Analog Devices Inc./Maxim Integrated MAX6865UK16D6L+T

Overview

The MAX6865UK16D6L+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, combining voltage monitoring, manual reset input (MR), and watchdog timer (WDI) functions. It asserts an active-low push-pull RESET when VCC drops below 1.575V (factory-trimmed threshold), MR is pulled low, or the watchdog times out after 209s (typ). Designed for ultra-low-power systems, it draws only 170nA (typ) at 2.5V and guarantees valid reset down to VCC = 1.1V.

For engineers reviewing the MAX6865UK16D6L+T datasheet, MAX6865UK16D6L+T pinout, MAX6865UK16D6L+T application, or MAX6865UK16D6L+T equivalent, this device serves as a critical power-on reset and software fault recovery element in battery-constrained portable electronics where supply current, brownout immunity, and watchdog timeout stability are design-critical parameters.

Technical Context

The MAX6865UK16D6L+T implements a dual-trigger reset architecture: one path monitors VCC against a precision 1.575V threshold with ±2.5% tolerance over –40°C to +85°C, while the second path detects WDI inactivity exceeding the factory-set 209s (typ) watchdog timeout. Its internal 10kΩ MR pullup and glitch rejection (200ns) enable robust manual reset without external components.

Reset assertion persists for a fixed 1200ms (D6 option) after VCC recovers above threshold and MR deasserts-or after watchdog expiration-ensuring sufficient µP initialization time. The push-pull active-low RESET output drives directly into CMOS inputs without pull-up resistors and remains functional down to VCC = 1.1V, supporting deep brownout detection.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount, 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 MAX6864UK16D6L+T, the MAX6865UK16D6L+T eliminates external pull-up needs and simplifies layout; versus TPS3836K33DBVR, it delivers 10× lower supply current and integrated watchdog-critical for energy-harvested or battery-limited designs.

Availability

MAX6865UK16D6L+T is available at Aetrix Electronics and suitable for portable medical devices, wearable health monitors, industrial handheld terminals, and low-power IoT sensors requiring stable component supply across extended production lifecycles.

Supply support for MAX6865UK16D6L+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 high-performance analog and mixed-signal ICs for power, sensing, and interface applications in demanding industrial, medical, and consumer systems.

The MAX6865UK16D6L+T belongs to the MAX68xx nanopower supervisory family, engineered specifically for battery-powered equipment where ultra-low ICC, precise voltage monitoring, and reliable software fault recovery are essential.

FAQ

What is the exact reset threshold voltage of the MAX6865UK16D6L+T?

The MAX6865UK16D6L+T has a factory-trimmed reset threshold voltage of +1.575V, with guaranteed tolerance of ±2.5% over the full operating temperature range (–40°C to +85°C). This value is confirmed by the "16" suffix in the part number per Maxim's Threshold Suffix Guide (Table 2), and applies to the VCC monitor input. The device asserts RESET when VCC falls below this threshold.

Does the MAX6865UK16D6L+T include a watchdog timer, and what is its timeout period?

Yes, the MAX6865UK16D6L+T includes a watchdog timer with a nominal timeout period of 209 seconds (typical), indicated by the "L" suffix in the part number per Table 3. The timer expires if no rising or falling edge is detected on the WDI pin within that interval, triggering a full reset timeout cycle. It is cleared automatically on any WDI edge, MR assertion, or RESET assertion.

What does the "D6" in MAX6865UK16D6L+T signify?

The "D6" suffix in MAX6865UK16D6L+T specifies the reset timeout period option: 600ms (min), 900ms (typ), and 1200ms (max), per Table 4. This defines the minimum duration RESET remains asserted after VCC rises above the 1.575V threshold and MR is deasserted-or after watchdog expiration-ensuring adequate µP initialization time.

Is the MAX6865UK16D6L+T pin-compatible with other devices in the MAX68xx family?

The MAX6865UK16D6L+T uses the standard 5-pin SOT23-5 package and shares identical pinout (RESET, GND, MR, WDI, VCC) with MAX6864/MAX6866/MAX6867–MAX6869 variants. However, it is not pin-compatible with MAX6861–MAX6863 (which use CT instead of WDI) or MAX6854–MAX6856 (which lack WDI). Always verify pin function alignment before substitution.

What is the supply current specification for the MAX6865UK16D6L+T under normal operating conditions?

The MAX6865UK16D6L+T draws 170nA typical supply current (ICC) at VCC = 2.5V and TA = +25°C, with a maximum of 400nA across temperature and voltage extremes. This ultra-low quiescent current is measured with RESET deasserted and no WDI activity, making it suitable for decade-long operation on primary lithium batteries.