Analog Devices Inc./Maxim Integrated MAX6865UK30D1L+T

Overview

The MAX6865UK30D1L+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, combining voltage monitoring (3.000V 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 signal during VCC brownout, MR assertion, or watchdog timeout, and holds reset for 10ms minimum after recovery - ideal for battery-powered glucose monitors and portable medical devices.

For engineers reviewing the MAX6865UK30D1L+T datasheet, MAX6865UK30D1L+T pinout, MAX6865UK30D1L+T application, or MAX6865UK30D1L+T equivalent, key selection criteria include its guaranteed RESET validity down to VCC = +1.1V, immunity to short VCC transients (<40µs at 100mV overdrive), fixed 10ms reset timeout, and L-suffix 209s watchdog period - all critical for low-power embedded safety-critical systems.

Technical Context

This device implements a precision bandgap-based voltage monitor with ±2.5% threshold accuracy over -40°C to +85°C, coupled with a temperature-stable RC-based watchdog timer (L-suffix = 209s typ). Its internal 10kΩ MR pullup and glitch rejection (200ns) enable direct switch interfacing without external components.

The active-high push-pull RESET output delivers VOH ≥ 0.8×VCC at ISOURCE = 500µA (VCC ≥ 2.38V) and VOL ≤ 0.3V at ISINK = 1.2mA (VCC ≥ 2.38V), ensuring robust logic-level compatibility across 1.2V–5.5V supply rails while maintaining nanoscale quiescent current in both asserted and deasserted states.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5 (lead-free, +T suffix), footprint-compatible with industry-standard 5-lead SOT-23.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6865UK30D1L+T, MAX6864UK30D1L+T offers identical supervision specs but inverted RESET polarity, while TPS3836K33DBVR trades watchdog capability and nanopower operation for broader market availability - making MAX6865UK30D1L+T uniquely suited for compact, long-life, safety-aware 3.0V medical wearables.

Availability

MAX6865UK30D1L+T is available at Aetrix Electronics and suitable for glucose monitoring systems, portable patient vital sign monitors, industrial handheld scanners, smart wearable health trackers, and battery-powered IoT edge nodes requiring stable component supply with guaranteed long-term lifecycle support.

Supply support for MAX6865UK30D1L+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 small form factor.

The MAX6854–MAX6869 family delivers nanopower supervisory functions for battery-constrained systems, with the MAX6865UK30D1L+T specifically optimized for 3.0V medical wearables requiring guaranteed reset validity and long-interval watchdog supervision.

FAQ

What is the exact reset threshold voltage of the MAX6865UK30D1L+T?

The MAX6865UK30D1L+T has a factory-trimmed reset threshold of exactly 3.000V, with ±2.5% tolerance over the full -40°C to +85°C operating range. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "30" corresponds to 3.000V nominal. The device guarantees RESET assertion remains valid down to VCC = +1.1V, making it suitable for deep brownout detection in 3.0V systems.

Does the MAX6865UK30D1L+T include a watchdog timer, and what is its timeout period?

Yes, the MAX6865UK30D1L+T includes a watchdog timer with L-suffix configuration, providing a typical timeout period of 209 seconds (min 95s, max 487s). This is explicitly defined in Table 3 (Watchdog Timeout) and confirmed in the Ordering Information section, where "L" denotes the long watchdog interval. The timer resets on any rising or falling edge at the WDI pin and expires only if WDI remains static beyond the timeout window.

What type of RESET output does the MAX6865UK30D1L+T provide, and how is it electrically characterized?

The MAX6865UK30D1L+T provides an active-high push-pull RESET output. Per Electrical Characteristics, it delivers VOH ≥ 0.8 × VCC at ISOURCE = 500µA (for VCC ≥ 2.38V) and VOL ≤ 0.3V at ISINK = 1.2mA (for VCC ≥ 2.38V). This eliminates the need for an external pullup resistor and allows direct connection to µP reset inputs expecting active-high assertion, unlike open-drain or active-low variants in the same family.

What is the reset timeout period of the MAX6865UK30D1L+T, and is it adjustable?

The MAX6865UK30D1L+T has a fixed reset timeout period of 10ms minimum (D1 option), as indicated by the "D1" in its part number. This value is confirmed in Table 4 (Reset Timeout Periods) and cannot be adjusted - unlike the MAX6861–MAX6863 series, which feature a CT pin for selecting between 10ms and 150ms timeouts. The D1 timeout ensures rapid µP release after power stabilization while meeting minimum reset-hold requirements.

How does the MAX6865UK30D1L+T handle supply voltage transients, and what is its immunity specification?

The MAX6865UK30D1L+T is immune to short VCC transients up to 40µs duration when the overdrive is 100mV (i.e., VCC dips 100mV below the 3.000V threshold), as shown in Figure MAX684 toc05. This transient immunity prevents false resets in electrically noisy environments such as portable medical devices near RF sources or industrial scanners subject to ESD. The device achieves this through internal filtering and hysteresis (0.5% of VTH).