Analog Devices Inc./Maxim Integrated MAX6868UK23D1S+T

Overview

The MAX6868UK23D1S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, a factory-trimmed 2.23V reset threshold, 10ms minimum reset timeout, and integrated watchdog timer with 3.3s typical timeout. It monitors VCC, responds to manual reset (MR), and triggers reset on watchdog expiration - designed for battery-critical applications like glucose monitors and portable medical devices.

For engineers reviewing the MAX6868UK23D1S+T datasheet, MAX6868UK23D1S+T pinout, MAX6868UK23D1S+T application, or MAX6868UK23D1S+T equivalent, this page delivers verified functional identity, exact pin roles, confirmed timing parameters, watchdog behavior under voltage transients, and validated alternative options for low-power µP supervision.

Technical Context

The MAX6868UK23D1S+T implements a dual-trigger reset architecture: it asserts reset when VCC falls below 2.23V, when MR is pulled low, or when the watchdog input (WDI) remains static beyond 3.3s (typ). Its internal watchdog timer clears on any WDI edge, MR assertion, or active reset - enabling robust software execution monitoring in safety-critical embedded systems.

Reset output is push-pull active-low, guaranteed valid down to VCC = 1.1V, with 0.3V max VOL at 1.2mA sink and 0.8×VCC VOH at 500µA source. The device requires no external components, operates across –40°C to +85°C, and features 200ns MR glitch rejection and 250ns MR-to-reset delay.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount, 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 supervision applications.

Compared with MAX6868UK23D1S+T, MAX6864UK23D1S+T offers identical supervision specs but inverted reset polarity, requiring µP-level logic adaptation; TPS3836K33DBVR trades nanopower and watchdog capability for lower unit cost and simpler integration in static power-monitoring roles.

Availability

MAX6868UK23D1S+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 with long-term lifecycle support.

Supply support for MAX6868UK23D1S+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 industrial, medical, and communications applications.

The MAX6854–MAX6869 family delivers nanopower µP supervision with integrated watchdog timers, targeting battery-powered medical and portable electronics where ultra-low ICC and deterministic fault recovery are mandatory.

FAQ

What is the exact reset threshold voltage of the MAX6868UK23D1S+T?

The MAX6868UK23D1S+T has a factory-trimmed reset threshold voltage of 2.23V, 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 "23" corresponds to 2.23V nominal. The device guarantees valid reset assertion down to VCC = 1.1V, making it suitable for deep-brownout detection in low-voltage systems.

Does the MAX6868UK23D1S+T include a watchdog timer, and what is its timeout period?

Yes, the MAX6868UK23D1S+T includes a watchdog timer with a typical timeout period of 3.3s, indicated by the "S" suffix in the part number. The timer resets on any rising or falling edge at the WDI pin and triggers reset if WDI remains static beyond this period. Minimum and maximum timeout values are 1.5s and 7.75s respectively, ensuring robust fault detection across temperature and process variation.

What is the reset output configuration of the MAX6868UK23D1S+T?

The MAX6868UK23D1S+T features a push-pull active-high RESET output, as confirmed by the Selector Guide and MAX6868-specific pin description. Pin 4 outputs RESET (active-high), meaning it drives high during reset assertion and low during normal operation. This differs from MAX6864/MAX6867 variants and must be matched to the µP's reset input polarity.

What are the key timing parameters for manual reset operation on the MAX6868UK23D1S+T?

The MAX6868UK23D1S+T specifies a minimum MR pulse width of 1µs, MR-to-reset delay of 250ns, and 200ns glitch rejection. Its internal 10kΩ pullup ensures MR floats high when unused. These parameters enable reliable pushbutton reset implementation without external debounce, supporting both human-operated and automated test-system reset initiation.

Is the MAX6868UK23D1S+T compatible with 1.8V logic systems?

Yes, the MAX6868UK23D1S+T operates with VCC as low as 1.2V and supports full functionality down to 1.8V, including valid RESET output (VOH ≥0.8×VCC at 500µA source), WDI and MR input thresholds scaled to VCC (VIH = 0.7×VCC, VIL = 0.3×VCC), and 170nA supply current. It is fully specified for use in 1.8V microcontroller and sensor subsystems.