Analog Devices Inc./Maxim Integrated MAX6373KA-T

Overview

MAX6373KA-T from Maxim Integrated is a pin-selectable watchdog timer IC designed to supervise microprocessor activity in safety-critical embedded systems. It features open-drain active-low WDO output with 100ms pulse width, operates from +2.5V to +5.5V, draws only 8–22µA supply current, and supports startup delay from 200µs to 60s and watchdog timeout from 30µs to 10s - used to reset or interrupt μP upon code execution failure.

For engineers reviewing the MAX6373KA-T datasheet, MAX6373KA-T pinout, MAX6373KA-T application, or MAX6373KA-T equivalent, key selection criteria include its open-drain WDO output timing, first-edge startup mode capability, pin-selectable timing configuration without power cycling, and AEC-Q100-qualified variants for automotive use.

Technical Context

The MAX6373KA-T implements a precision analog/digital hybrid watchdog circuit with three logic-controlled SET pins (SET0–SET2) that configure both startup delay and normal timeout periods independently. Its internal transition detector monitors rising/falling edges on WDI ≥100ns wide, ignoring inputs during WDO assertion and a 300µs internal setup window after power-up or setting changes.

Unlike fixed-timing supervisors, the MAX6373KA-T supports two extended startup modes (SET2=1, SET1=0, SET0=1 or SET2=1, SET1=1, SET0=0) where the timer initiates only upon the first valid WDI edge - enabling initialization windows beyond 60s. Its open-drain WDO requires an external pullup and sinks ≥1.2mA at 0.3V.

Key Specifications

Pinout & Package

MAX6373KA-T is housed in an 8-pin SOT23 package (package code K8SN-1/K8SN+1), measuring 2.9mm × 1.6mm × 1.1mm, with RoHS-compliant lead-free finish (+T suffix).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar watchdog timer applications.

Compared with MAX6371KA+T and TPS3808G33DBVR, the MAX6373KA-T uniquely supports both sub-millisecond startup (200µs) and first-edge initiation - critical for heterogeneous boot sequences - while retaining open-drain compatibility and automotive temperature range.

Availability

MAX6373KA-T is available at Aetrix Electronics and suitable for industrial PLC control, automotive body electronics, medical infusion pumps, and telecom remote radio units requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6373KA-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, automotive, and communications applications.

The MAX6369–MAX6374 family was engineered specifically for high-reliability microprocessor supervision - delivering pin-configurable timing, fail-safe outputs, and extended temperature operation without external components.

FAQ

What is the watchdog output type and drive capability of the MAX6373KA-T?

The MAX6373KA-T features an open-drain active-low watchdog output (WDO) that sinks ≥1.2mA at 0.3V when asserted. It requires an external pullup resistor (e.g., 10kΩ to VCC) and supports interface voltages up to +5.5V. This architecture enables wired-OR fault signaling and compatibility with diverse logic families - a core design feature confirmed in the Functional Diagram and Electrical Characteristics tables of the official datasheet for MAX6373KA-T.

How does the MAX6373KA-T support systems with variable or extended boot times?

The MAX6373KA-T supports variable boot times via two first-edge startup modes (SET2=1, SET1=0, SET0=1 or SET2=1, SET1=1, SET0=0), where the watchdog timer begins counting only after the first valid WDI transition - eliminating fixed timeout constraints. This capability, explicitly documented for MAX6373/MAX6374 in the Detailed Description and Selector Guide, ensures reliable supervision even for boot sequences exceeding 60 seconds without false resets - a key differentiator of MAX6373KA-T.

What are the minimum and maximum watchdog timeout periods supported by the MAX6373KA-T?

The MAX6373KA-T supports watchdog timeout periods ranging from 30µs to 10s, depending on the logic states of SET0, SET1, and SET2 pins. Specific values include 3ms (000), 3s (001), 1s (010), disabled (011), 30µs (100), 1s (101), 10s (110), and 10s (111), as tabulated in Table 1 of the datasheet. These values are guaranteed over -40°C to +125°C and form the basis for timing-critical supervision in MAX6373KA-T applications.

Can the MAX6373KA-T watchdog timer be disabled without power cycling?

Yes, the MAX6373KA-T watchdog timer can be disabled dynamically by setting SET2=1, SET1=0, SET0=0 - a configuration explicitly defined in Table 1 and confirmed in the Applications Information section. When disabled, WDO remains high and the internal timer halts. Re-enabling requires only changing the SET pin states; no power cycle is needed. This feature is validated across all MAX6373KA-T operating conditions and is a documented capability of the MAX6373KA-T.

What is the supply current consumption of the MAX6373KA-T over temperature?

The MAX6373KA-T consumes 8–22µA supply current (ICC), with 8µA typical at +25°C and 10–22µA specified over -40°C to +125°C. These values are measured under no-load conditions and appear in the Electrical Characteristics table of the official datasheet. This ultra-low current enables continuous watchdog supervision in energy-constrained applications such as battery-backed industrial sensors - a verified performance metric for MAX6373KA-T.