Analog Devices Inc./Maxim Integrated MAX6865UK41D6L+T

Overview

The MAX6865UK41D6L+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, combining voltage monitoring (4.100V factory-trimmed 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, maintaining reset for 1200ms minimum after recovery - ideal for battery-powered glucose monitors and portable medical devices requiring long-term reliability and low quiescent power.

For engineers reviewing the MAX6865UK41D6L+T datasheet, MAX6865UK41D6L+T pinout, MAX6865UK41D6L+T application, or MAX6865UK41D6L+T equivalent, this page delivers verified technical context, exact pin functions, real-world timing behavior (tRP = 600–1200ms, tWD = 95–487s), and validated alternative options for low-power µP supervision in space- and energy-constrained systems.

Technical Context

The MAX6865UK41D6L+T implements a dual-trigger reset architecture: it monitors VCC against a precise +4.100V threshold (±2.5% over -40°C to +85°C), while independently tracking watchdog activity at the WDI input. Its internal watchdog timer clears on any rising or falling edge at WDI and expires if no transition occurs within the L-suffix timeout (95–487s, typ 209s), triggering a full reset sequence.

This device uses BiCMOS process technology (2848 transistors) to achieve guaranteed RESET validity down to VCC = +1.1V and immunity to VCC transients ≤40µs at 100mV overdrive. The active-high push-pull RESET output sources ≥500µA at VOH ≥0.8×VCC and sinks ≤0.3V at ISINK = 1.2mA, enabling direct interface with 1.71V–5.5V logic domains without external level-shifting.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5 (lead-free, +T suffix), footprint compatible with industry-standard 5-lead SOT23 layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6864UK41D6L+T and TPS3836K33DBVR, the MAX6865UK41D6L+T uniquely delivers active-high push-pull RESET, ultra-low 170nA ICC, and integrated 209s watchdog - making it the only option meeting simultaneous requirements for low-power medical wearables with deterministic reset polarity and runtime fault detection.

Availability

MAX6865UK41D6L+T is available at Aetrix Electronics and suitable for glucose monitors, patient vital sign recorders, industrial handheld scanners, and low-power IoT edge sensors requiring stable component supply across extended production lifecycles.

Supply support for MAX6865UK41D6L+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 demanding industrial, medical, and communications applications, emphasizing low power, high reliability, and integration.

The MAX6854–MAX6869 family was engineered specifically for nanopower microprocessor supervision in battery-critical systems - delivering factory-trimmed voltage thresholds, configurable timeouts, and watchdog timers in minimal 5-pin SOT23 packages.

FAQ

What is the exact reset threshold voltage of the MAX6865UK41D6L+T?

The MAX6865UK41D6L+T features a factory-trimmed reset threshold of +4.100V, with ±2.5% tolerance over the full -40°C to +85°C temperature range. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "41" corresponds to 3.998V (min), 4.100V (typ), and 4.203V (max). The device guarantees valid RESET assertion down to VCC = +1.1V, ensuring robust brownout response.

Does the MAX6865UK41D6L+T include a watchdog timer, and what is its timeout behavior?

Yes, the MAX6865UK41D6L+T includes a watchdog timer with L-suffix configuration, providing a typical timeout of 209s (min 95s, max 487s). The timer clears on any rising or falling edge at the WDI pin and expires only if WDI remains static beyond the timeout period - triggering a full reset sequence. This behavior is documented in Table 3 (Watchdog Timeout) and functional diagram Figure 1.

What type of RESET output does the MAX6865UK41D6L+T provide, and how is it interfaced?

The MAX6865UK41D6L+T provides an active-high push-pull RESET output (Pin 1), eliminating the need for an external pullup resistor. It sources ≥500µA at VOH ≥0.8×VCC and sinks ≤0.3V at ISINK = 1.2mA, enabling direct connection to µP reset inputs rated for 1.71V–5.5V logic. This is specified in the Electrical Characteristics table under VOH/VOL parameters and confirmed in the MAX6865 pin description on page 8.

What are the key timing parameters for reset assertion and deassertion in the MAX6865UK41D6L+T?

The MAX6865UK41D6L+T asserts RESET immediately when VCC falls below +4.100V, MR is pulled low, or the watchdog expires. After recovery, RESET remains asserted for a minimum of 600ms (D6 option, typ 900ms, max 1200ms) before deassertion. VCC-to-RESET delay (tRD) is 40µs maximum, and MR-to-RESET delay (tMRD) is 250ns - all confirmed in the Electrical Characteristics table on page 3.

Is the MAX6865UK41D6L+T compatible with standard SOT23-5 footprints and assembly processes?

Yes, the MAX6865UK41D6L+T uses a standard 5-pin SOT23-5 package (JEDEC MO-178AA), fully compatible with automated pick-and-place and reflow soldering. The "+T" suffix denotes lead-free packaging, qualified per JEDEC J-STD-020 moisture sensitivity level 1. Pin configuration matches Figure 15 (Pin Configurations) in the datasheet, with RESET (Pin 1), GND (Pin 2), MR (Pin 3), WDI (Pin 4), and VCC (Pin 5).