Analog Devices Inc./Maxim Integrated MAX6865UK46D6S+T

Overview

The MAX6865UK46D6S+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 4.625V reset threshold (±2.5%), 1200ms minimum reset timeout, manual reset input (MR), and watchdog timer with 209s typical timeout. It asserts active-high push-pull RESET during VCC brownout, MR assertion, or watchdog expiration - used in battery-powered medical monitors and portable instrumentation.

For engineers reviewing the MAX6865UK46D6S+T datasheet, MAX6865UK46D6S+T pinout, MAX6865UK46D6S+T application, or MAX6865UK46D6S+T equivalent, key selection criteria include guaranteed RESET validity down to VCC = +1.1V, immunity to ≤40µs VCC transients at 100mV overdrive, pin-selectable watchdog enable/disable via WDI logic transitions, and compatibility with 1.2V–5.5V supply rails.

Technical Context

This device integrates three core functions: precision voltage monitoring with hysteresis (0.5% of VTH), a glitch-immune manual reset input with 250ns MR-to-RESET delay and 1µs minimum pulse width, and a watchdog timer that clears on any WDI edge and expires if WDI remains static beyond 209s (typ). The internal 10kΩ MR pullup eliminates external components.

The reset output is active-high push-pull, referenced to VCC, with VOH ≥ 0.8×VCC (ISOURCE = 500µA) and VOL ≤ 0.3V (ISINK = 1.2mA). Watchdog timeout exhibits ±25% variation over temperature (–40°C to +85°C), and reset timeout is stable within ±2% across temperature.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, 2.9mm × 1.6mm × 1.1mm, lead-free (RoHS-compliant), thermal pad not present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6864UK46D6S+T and TPS3838K33DBVR, the MAX6865UK46D6S+T uniquely delivers active-high push-pull RESET at 4.625V threshold with integrated 209s watchdog - enabling single-chip supervision of high-reliability, battery-critical systems without compromise on timing or interface compatibility.

Availability

MAX6865UK46D6S+T is available at Aetrix Electronics and suitable for glucose monitors, patient vital signs recorders, industrial handheld scanners, and low-power wireless sensor nodes requiring stable component supply across extended production lifecycles.

Supply support for MAX6865UK46D6S+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 MAX6865UK46D6S+T belongs to the MAX68xx nanopower supervisory family, engineered specifically for ultra-low-power, high-reliability reset and watchdog functionality in battery-constrained medical and portable electronics.

FAQ

What is the exact reset threshold voltage of the MAX6865UK46D6S+T?

The MAX6865UK46D6S+T has a factory-trimmed reset threshold of +4.625V, with guaranteed tolerance of ±2.5% over –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 typical. The device asserts RESET when VCC falls below this threshold and holds it for the D6 timeout period (600–1200ms min) after VCC recovers.

Does the MAX6865UK46D6S+T support active-high reset output?

Yes, the MAX6865UK46D6S+T provides an active-high push-pull RESET output (Pin 1), as confirmed in its pin description and Selector Guide. Unlike open-drain or active-low variants, this output drives high during reset assertion and low when deasserted - directly compatible with microprocessors requiring active-high reset signaling without external inverters or pullups.

What is the watchdog timeout behavior of the MAX6865UK46D6S+T?

The MAX6865UK46D6S+T features a watchdog timer with 209s typical timeout (L suffix), with min/max values of 95s and 487s over temperature. The timer clears on any rising or falling edge at WDI (Pin 4) and expires only if WDI remains static beyond the timeout. During reset assertion, the watchdog is disabled and resumes counting only after RESET deasserts.

Can the MAX6865UK46D6S+T operate reliably at low supply voltages?

Yes, the MAX6865UK46D6S+T guarantees functional reset assertion down to VCC = +1.1V, as specified in the Electrical Characteristics table. Its supply voltage range is 1.2V to 5.5V, and RESET remains valid across this entire range - making it suitable for deep-brownout detection in battery-powered systems approaching end-of-life.

Is the MAX6865UK46D6S+T pin-compatible with other MAX68xx devices?

The MAX6865UK46D6S+T uses the standard 5-pin SOT23-5 package and shares identical pinout with MAX6864/MAX6866/MAX6867–MAX6869 (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 CT instead of WDI) or MAX6854–MAX6856 (which lack WDI), per the Selector Guide and Pin Configurations section.