Analog Devices Inc. ADM699AR

Overview

ADM699AR from Analog Devices is a microprocessor supervisory circuit with integrated watchdog timer, precision 4.65 V voltage monitor, 140–280 ms reset pulse width, guaranteed RESET assertion down to VCC = 1 V, and WDI/WDO functionality-designed for reliable power-up, brown-out, and software-fault recovery in 5 V embedded systems.

For engineers reviewing the ADM699AR datasheet, ADM699AR pinout, ADM699AR application, or ADM699AR equivalent, this page delivers verified functional identity, SOIC-16 package mapping, watchdog timeout behavior (1.0–2.25 s), reset threshold hysteresis (40 mV), and real-world use cases in automotive controllers and industrial microprocessor systems.

Technical Context

The ADM699AR implements a precision bandgap-based voltage detector with 4.65 V nominal threshold and 40 mV hysteresis to reject supply noise and prevent false resets during transient dips. Its internal monostable ensures minimum 140 ms RESET active time after power-up or brown-out recovery.

As the ADM699 variant in 16-lead SOIC, it adds a three-level watchdog input (WDI) that resets on any edge transition and forces RESET low if idle >1.6 s (typ); WDO provides complementary watchdog status output, active-low when timeout occurs-both functions fully operational across –40°C to +85°C.

Key Specifications

Pinout & Package

ADM699AR is supplied in a 16-lead SOIC (R-16) package with 1.27 mm pitch, 10.3 mm × 7.5 mm body, and thermal impedance θ_JA = 110°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX699CSA+ and TPS3823-46DBVR, the ADM699AR uniquely combines SOIC-16 packaging, dual RESET polarity outputs, and a dedicated WDO* status pin-enabling robust diagnostics and flexible reset interface design without added components.

Availability

ADM699AR is available at Aetrix Electronics and suitable for automotive engine control units, industrial PLC controllers, medical infusion pumps, and telecom line cards requiring stable component supply, long-term lifecycle support, and guaranteed parametric performance over –40°C to +85°C.

Supply support for ADM699AR 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 leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets since 1965.

The ADM698/ADM699 family was engineered specifically for microprocessor system reliability-delivering precision voltage supervision and deterministic watchdog timing in harsh, mission-critical environments.

FAQ

What is the primary function of the ADM699AR in a microprocessor system?

The ADM699AR serves as a dual-function supervisory IC: it monitors the 5 V VCC supply to assert RESET* during power-up, brown-out, or undervoltage conditions, and independently verifies software execution via its WDI input. If WDI is not toggled within ~1.6 s, ADM699AR forces RESET* low and drives WDO* low-ensuring automatic recovery from firmware lockups without external intervention.

Does the ADM699AR require external components to operate?

The ADM699AR operates with minimal external components: only a 0.1 µF ceramic capacitor at VCC is recommended for noise suppression. No external resistors, capacitors, or timing components are needed for reset timing or watchdog functionality-the 140–280 ms reset pulse and 1.0–2.25 s watchdog timeout are internally generated and temperature-compensated.

How does the ADM699AR handle operation at very low VCC voltages?

The ADM699AR guarantees RESET* remains logic-low down to VCC = 1 V (≤200 mV at 10 µA sink), ensuring the microprocessor stays held in reset during deep brown-out or battery-depletion scenarios. This behavior is explicitly characterized and tested-not extrapolated-and enables safe, predictable shutdown before logic corruption occurs.

What is the role of the WDO* pin on the ADM699AR?

The WDO* pin on the ADM699AR is an active-low watchdog status output that goes low whenever the WDI input remains static beyond the timeout period (~1.6 s typ). It returns high at the next WDI edge and also goes high when VCC falls below the reset threshold. This allows external circuitry-such as an FPGA or status LED-to monitor watchdog health independently of the RESET* signal.

Can the ADM699AR watchdog be disabled, and how?

Yes, the ADM699AR watchdog can be disabled by leaving the WDI pin floating or driving it to midsupply (~2.5 V). The WDI input is a three-level comparator: only sustained logic-high or logic-low states trigger the watchdog timer. Midsupply or open-circuit conditions disable timeout monitoring while preserving full voltage supervision functionality of RESET* and RESET.