Analog Devices Inc./Maxim Integrated MAX6865UK43D2S+T

Overview

The MAX6865UK43D2S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, combining voltage monitoring (4.300V reset threshold), manual reset input (MR), and watchdog timer (3.3s timeout) with ultra-low 170nA typical supply current. It asserts an active-low push-pull RESET output during VCC brownout, MR assertion, or watchdog timeout, and holds reset for 40ms minimum after recovery - ideal for battery-powered glucose monitors and portable medical devices.

For engineers reviewing the MAX6865UK43D2S+T datasheet, MAX6865UK43D2S+T pinout, MAX6865UK43D2S+T application, or MAX6865UK43D2S+T equivalent, key selection criteria include its 4.300V factory-trimmed threshold, 40ms reset timeout, 3.3s watchdog period, guaranteed reset validity down to VCC = +1.1V, and immunity to short VCC transients ≤40µs at 100mV overdrive.

Technical Context

This device integrates a precision voltage comparator with ±2.5% threshold accuracy, a monostable reset timeout generator with fixed 40ms (D2) delay, and a watchdog timer that clears on any WDI edge and expires after 3.3s (S suffix) if inactive. Its BiCMOS process enables operation from 1.2V to 5.5V while maintaining nanoscale quiescent current.

The MR input features internal 10kΩ pullup and 200ns glitch rejection; RESET output delivers 0.3V max VOL at 1.2mA sink (VCC ≥ 2.38V) and 0.8×VCC VOH at 500µA source. Watchdog timing is temperature-stable, with normalized tWD variation <±20% across –40°C to +85°C.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6864UK43D2S+T, the MAX6865UK43D2S+T offers identical supervision functionality but belongs to a variant family supporting active-high RESET outputs (though this part uses active-low). Versus TPS3836K33DBVR, it adds critical watchdog capability and precise 4.300V threshold - essential for systems requiring both brownout and firmware hang protection.

Availability

MAX6865UK43D2S+T is available at Aetrix Electronics and suitable for portable medical devices, battery-powered industrial scanners, and smart wearables requiring stable component supply with long-term lifecycle support and lead-free compliance.

Supply support for MAX6865UK43D2S+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 MAX6865UK43D2S+T belongs to the MAX68xx nanopower supervisory family, engineered specifically for ultra-low-power, safety-critical portable electronics where extended battery life and robust fault detection are mandatory.

FAQ

What is the exact reset threshold voltage of the MAX6865UK43D2S+T?

The MAX6865UK43D2S+T has a factory-trimmed reset threshold of 4.300V, with ±2.5% tolerance over temperature (–40°C to +85°C). This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "43" corresponds to 4.300V nominal. The device guarantees valid reset assertion down to VCC = +1.1V, making it suitable for deep brownout detection in battery-powered systems.

Does the MAX6865UK43D2S+T include a watchdog timer, and what is its timeout period?

Yes, the MAX6865UK43D2S+T includes a watchdog timer with a typical timeout period of 3.3 seconds, indicated by the "S" suffix in the part number. The timer clears on any rising or falling edge at the WDI pin and expires only if WDI remains static beyond this period. This behavior is documented in Table 3 (Watchdog Timeout) and applies across the full operating temperature range.

What is the reset timeout duration for the MAX6865UK43D2S+T, and how is it configured?

The MAX6865UK43D2S+T has a fixed reset timeout period of 40ms (minimum), designated by the "D2" suffix. This value is not user-configurable - it is factory-set and matches the D2 option in Table 4 (Reset Timeout Periods). Unlike MAX6861–MAX6863 variants, the MAX6865UK43D2S+T does not include a CT pin for dynamic timeout selection.

What output type does the MAX6865UK43D2S+T provide, and how is it connected?

The MAX6865UK43D2S+T provides an active-low push-pull RESET output on Pin 1. This means it actively drives LOW during reset and HIGH (to VCC) when deasserted - no external pullup resistor is required. The output can sink up to 1.2mA at VCC ≥ 2.38V and source sufficient current to drive standard CMOS reset inputs directly.

Is the MAX6865UK43D2S+T pin-compatible with other supervisory ICs, and which ones?

The MAX6865UK43D2S+T is pin-compatible with the entire MAX6864–MAX6869 family (e.g., MAX6864UK43D2S+T, MAX6866UK43D2S+T) in the 5-pin SOT23 package. It shares identical pinout: Pin 1=RESET, Pin 2=GND, Pin 3=MR, Pin 4=WDI, Pin 5=VCC. It is not pin-compatible with MAX6861–MAX6863 (which use Pin 1 for CT) or MAX6854–MAX6856 (which lack WDI).