Analog Devices Inc. ADM699ANZ

Overview

ADM699ANZ from Analog Devices is a microprocessor supervisory circuit with integrated watchdog timer, precision 4.65 V voltage monitor, and guaranteed RESET assertion down to VCC = 1 V. It monitors +5 V power supplies in embedded systems, asserts active-low RESET during power-up/down and brown-out events, and triggers reset if WDI input fails to toggle within 1.6 s (typ). Used in automotive ECUs and industrial controllers for fail-safe power sequencing.

For engineers reviewing the ADM699ANZ datasheet, ADM699ANZ pinout, ADM699ANZ application, or ADM699ANZ equivalent, key selection criteria include its 4.65 V threshold hysteresis (40 mV), 140–280 ms reset pulse width, watchdog timeout tolerance (1.0–2.25 s), low 0.6 mA supply current, and guaranteed operation at VCC = 1 V - critical for robust boot integrity in safety-critical systems.

Technical Context

The ADM699ANZ implements a precision bandgap-based voltage detector with 40 mV hysteresis to reject VCC transients, and a monostable-based power-on reset generator ensuring ≥140 ms RESET assertion after VCC crosses 4.65 V. Its watchdog circuit uses edge-triggered transition detection on WDI to reset the 1.6 s timeout timer on every high-to-low or low-to-high edge.

Unlike the ADM698, the ADM699ANZ adds a dedicated WDI input and supports watchdog-enabled reset assertion - but only in DIP/SOIC variants with explicit WDI pin assignment. The ADM699ANZ's RESET output remains functional down to 1 V VCC, enabling reliable hold-off during deep undervoltage recovery, while its open-drain outputs drive standard TTL/CMOS logic loads.

Key Specifications

Pinout & Package

ADM699ANZ is supplied in an 8-pin plastic DIP (N-8) package with 0.3-inch body width and through-hole mounting. Pin 1 is marked by notch or dot; pins are numbered counterclockwise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX699CPD+ and TPS3823-46DBVR, the ADM699ANZ uniquely combines guaranteed 1 V operation, integrated watchdog with edge-triggered WDI, and industrial-grade temperature validation - making it the only option among the three qualified for automotive and safety-critical reset assurance.

Availability

ADM699ANZ is available at Aetrix Electronics and suitable for automotive engine control units, industrial PLC mainboards, and medical infusion pump controllers requiring stable component supply across extended lifecycle programs.

Supply support for ADM699ANZ 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 is a global semiconductor leader specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision measurement and control systems.

The ADM698/ADM699 product line was engineered specifically for robust microprocessor power supervision in harsh environments - delivering guaranteed reset behavior at ultra-low VCC and deterministic watchdog response for mission-critical embedded applications.

FAQ

What is the function of the WDI pin on the ADM699ANZ?

The WDI (Watchdog Input) pin on the ADM699ANZ is an edge-sensitive input that resets the internal 1.6 s watchdog timer on every high-to-low or low-to-high transition. If no transition occurs within the timeout window, ADM699ANZ asserts RESET low. When left floating or driven to midsupply (~2.5 V), the watchdog is disabled - allowing flexible configuration without external components.

Does the ADM699ANZ provide both active-high and active-low reset outputs?

No - the ADM699ANZ in the 8-pin DIP package (N-8) provides only the active-low open-drain RESET output. The active-high RESET and WDO outputs are exclusive to the 16-lead SOIC variants (e.g., ADM699AR). The ADM699ANZ pinout confirms RESET is the sole reset signal, with no complementary or watchdog status output pins present.

What is the minimum VCC voltage at which ADM699ANZ guarantees RESET assertion?

The ADM699ANZ guarantees RESET remains asserted (low) down to VCC = 1 V, as verified in the datasheet's "RESET Output Voltage (VCC = 1 V)" specification (200 mV max at 10 µA sink). This ensures the connected microprocessor stays reliably held in reset during deep brown-out recovery - a key differentiator versus alternatives that lose reset control below 2.5 V.

Can the ADM699ANZ be used with a 3.3 V microprocessor system?

The ADM699ANZ is designed for +5 V VCC operation and specifies performance only across 3.0 V to 5.5 V supply range. While it may power up at 3.3 V, its 4.65 V reset threshold is incompatible with 3.3 V rail monitoring. For 3.3 V systems, Analog Devices recommends the ADM6315-33 or similar 3.3 V-specific supervisors - the ADM699ANZ is not rated or characterized for 3.3 V use.

How does the ADM699ANZ handle noise on the VCC line?

The ADM699ANZ incorporates 40 mV of built-in hysteresis on its 4.65 V reset threshold to reject noise-induced false triggering. Additionally, the datasheet mandates a 0.1 µF ceramic capacitor at the VCC pin to suppress high-frequency transients. These dual measures ensure stable reset behavior even in electrically noisy environments like automotive or industrial motor-control applications.