Analog Devices Inc. ADM8699ARN

Overview

ADM8699ARN from Analog Devices is a microprocessor supervisory circuit with integrated watchdog timer, precision 4.65 V voltage monitor, guaranteed RESET assertion down to VCC = 1 V, 140–280 ms reset pulse width, and 1.0–2.25 s watchdog timeout period. It serves as a system-level power integrity guardian in embedded controllers requiring fail-safe boot and runtime supervision.

For engineers reviewing the ADM8699ARN datasheet, ADM8699ARN pinout, ADM8699ARN application, or ADM8699ARN equivalent, key selection considerations include its R-8 SOIC package, WDI input compatibility with µP I/O toggling, guaranteed low-VCC reset functionality, and distinction from ADM8698 (no watchdog) and 16-lead variants (additional RESET/WDO outputs).

Technical Context

The ADM8699ARN implements a precision bandgap-based voltage detector with 40 mV hysteresis and a monostable power-on reset generator delivering ≥140 ms active-low RESET pulse. Its watchdog transition detector monitors WDI for edge activity and triggers RESET if no transition occurs within the 1.0–2.25 s timeout window.

Unlike the ADM8698, the ADM8699ARN includes a three-level WDI input that disables the watchdog when floating or held at midsupply, and guarantees functional RESET output down to VCC = 1 V with ≤200 mV sink voltage at 100 µA load - enabling robust brown-out recovery in low-power microcontroller systems.

Key Specifications

Pinout & Package

ADM8699ARN is housed in an 8-pin SOIC (R-8) package per JEDEC MS-012, with 1.27 mm pitch, 5.0 mm × 6.2 mm body, and gull-wing leads. Pin 1 marked by notch or dot.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX699ESA+ and TPS3823-46DBVR, the ADM8699ARN uniquely combines guaranteed sub-1.5 V reset assertion, integrated watchdog with float-disable, and industrial temperature rating - making it the only option among the three qualified for safety-critical, low-voltage-recovery µP supervision.

Availability

ADM8699ARN is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, medical diagnostic instrumentation, and telecom remote terminal units requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ADM8699ARN 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

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, communications, automotive, and healthcare markets since 1965.

The ADM8698/ADM8699 product line was designed specifically for robust, single-chip power supervision and watchdog monitoring in 5 V microprocessor systems - emphasizing fail-safe reset generation, low-VCC operability, and noise-immune timing.

FAQ

What is the function of the WDI pin on the ADM8699ARN?

The WDI (Watchdog Input) pin on the ADM8699ARN monitors microprocessor activity by detecting transitions (low-to-high or high-to-low). Each edge resets the 1.0–2.25 s watchdog timer; failure to toggle within that window forces RESET low. The ADM8699ARN WDI is a three-level input - left floating or driven to midsupply disables the watchdog function entirely, offering flexible configuration without external components.

Does the ADM8699ARN provide RESET assertion when VCC drops below 2 V?

Yes, the ADM8699ARN guarantees functional RESET output down to VCC = 1 V, with RESET remaining logic low and sinking current reliably even at that level. At VCC = 1 V, the ADM8699ARN delivers ≤200 mV output voltage while sinking 100 µA - ensuring the connected microprocessor stays held in reset during deep brown-out conditions where other supervisors would release prematurely.

How does the ADM8699ARN differ from the ADM8698ARN?

The ADM8699ARN includes a functional WDI input and internal watchdog timer logic absent in the ADM8698ARN. Both share identical voltage monitoring (4.65 V threshold), reset timing (140–280 ms), and package (R-8 SOIC), but only the ADM8699ARN asserts RESET in response to watchdog timeout. The ADM8699ARN datasheet explicitly states "*WDI (ADM8699 ONLY)" in functional diagrams and pin descriptions, confirming this is a hardware-differentiated variant.

What is the recommended decoupling for the ADM8699ARN VCC pin?

Analog Devices specifies a 0.1 µF ceramic capacitor placed as close as possible to the VCC pin of the ADM8699ARN to suppress high-frequency noise and stabilize the internal voltage reference. This capacitor mitigates transient-induced false resets and ensures accurate threshold detection, especially under fast-rising or noisy power supply conditions - a requirement explicitly noted in the "Circuit Information" section of the ADM8699ARN datasheet.

Is the ADM8699ARN pin-compatible with the MAX699 in the same SOIC-8 package?

No, the ADM8699ARN is not pin-compatible with the MAX699 in SOIC-8. While both are 8-pin SOIC devices monitoring 4.65 V, the ADM8699ARN assigns Pin 4 to WDI and Pins 5–7 to NC, whereas the MAX699 uses Pin 4 for RESET and has different internal pin mapping. The ADM8699ARN datasheet shows distinct pin configurations and functional block diagrams, and no documentation supports direct substitution without PCB modification.