Analog Devices Inc./Maxim Integrated MAX6865UK32D5L+T

Overview

The MAX6865UK32D5L+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 3.2V reset threshold (±2.5%), and 300ms minimum reset timeout. 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 MAX6865UK32D5L+T datasheet, MAX6865UK32D5L+T pinout, MAX6865UK32D5L+T application, or MAX6865UK32D5L+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), and lead-free SOT23-5 packaging compliant with RoHS requirements.

Technical Context

This device belongs to the MAX6864–MAX6869 family, distinguished by integrated watchdog timer functionality with two selectable timeout options (S = 3.3s typ, L = 209s typ). The MAX6865UK32D5L+T specifically implements an active-high push-pull RESET output, MR input with 10kΩ internal pullup, and operates across VCC = 1.2V to 5.5V with full specification over –40°C to +85°C.

Its watchdog logic clears on any WDI edge (rising or falling), reset assertion, or MR assertion - ensuring robust software execution monitoring. The reset timeout period (D5 = 300ms min) is factory-fixed and independent of CT pin usage, as CT is not present on MAX6865 variants.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, RoHS-compliant surface-mount package measuring 2.9mm × 1.6mm × 1.1mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6864UK32D5L+T and TPS3836K33DBVR, the MAX6865UK32D5L+T uniquely delivers active-high reset signaling *plus* 209s watchdog supervision at nanopower levels - enabling fail-safe operation in medical wearables where both deterministic reset polarity and long-interval firmware verification are mandatory.

Availability

MAX6865UK32D5L+T is available at Aetrix Electronics and suitable for glucose monitors, portable ECG devices, and wireless patient alarms requiring stable component supply with guaranteed long-term manufacturability and RoHS-compliant sourcing.

Supply support for MAX6865UK32D5L+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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, medical, and communications applications.

The MAX6864–MAX6869 product line was engineered specifically for ultra-low-power supervisory functions in battery-operated medical and portable electronics, emphasizing nanoscale current consumption, wide VCC operating range, and robust watchdog reliability.

FAQ

What is the exact reset threshold voltage of the MAX6865UK32D5L+T?

The MAX6865UK32D5L+T has a factory-trimmed reset threshold of 3.200V with ±2.5% tolerance over –40°C to +85°C, corresponding to the "32" suffix in the part number per Maxim's Threshold Suffix Guide (Table 2). This value is guaranteed by design and tested during production screening.

Does the MAX6865UK32D5L+T require an external pullup resistor on the RESET pin?

No. The MAX6865UK32D5L+T features a push-pull active-high RESET output, which actively drives high or low without external components. Unlike open-drain variants, it does not require a pullup resistor - simplifying layout and reducing BOM count in space-constrained designs.

How does the watchdog timer in the MAX6865UK32D5L+T respond to software errors?

The MAX6865UK32D5L+T watchdog timer expires if the WDI pin remains static (high or low) for longer than 209s (typical, L-suffix). It clears on any edge transition, MR assertion, or RESET assertion - ensuring recovery from infinite loops, stalled peripherals, or firmware crashes without relying on precise toggle timing.

Can the MAX6865UK32D5L+T operate reliably at VCC = 1.5V?

Yes. The MAX6865UK32D5L+T is fully specified from VCC = 1.2V to 5.5V and guarantees RESET assertion validity down to VCC = +1.1V. At 1.5V, it maintains accurate 3.2V threshold monitoring, 170nA supply current, and functional watchdog timing - critical for lithium primary battery applications.

What is the meaning of the "D5L" suffix in MAX6865UK32D5L+T?

In MAX6865UK32D5L+T, "D5" denotes the 300ms minimum reset timeout period (per Table 4), and "L" specifies the 209s typical watchdog timeout (per Table 3). The "+T" indicates lead-free, RoHS-compliant packaging. These suffixes are factory-configured and non-adjustable in-circuit.