Analog Devices Inc./Maxim Integrated MAX6865UK46D6L+T

Overview

The MAX6865UK46D6L+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 4.625V reset threshold (±2.5%), and a 1200ms minimum reset timeout period. It integrates manual reset input (MR), watchdog timer with 209s typical timeout (L-suffix), and push-pull active-high RESET output - designed for reliable power-up/brownout monitoring in battery-critical systems like glucose monitors and portable medical devices.

For engineers reviewing the MAX6865UK46D6L+T datasheet, MAX6865UK46D6L+T pinout, MAX6865UK46D6L+T application, or MAX6865UK46D6L+T equivalent, key selection criteria include its guaranteed reset validity down to VCC = +1.1V, immunity to short VCC transients (<40µs at 100mV overdrive), watchdog pulse detection capability (150ns min), and lead-free SOT23-5 packaging compliant with RoHS requirements.

Technical Context

The MAX6865UK46D6L+T implements a dual-monitoring architecture: a precision voltage detector with hysteresis (0.5% of VTH) triggers reset when VCC falls below 4.625V, while an independent watchdog timer monitors WDI activity and expires if no edge occurs within 209s (typ). Reset assertion persists for ≥1200ms after VCC recovery and MR deassertion, ensuring µP initialization completes before release.

Its push-pull active-high RESET output delivers VOH ≥ 0.8×VCC (at ISOURCE = 500µA, VCC ≥ 2.38V) and VOL ≤ 0.3V (at ISINK = 1.2mA, VCC ≥ 2.38V), enabling direct interface with 1.8V–5.5V logic. The internal 10kΩ MR pullup and 20nA WDI input current minimize system power overhead.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, RoHS-compliant, 2.9mm × 1.6mm footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6865UK46D6L+T, MAX6864UK46D6L+T offers identical supervision parameters but inverted reset polarity, while TPS3838K33DBVR trades watchdog capability and ultra-low current for lower unit cost and simpler integration in static-voltage applications.

Availability

MAX6865UK46D6L+T is available at Aetrix Electronics and suitable for portable medical devices, industrial handheld scanners, smart wearables, and battery-powered IoT edge nodes requiring stable component supply across extended temperature ranges (-40°C to +85°C).

Supply support for MAX6865UK46D6L+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 communications markets.

The MAX6865UK46D6L+T belongs to the MAX68xx nanopower supervisory family, engineered specifically for ultra-low-power, high-reliability reset and watchdog functions in battery-constrained embedded systems.

FAQ

What is the exact reset threshold voltage of the MAX6865UK46D6L+T?

The MAX6865UK46D6L+T has a factory-trimmed reset threshold of +4.625V, with a tolerance of ±2.5% over the full operating temperature range (-40°C to +85°C). This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "46" corresponds to 4.625V nominal. The device guarantees valid reset assertion down to VCC = +1.1V, making it suitable for deep brownout detection in the MAX6865UK46D6L+T application space.

Does the MAX6865UK46D6L+T support both manual reset and watchdog functions simultaneously?

Yes, the MAX6865UK46D6L+T fully supports concurrent manual reset (MR) and watchdog (WDI) functionality. A low pulse on MR asserts reset independently of the watchdog state, and the watchdog timer expires if no edge occurs on WDI within 209s (typ). Both events trigger the same active-high RESET output for ≥1200ms. This dual-trigger capability is explicitly documented in the MAX6865UK46D6L+T Pin Description and Functional Diagram sections.

What is the watchdog timeout accuracy and temperature stability of the MAX6865UK46D6L+T?

The MAX6865UK46D6L+T watchdog timeout is specified as 95s (min), 209s (typ), and 487s (max) - corresponding to the "L" suffix per Table 3. Its normalized timeout vs. temperature curve (Figure MAX6854 toc04) shows variation within ±15% across -40°C to +85°C. This stability enables predictable firmware supervision in automotive cabin or industrial field deployments where the MAX6865UK46D6L+T operates without recalibration.

Can the MAX6865UK46D6L+T drive a 5V µP reset input directly?

Yes, the MAX6865UK46D6L+T's push-pull active-high RESET output can directly drive a 5V µP reset input. At VCC = 5.0V and ISOURCE = 500µA, VOH ≥ 0.8×VCC = 4.0V, exceeding standard TTL/CMOS high-level thresholds. The output is referenced to VCC, so no level-shifting is needed. This direct interface capability is verified in the Electrical Characteristics table under "RESET Output Voltage (VOH)" for the MAX6865UK46D6L+T.

Is the MAX6865UK46D6L+T pin-compatible with other devices in the MAX68xx family?

The MAX6865UK46D6L+T shares the same 5-pin SOT23-5 pinout as MAX6864/MAX6866/MAX6867–MAX6869 variants, with identical pin assignments: Pin 1 = RESET, Pin 2 = GND, Pin 3 = MR, Pin 4 = WDI, Pin 5 = VCC. However, it is not pin-compatible with MAX6861–MAX6863 (which use Pin 1 for CT) or MAX6854–MAX6856 (which lack WDI). This mapping is confirmed in the MAX6865/MAX6866 Pin Description and Pin Configurations diagrams.