Analog Devices Inc./Maxim Integrated MAX6865UK19D6L+T

Overview

The MAX6865UK19D6L+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 1.9V reset threshold (±2.5%), 1200ms minimum reset timeout, manual reset input (MR), and watchdog timer with 209s typical timeout (L-suffix). It asserts active-high push-pull RESET during VCC brownout, MR assertion, or watchdog expiration - used in battery-powered glucose monitors and portable medical devices.

For engineers reviewing the MAX6865UK19D6L+T datasheet, MAX6865UK19D6L+T pinout, MAX6865UK19D6L+T application, or MAX6865UK19D6L+T equivalent, key selection criteria include guaranteed RESET validity down to VCC = +1.1V, immunity to short VCC transients (<40µs at 100mV overdrive), push-pull active-high output logic, and lead-free SOT23-5 packaging compliant with RoHS.

Technical Context

This device integrates three core functions: precision voltage monitoring with hysteresis (0.5% of VTH), a glitch-immune manual reset input with 1µs minimum pulse width and 200ns noise rejection, and a watchdog timer that clears on any WDI edge and expires if WDI remains static beyond 209s (typ). The internal 10kΩ MR pullup eliminates external components.

RESET timing is governed by two independent timeout mechanisms: a fixed 1200ms (D6) reset timeout after VCC recovery or MR release, and a watchdog timeout (L = 209s typ) triggered only when WDI stalls. The push-pull active-high RESET output drives directly to VCC with VOH ≥ 0.8×VCC at 500µA source current.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, RoHS-compliant, footprint compatible with industry-standard 5-pin SOT23 layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6864UK19D6L+T, the MAX6865UK19D6L+T provides active-high RESET compatibility without logic inversion, simplifying interface design; versus TPS3838K33DBVR, it delivers 10× lower ICC and integrated watchdog - critical for disposable medical wearables requiring multi-year shelf life and runtime reliability.

Availability

MAX6865UK19D6L+T is available at Aetrix Electronics and suitable for glucose monitors, portable ECG devices, smart inhalers, and wearable oximeters requiring stable component supply, long-term lifecycle support, and RoHS-compliant lead-free packaging.

Supply support for MAX6865UK19D6L+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 targets ultra-low-power battery-operated systems requiring reliable power-on reset, brownout protection, and software fault recovery - with emphasis on medical wearables and portable diagnostics.

FAQ

What is the exact reset threshold voltage of the MAX6865UK19D6L+T?

The MAX6865UK19D6L+T has a factory-trimmed reset threshold of 1.900V, with guaranteed tolerance of ±2.5% (1.853V to 1.948V) across -40°C to +85°C operating temperature. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "19" corresponds to 1.9V nominal. The MAX6865UK19D6L+T maintains this accuracy without external calibration.

Does the MAX6865UK19D6L+T support active-high or active-low reset output?

The MAX6865UK19D6L+T features an active-high push-pull RESET output, meaning RESET goes high (to VCC) when asserted and low when deasserted. This is confirmed in the MAX6865-specific pin description (page 8) and Selector Guide (page 16), which lists MAX6865 under "Push-Pull ACTIVE HIGH" with no open-drain or active-low variants for this part number.

What is the watchdog timeout period for the MAX6865UK19D6L+T?

The MAX6865UK19D6L+T uses the "L" watchdog suffix, providing a typical timeout of 209 seconds, with min/max range of 95s to 487s. This is specified in Table 3 (Watchdog Timeout) and confirmed in the Ordering Information section, where "L" follows the D6 reset timeout in the part number format MAX6865UK_ _D_ _L+T.

Can the MAX6865UK19D6L+T operate down to 1.2V supply voltage?

Yes, the MAX6865UK19D6L+T operates across VCC = 1.2V to 5.5V, and its RESET output remains valid down to VCC = +1.1V - ensuring reliable assertion during deep brownout conditions. This is explicitly guaranteed in the Absolute Maximum Ratings and Electrical Characteristics tables, and verified in Figure toc07 (VCC to RESET Delay vs. Temperature).

Is the MAX6865UK19D6L+T pin-compatible with other MAX68xx supervisory ICs?

The MAX6865UK19D6L+T uses the standard 5-pin SOT23-5 package and shares identical pinout (RESET, GND, MR, WDI, VCC) with MAX6864/MAX6866/MAX6867–MAX6869. However, it is not pin-compatible with MAX6854–MAX6863 due to absence of CT pin and presence of WDI - confirmed in Pin Configurations (page 15) and Selector Guide (page 16).