Analog Devices Inc./Maxim Integrated MAX6865UK25D1S+T

Overview

The MAX6865UK25D1S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, combining voltage monitoring (2.500V ±2.5% reset threshold), manual reset input (MR), and watchdog timer (209s typical timeout) with ultra-low 170nA supply current. It asserts an active-high push-pull RESET signal during VCC brownout, MR assertion, or watchdog timeout, maintaining reset for 10ms minimum after recovery - ideal for battery-powered glucose monitors and portable medical devices.

For engineers reviewing the MAX6865UK25D1S+T datasheet, MAX6865UK25D1S+T pinout, MAX6865UK25D1S+T application, or MAX6865UK25D1S+T equivalent, key selection criteria include its guaranteed reset validity down to VCC = +1.1V, immunity to short VCC transients (<40µs at 100mV overdrive), pin-selectable reset timeout options, and compatibility with low-voltage µP systems requiring long battery life and robust fault detection.

Technical Context

The MAX6865UK25D1S+T implements a dual-fault-detection architecture: a precision bandgap-based voltage monitor triggers reset when VCC falls below 2.500V (±2.5%), and a digital watchdog timer expires if WDI remains static beyond 209s (typ). Its internal 10kΩ MR pullup and glitch rejection (200ns) enable direct switch interfacing without external components.

Reset assertion is latched and held for a fixed 10ms minimum timeout after VCC recovery or MR deassertion; the active-high push-pull RESET output drives directly into µP reset inputs without external pullups, and operates reliably across -40°C to +85°C with guaranteed functionality down to VCC = 1.1V.

Key Specifications

Pinout & Package

MAX6865UK25D1S+T is housed in a RoHS-compliant, lead-free 5-pin SOT23-5 package (2.9mm × 1.6mm × 1.1mm), optimized for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6865UK25D1S+T, MAX6864UK25D1S+T offers identical supervision but inverted reset polarity, while TPS3836K25DBVR trades watchdog capability and nanopower operation for lower unit cost and simpler integration where firmware-level fault detection suffices.

Availability

MAX6865UK25D1S+T is available at Aetrix Electronics and suitable for portable medical devices, battery-powered wearables, and industrial handheld equipment requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX6865UK25D1S+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 MAX6865UK25D1S+T belongs to Maxim's nanopower µP supervisory family, designed specifically for ultra-low-power, safety-critical portable electronics where extended battery life and deterministic fault recovery are mandatory.

FAQ

What is the exact reset threshold voltage of the MAX6865UK25D1S+T?

The MAX6865UK25D1S+T has a factory-trimmed reset threshold of 2.500V with ±2.5% tolerance over -40°C to +85°C. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "25" corresponds to 2.500V nominal. The device guarantees valid reset assertion down to VCC = +1.1V, making it suitable for deep brownout scenarios in the MAX6865UK25D1S+T application space.

Does the MAX6865UK25D1S+T include a watchdog timer, and what is its timeout period?

Yes, the MAX6865UK25D1S+T includes a watchdog timer with a typical timeout period of 209 seconds, denoted by the "L" suffix in the part number. This is verified in Table 3 (Watchdog Timeout) and the Ordering Information section, which specifies "S" for 3.3s and "L" for 209s. The timer clears on any WDI edge transition and expires only if WDI remains static beyond this interval - a key reliability feature of the MAX6865UK25D1S+T.

What type of reset output does the MAX6865UK25D1S+T provide, and how is it configured?

The MAX6865UK25D1S+T provides an active-high push-pull reset output on Pin 1, as confirmed in the MAX6865-specific pin description (page 8) and Selector Guide. Unlike open-drain variants, this output drives high actively and requires no external pullup resistor. Its VOH is guaranteed ≥0.8×VCC at 500µA source current, ensuring robust interface with modern µP reset inputs - a defining characteristic of the MAX6865UK25D1S+T.

What is the supply current consumption of the MAX6865UK25D1S+T under typical operating conditions?

The MAX6865UK25D1S+T consumes 170nA typical supply current at +25°C with VCC = 2.5V and no load, as specified in the Electrical Characteristics table (ICC parameter). This ultra-low value is maintained across temperature and supply voltage (1.2V–5.5V), enabling multi-year operation on small batteries - a core design objective validated in the Typical Operating Characteristics plots (Figure toc01 and toc02) for the MAX6865UK25D1S+T.

How is the reset timeout period determined for the MAX6865UK25D1S+T, and what is its value?

The reset timeout period for the MAX6865UK25D1S+T is fixed at 10ms (minimum), indicated by the "D1" suffix in the part number per Table 4 (Reset Timeout Periods). This value is guaranteed across -40°C to +85°C and independent of VCC within specification. The timeout begins after VCC rises above the 2.500V threshold or MR deasserts, ensuring sufficient time for µP internal state initialization - a critical timing parameter for reliable MAX6865UK25D1S+T deployment.