Analog Devices Inc./Maxim Integrated MAX16997AAUA/V+T

Overview

The MAX16997AAUA/V+T from Maxim Integrated is a high-voltage, low-quiescent-current microprocessor supervisory IC designed for automotive power monitoring and fault recovery. It provides single open-drain ENABLE output based on EN input voltage level and WDI watchdog timing, supports 5V–40V input range, delivers 18µA typical supply current at +125°C, and operates across –40°C to +125°C - enabling reliable fail-safe control in engine control units and ADAS domain controllers.

For engineers reviewing the MAX16997AAUA/V+T datasheet, MAX16997AAUA/V+T pinout, MAX16997AAUA/V+T application, or MAX16997AAUA/V+T equivalent, key selection criteria include its EN-triggered watchdog startup with 8× initial timeout extension, car-battery-compatible EN input threshold (1.235V), capacitor-adjustable watchdog period (tWP), AEC-Q100 qualification, and absence of RESET output - distinguishing it from dual-output MAX16998 variants.

Technical Context

The MAX16997AAUA/V+T implements a single-output supervisory architecture centered on EN input monitoring and WDI edge detection. Its watchdog timer initiates only when EN rises above 1.235V, and the first timeout period is extended to 8×tWP - preventing false triggers during power-up sequencing. The ENABLE output asserts after three consecutive WDI faults and remains active until three valid falling edges occur.

No reset comparator or RESET output is integrated; instead, system-level reset coordination relies on external circuitry triggered by ENABLE. All timing functions (tWP, tWP-initial) are set via external SWT capacitor, while EN threshold and leakage are tightly specified (±120mV over temperature, 0.1µA max leakage), ensuring robust operation in noisy automotive environments.

Key Specifications

Pinout & Package

MAX16997AAUA/V+T is housed in an 8-pin lead(Pb)-free µMAX® package (3mm × 3mm), RoHS-compliant and qualified to AEC-Q100. Pin 1 is IN (power input), Pin 2 is EN (enable comparator input), Pins 3 and 7 are no-connect, Pin 4 is SWT (watchdog timeout capacitor), Pin 5 is GND, Pin 6 is WDI (watchdog input), Pin 8 is ENABLE (open-drain output).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX16998AAUA/V+, the MAX16997AAUA/V+T eliminates RESET output and RESETIN input to reduce pin count and simplify design, while retaining full EN-triggered watchdog supervision - making it optimal for new automotive platforms prioritizing compactness and functional safety through ENABLE-driven redundancy.

Availability

MAX16997AAUA/V+T is available at Aetrix Electronics and suitable for automotive engine control units, ADAS domain controllers, body control modules, and electric power steering systems requiring stable component supply across extended temperature and long product lifecycles.

Supply support for MAX16997AAUA/V+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 MAX16997/MAX16998 family was engineered specifically for high-voltage automotive supervisory functions - delivering ultra-low quiescent current, AEC-Q100 qualification, and flexible watchdog timing to meet ASIL-B system-level safety goals.

FAQ

Does the MAX16997AAUA/V+T provide a RESET output signal?

No, the MAX16997AAUA/V+T does not include a RESET output. It generates only a single open-drain ENABLE signal based on EN voltage level and WDI watchdog timing. For designs requiring both RESET and ENABLE, the MAX16998AAUA/V+T variant must be selected. The MAX16997AAUA/V+T's architecture intentionally omits RESET to reduce pin count and simplify integration in systems where external reset generation is handled separately.

What is the function of the EN pin on the MAX16997AAUA/V+T?

The EN pin on the MAX16997AAUA/V+T serves as a high-impedance enable comparator input with a factory-trimmed 1.235V threshold. When EN rises above this voltage, the internal watchdog timer starts counting. Each subsequent EN rise from below-to-above threshold triggers an extended 8×tWP initial timeout - ensuring reliable operation during power-up sequencing. EN must be actively driven; floating EN causes undefined behavior.

How is the watchdog timeout period set on the MAX16997AAUA/V+T?

The watchdog timeout period (tWP) on the MAX16997AAUA/V+T is set by connecting an external capacitor between the SWT pin and GND. Using the formula CSWT = (tWP × IRAMP_SWT) / (4 × VRAMP), with IRAMP_SWT = 500nA and VRAMP = 1.235V, tWP can be adjusted from 6.8ms (680pF) to 217ms (22nF). Shorting SWT to GND disables the watchdog function entirely.

Is the MAX16997AAUA/V+T qualified for automotive applications?

Yes, the MAX16997AAUA/V+T is AEC-Q100 qualified (Grade 0) and fully specified over –40°C to +125°C. The "/V" suffix explicitly denotes automotive qualification, and the device meets stringent automotive reliability, thermal, and EMI immunity requirements - making it suitable for under-hood and safety-critical applications including engine control, ADAS, and EPS.

What is the maximum allowable voltage on the ENABLE output of the MAX16997AAUA/V+T?

The ENABLE output of the MAX16997AAUA/V+T is an open-drain structure rated for a maximum pullup voltage of 28V. This allows direct interfacing with higher-voltage domains such as 12V or 24V automotive logic rails. The output sinks up to 5mA while maintaining VOL ≤ 0.4V, and leakage current remains below 0.1µA when deasserted at 14V.

Can the MAX16997AAUA/V+T be used in systems without a dedicated WDI signal?

No - the MAX16997AAUA/V+T requires an active WDI signal to perform watchdog supervision. Leaving WDI unconnected or floating will cause improper operation, as the device expects timed falling edges to clear the watchdog timer. If no WDI source exists, the watchdog must be disabled by shorting SWT to GND, reducing the IC to an EN-threshold detector only - but ENABLE assertion then becomes impossible.