Analog Devices Inc./Maxim Integrated MAX6369KA+

Overview

MAX6369KA+ 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 and watchdog timeout periods selectable via SET0–SET2 pins - used in automotive ECUs and industrial controllers for fail-safe reset signaling.

For engineers reviewing the MAX6369KA+ datasheet, MAX6369KA+ pinout, MAX6369KA+ application, or MAX6369KA+ equivalent, key selection criteria include its AEC-Q100 qualification (for /V variants), 8-pin SOT23 package, 1ms–60s pin-selectable timeout range, and compatibility with noisy environments requiring robust μP supervision without external components.

Technical Context

The MAX6369KA+ implements a precision analog/digital hybrid watchdog circuit with BiCMOS process technology. Its internal timer clears on every valid rising or falling edge at WDI (≥100ns wide), and asserts WDO low for 100ms if no transition occurs within the selected timeout period after startup delay completion.

Startup delay and watchdog timeout are jointly determined by the logic states of three dedicated SET pins (SET0/SET1/SET2), enabling eight discrete timing configurations without power cycling. The device enters a 300µs internal setup phase after power-up or SET pin changes, during which WDI transitions are ignored.

Key Specifications

Pinout & Package

MAX6369KA+ is housed in an 8-pin SOT23 package (package code K8SN+1, outline 21-0078), measuring 2.9mm × 1.6mm × 1.1mm, RoHS-compliant and lead(Pb)-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6369KA+, MAX6370KA+ offers identical timing control but eliminates external pullup needs via push-pull output, while TPS3808G33DBVR trades configurability for lower power and fixed timing - making MAX6369KA+ optimal for AEC-Q100-requiring, pin-flexible, open-drain-compatible designs.

Availability

MAX6369KA+ is available at Aetrix Electronics and suitable for automotive ECU development, industrial PLC manufacturing, and medical device production requiring stable component supply across extended temperature ranges and long lifecycle commitments.

Supply support for MAX6369KA+ 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 and mixed-signal ICs for demanding industrial, automotive, and communications applications.

The MAX6369–MAX6374 family delivers pin-configurable watchdog supervision targeting safety-critical μP monitoring where flexibility, low power, and AEC-Q100 compliance are mandatory.

FAQ

What is the watchdog output type and drive capability of MAX6369KA+?

The MAX6369KA+ features an open-drain, active-low watchdog output (WDO). It sinks up to 1.2mA at 0.3V (VCC > 2.7V) and requires an external pullup resistor - typically 10kΩ - to the desired logic rail (up to +5.5V). This architecture allows level-shifting and wired-OR configurations not possible with push-pull outputs like those in MAX6370KA+.

How do I configure the startup delay and timeout period on MAX6369KA+?

Configure MAX6369KA+ timing using the three logic inputs SET0, SET1, and SET2, each tied to either VCC or GND. Their combination selects one of eight predefined timing modes - e.g., SET2=LOW/SET1=LOW/SET0=LOW yields 1ms startup delay and 1ms timeout. Full mapping is provided in Table 1 of the MAX6369KA+ datasheet; no programming or firmware is required.

Is MAX6369KA+ qualified for automotive applications?

MAX6369KA+ itself is not AEC-Q100 qualified; however, the identical-die variant MAX6369KA/V+ is explicitly AEC-Q100 qualified for automotive use. Both share the same 8-pin SOT23 package, electrical specifications, and timing behavior - only the test documentation and top-mark differ. For production automotive designs, specify MAX6369KA/V+.

What happens if the WDI signal remains static during normal operation?

If WDI remains continuously HIGH or LOW beyond the selected watchdog timeout period, the MAX6369KA+ asserts WDO low for 100ms. This pulse can trigger a system reset or interrupt. The internal timer resets only on valid rising or falling edges ≥100ns wide - static levels, noise spikes, or sub-100ns glitches are ignored, preventing false timeouts.

Can I change the watchdog timing settings dynamically without resetting MAX6369KA+?

Yes - MAX6369KA+ supports real-time timing reconfiguration. Change SET0–SET2 logic levels while operating; the device enters a 300µs internal setup phase, then adopts the new timing parameters. To avoid spurious timeouts, strobe WDI immediately before changing settings, ensuring the timer is cleared prior to reconfiguration.