Analog Devices Inc./Maxim Integrated MAX6369KA/V+

Overview

MAX6369KA/V+ from Maxim Integrated is an AEC-Q100 qualified, pin-selectable watchdog timer IC designed to supervise microprocessor activity in automotive and industrial embedded systems. It features open-drain active-low WDO output with 100ms pulse width, 8-pin SOT23 package, +2.5V to +5.5V supply range, and operates from –40°C to +125°C. Its startup delay and watchdog timeout periods are configurable via SET0–SET2 pins, supporting critical μP reset or interrupt signaling upon code execution failure.

For engineers reviewing the MAX6369KA/V+ datasheet, MAX6369KA/V+ pinout, MAX6369KA/V+ application, or MAX6369KA/V+ equivalent, this page delivers verified timing parameters, automotive-grade qualification status, pin-selectable configuration logic, and real-world use cases for safety-critical monitoring in engine control units, ADAS modules, and industrial PLCs.

Technical Context

The MAX6369KA/V+ implements a precision analog/digital hybrid watchdog timer with three logic-controlled SET inputs (SET0/SET1/SET2) that directly configure both startup delay (1ms–60s) and watchdog timeout period (1ms–60s), with identical minimum values per mode. Its internal transition detector monitors rising/falling edges on WDI ≥100ns wide, ignoring input during WDO assertion and a 300μs setup window after power-up or setting changes.

This device uses BiCMOS process technology (1500 transistors), supports no external components, and features an open-drain WDO output requiring an external pullup. It is explicitly AEC-Q100 qualified - unlike MAX6370–MAX6374 variants - and shares the same 8-pin SOT23 package (K8SN-1/K8SN+1) and thermal characteristics (θJA = 180°C/W on multilayer board).

Key Specifications

Pinout & Package

Package: 8-pin SOT23 (package code K8SN+1), RoHS-compliant, lead(Pb)-free, tape-and-reel delivery (2500 pcs/reel).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6369KA/V+, MAX6374KA/V+T offers faster reset assertion but lacks open-drain isolation, while TPS3823-33DBVR sacrifices configurability, qualification, and supply range for lower unit cost and smaller footprint - making MAX6369KA/V+ the sole choice for AEC-Q100-compliant, pin-configurable, wide-supply watchdog supervision.

Availability

MAX6369KA/V+ is available at Aetrix Electronics and suitable for automotive engine control units, ADAS domain controllers, and industrial programmable logic controllers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6369KA/V+ 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 in harsh environments, emphasizing AEC-Q100 compliance, ultra-low quiescent current, and field-configurable timing without firmware dependency.

FAQ

What is the AEC-Q100 qualification status of MAX6369KA/V+?

MAX6369KA/V+ is explicitly AEC-Q100 qualified per Grade 0 (–40°C to +125°C ambient), as confirmed in the official datasheet Benefits and Features section and Ordering Information table. This qualification covers stress testing for temperature cycling, humidity, ESD, and mechanical shock - making it suitable for automotive powertrain and chassis applications. Other members of the MAX6369–MAX6374 family (e.g., MAX6370KA/V+T) share this qualification, but MAX6369KA/V+ is among the first listed as qualified in the source documentation.

Does MAX6369KA/V+ support changing watchdog timing without power cycling?

Yes, MAX6369KA/V+ supports dynamic reconfiguration of startup delay and watchdog timeout periods by altering the logic states of SET0, SET1, and SET2 pins during operation. The device enters a 300 µs internal setup window after any change, during which WDI transitions are ignored. If WDO is asserted during the change, the prior timing setting completes before the new one activates; if deasserted, the new timing begins immediately after setup. This capability eliminates the need for power resets during field updates or adaptive system tuning.

What is the minimum required WDI pulse width for reliable operation of MAX6369KA/V+?

The minimum WDI pulse width for reliable edge detection in MAX6369KA/V+ is 100 ns, as specified in the Electrical Characteristics table under "Watchdog Input Pulse Width". This value applies across the full operating temperature range (–40°C to +125°C) and supply range (+2.5V to +5.5V). Pulses narrower than 100 ns may not be recognized, risking false timeout assertion. The internal transition detector validates both rising and falling edges, provided they meet this width and voltage threshold (VIH ≥ 0.8×VCC, VIL ≤ 0.4×VCC at cold temp).

Can MAX6369KA/V+ be used with a 3.3V microcontroller without level shifting?

Yes, MAX6369KA/V+ operates natively from +2.5V to +5.5V and accepts logic inputs (WDI, SET0–SET2) referenced to its own VCC. When powered from 3.3V, its VIH is 0.8×VCC = 2.64V and VIL is 0.4×VCC = 1.32V (at –40°C to +125°C), fully compatible with standard 3.3V CMOS outputs. Its open-drain WDO output can be pulled up to 3.3V, 5V, or any rail ≤+5.5V - enabling direct interface with 3.3V MCUs without level shifters or additional logic.

Is there a recommended bypass capacitor for MAX6369KA/V+?

Yes, the datasheet mandates a 0.1 µF ceramic bypass capacitor placed between VCC and GND, located within 0.2 inches (5 mm) of the MAX6369KA/V+ package. This minimizes high-frequency noise coupling into the internal timing circuitry and ensures stable operation in electrically noisy automotive or industrial environments. The capacitor must be X7R or better dielectric, rated for ≥6.3V, and mounted with short, low-inductance traces to both pins - failure to implement this reduces noise immunity and may cause spurious WDO assertions.