Analog Devices Inc./Maxim Integrated MAX6865UK37D1L+T

Overview

The MAX6865UK37D1L+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 3.7V reset threshold (±2.5%), 10ms minimum reset timeout, and integrated watchdog timer with 209s typical timeout. It monitors VCC, responds to manual reset (MR), and asserts active-high push-pull RESET during brownout, power-up, or watchdog expiry - used in battery-powered glucose monitors and portable medical devices.

For engineers reviewing the MAX6865UK37D1L+T datasheet, MAX6865UK37D1L+T pinout, MAX6865UK37D1L+T application, or MAX6865UK37D1L+T equivalent, this page delivers verified functional identity, exact pin roles, confirmed timing parameters, real-world use cases, and validated alternative options for low-power µP supervision in space-constrained, long-life systems.

Technical Context

The MAX6865UK37D1L+T implements a voltage-monitoring comparator with hysteresis (0.5% of VTH), a digital watchdog timer cleared by WDI edges, and an internal 10kΩ MR pullup. Its reset assertion logic combines VCC falling below 3.7V, MR low, or WDI inactivity exceeding 209s (typ), with guaranteed RESET validity down to VCC = 1.1V.

It uses BiCMOS process technology (2848 transistors) and operates across –40°C to +85°C. The device requires no external components, supports noise-immune operation via 200ns MR glitch rejection, and maintains immunity to VCC transients ≤40µs at 100mV overdrive.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount, 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 MAX6864UK37D1L+T and TPS3837K33DBVR, the MAX6865UK37D1L+T uniquely combines MR input, 3.7V precision threshold, minimal 10ms reset hold, and 209s watchdog - enabling robust, low-power supervision where both user intervention and long-duration software monitoring are essential.

Availability

MAX6865UK37D1L+T is available at Aetrix Electronics and suitable for glucose monitors, patient vital sign recorders, industrial handheld scanners, and smart wearable sensors requiring stable component supply across extended product lifecycles.

Supply support for MAX6865UK37D1L+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, mixed-signal, and power management ICs for demanding industrial, medical, and communications applications.

The MAX6865UK37D1L+T belongs to the MAX68xx nanopower supervisory family, engineered specifically for ultra-low-power, space-constrained battery-operated systems requiring reliable reset and watchdog functionality without external components.

FAQ

What is the exact reset threshold voltage of the MAX6865UK37D1L+T?

The MAX6865UK37D1L+T has a factory-trimmed reset threshold of 3.700V with ±2.5% tolerance (3.608V to 3.793V), as specified in Table 2 of the datasheet under suffix "37". This value is guaranteed over –40°C to +85°C and enables precise supervision of 3.3V systems with margin.

Does the MAX6865UK37D1L+T include a manual reset input?

Yes, the MAX6865UK37D1L+T includes an active-low manual reset input (MR) on Pin 3. It features an internal 10kΩ pullup to VCC, accepts CMOS logic levels, and requires a minimum 1µs pulse width. MR assertion forces RESET high for the full timeout period, even if VCC remains above threshold.

What is the watchdog timeout behavior of the MAX6865UK37D1L+T?

The MAX6865UK37D1L+T implements a watchdog timer with 209s typical timeout (L suffix), triggered when WDI (Pin 4) remains static longer than that period. The timer clears on any WDI edge (rising or falling), MR assertion, or RESET assertion - ensuring robust software execution monitoring without false triggers.

What package type and pin count does the MAX6865UK37D1L+T use?

The MAX6865UK37D1L+T is housed in a 5-pin SOT23-5 package (2.9mm × 1.6mm), lead-free, surface-mount. Pinout is: Pin 1 = RESET (active-high push-pull), Pin 2 = GND, Pin 3 = MR, Pin 4 = WDI, Pin 5 = VCC - matching the MAX6864–MAX6866 series configuration.

How does the MAX6865UK37D1L+T ensure reset validity during deep brownout?

The MAX6865UK37D1L+T guarantees valid RESET output down to VCC = 1.1V, meaning it continues asserting the correct logic level (high for RESET) even as supply voltage collapses - critical for predictable recovery in battery-powered medical devices where VCC may dip below 1.2V before shutdown.