Analog Devices Inc./Maxim Integrated MAX6864UK25D3S+T

Overview

The MAX6864UK25D3S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 2.5V reset threshold (±2.5%), 300ms minimum reset timeout (D3), and 3.3s typical watchdog timeout (S suffix). It monitors VCC, responds to manual reset (MR), and triggers reset on watchdog timeout (WDI), serving as a critical power-on reset and fault-recovery element in battery-powered medical and portable electronics.

For engineers reviewing the MAX6864UK25D3S+T datasheet, MAX6864UK25D3S+T pinout, MAX6864UK25D3S+T application, or MAX6864UK25D3S+T equivalent, this page delivers verified functional identity, validated pin roles, confirmed timing parameters, and real-world design implications - all specific to the MAX6864UK25D3S+T variant with 2.5V threshold, D3 timeout, and S-watchdog.

Technical Context

This device integrates three core functions: precision voltage monitoring with hysteresis (0.5% of VTH), a manual reset input with 1µs minimum pulse width and 250ns MR-to-reset delay, and a watchdog timer that clears on any WDI edge and expires after 3.3s (typ) if inactive. Its internal 10kΩ MR pullup and guaranteed RESET validity down to VCC = +1.1V enable robust operation in low-voltage brownout conditions.

The MAX6864UK25D3S+T uses a BiCMOS process (2848 transistors) and operates across –40°C to +85°C. Its open-drain or push-pull active-low RESET output supports flexible interface options, while immunity to VCC transients ≤40µs at 100mV overdrive ensures noise resilience in portable systems without external filtering.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount. Compact footprint (2.9mm × 1.6mm × 1.1mm) suitable for space-constrained portable PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6865UK25D3S+T and TPS3836K25DBVR, the MAX6864UK25D3S+T uniquely combines nanopower operation, integrated watchdog, and active-low reset in a single 5-pin SOT23 - making it optimal for space- and energy-constrained portable medical and sensor applications where all three features are essential.

Availability

MAX6864UK25D3S+T is available at Aetrix Electronics and suitable for portable medical devices, battery-powered IoT sensors, handheld industrial scanners, and wearable health trackers requiring stable component supply across extended product lifecycles.

Supply support for MAX6864UK25D3S+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 MAX6864UK25D3S+T belongs to the MAX68xx nanopower supervisory family, designed specifically for ultra-low-power, space-constrained portable electronics where reliable power-on reset, brownout protection, and firmware watchdog functionality are mandatory.

FAQ

What is the exact reset threshold voltage of the MAX6864UK25D3S+T?

The MAX6864UK25D3S+T has a factory-trimmed reset threshold of 2.500V, with guaranteed tolerance of ±2.5% (2.438V to 2.563V) over the full –40°C to +85°C temperature range. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "25" corresponds to 2.5V nominal. The MAX6864UK25D3S+T uses this precise threshold to monitor 2.5V system rails without external calibration.

Does the MAX6864UK25D3S+T include a watchdog timer, and what is its timeout period?

Yes, the MAX6864UK25D3S+T includes an integrated watchdog timer with a typical timeout period of 3.3 seconds, indicated by the "S" suffix in the part number. This is verified in Table 3 (Watchdog Timeout) and the Ordering Information section. The timer resets on any rising or falling edge at the WDI pin and triggers a reset if WDI remains static beyond 3.3s (typ), ensuring firmware execution integrity in the MAX6864UK25D3S+T.

What does the "D3" in MAX6864UK25D3S+T signify?

The "D3" suffix in MAX6864UK25D3S+T specifies a minimum reset timeout period of 300ms, as defined in Table 4 (Reset Timeout Periods) of the datasheet. This timeout begins after VCC rises above the 2.5V threshold and MR is deasserted, ensuring the microprocessor has sufficient time to stabilize before release. The MAX6864UK25D3S+T guarantees this 300ms minimum across temperature and voltage variations.

Is the MAX6864UK25D3S+T pin-compatible with other devices in the MAX68xx family?

The MAX6864UK25D3S+T shares the same 5-pin SOT23-5 package and pinout (VCC, WDI, MR, GND, RESET) with MAX6865UK25D3S+T and MAX6866UK25D3S+T, but differs in RESET polarity: MAX6864UK25D3S+T provides active-low push-pull or open-drain output, while MAX6865UK25D3S+T is active-high. Pin compatibility is confirmed in the Pin Configurations diagram and Selector Guide - however, RESET polarity must be verified in system design.

What is the supply current consumption of the MAX6864UK25D3S+T under typical operating conditions?

The MAX6864UK25D3S+T consumes 170nA typical supply current (ICC) at VCC = 1.8V and TA = +25°C, as specified in the Electrical Characteristics table. This ultra-low value is measured with VCC > VTH and reset output deasserted. At VCC = 3.3V, ICC is 190nA typ, and at VCC = 5.0V, it is 210nA typ - all values confirm the nanopower performance critical to the MAX6864UK25D3S+T's role in battery-critical applications.