for MAX6865UK36D6L+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 management, sensing, and interface applications in industrial, medical, and consumer markets.

The MAX6854–MAX6869 family delivers nanopower supervisory functions - specifically engineered for battery-operated medical and portable electronics where ultra-low ICC, guaranteed reset validity at low VCC, and integrated watchdog capability are essential.

FAQ

What is the exact reset threshold voltage of the MAX6865UK36D6L+T?

The MAX6865UK36D6L+T has a factory-trimmed reset threshold of 3.600V, 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 "36" corresponds to 3.600V nominal. The MAX6865UK36D6L+T guarantees valid reset assertion when VCC falls below this threshold and holds reset for the full D6 timeout period thereafter.

Does the MAX6865UK36D6L+T include a manual reset input?

Yes, the MAX6865UK36D6L+T includes an active-low manual reset input (MR) on Pin 3. It features an internal 10kΩ pullup to VCC, accepts CMOS logic levels, and asserts reset when pulled low - with reset remaining active for the full D6 timeout period after MR returns high. This is explicitly documented in the MAX6864/MAX6865/MAX6866 Pin Description section.

What is the watchdog timeout period for the MAX6865UK36D6L+T?

The MAX6865UK36D6L+T has a watchdog timeout period of 209s typical (L-suffix), with min/max values of 95s/487s over temperature. This is specified in Table 3 ("Watchdog Timeout") and confirmed in the Ordering Information section, where "L" denotes the long watchdog option. The timer clears on any WDI edge and expires only if WDI remains static beyond this interval.

What type of RESET output does the MAX6865UK36D6L+T provide?

The MAX6865UK36D6L+T provides an active-high push-pull RESET output on Pin 1. Unlike open-drain variants, it sources current to drive high (≥0.8×VCC at 500µA) and sinks to drive low (≤0.3V at 1.2mA), eliminating the need for an external pullup resistor. This configuration is confirmed in the MAX6864/MAX6865/MAX6866 Pin Description and Selector Guide.

Is the MAX6865UK36D6L+T compatible with 1.8V supply systems?

Yes, the MAX6865UK36D6L+T operates across 1.2V to 5.5V, including 1.8V systems. Its supply current remains ultra-low (170nA typ), RESET output meets VOH/VOL specs at 1.8V (VOH ≥ 0.8×VCC, VOL ≤ 0.3V), and reset threshold accuracy is maintained. Electrical Characteristics tables confirm performance at VCC = 1.8V, and the device guarantees reset validity down to VCC = +1.1V - making it suitable for modern low-voltage µPs.