Analog Devices Inc. ADM9690ARNZ

Overview

ADM9690ARNZ from Analog Devices is a precision power supply and watchdog timer monitoring circuit for 5 V microprocessor systems. It features a 4.31 V voltage monitor with 30 mV hysteresis, dual independent reset outputs (RESET(1) = 50 ms, RESET(2) = 60 ms), and selectable watchdog timeout periods (0.75 ms to 25 ms via SEL1/SEL2). It operates down to 2 V VCC and is used in embedded controllers requiring reliable power-up and runtime fault detection.

For engineers reviewing the ADM9690ARNZ datasheet, ADM9690ARNZ pinout, ADM9690ARNZ application, or ADM9690ARNZ equivalent, key selection criteria include guaranteed reset threshold accuracy (4.2–4.42 V), industrial temperature range (–40°C to +85°C), SOIC-8 package compatibility, and dual-reset timing coordination for µP and auxiliary circuitry sequencing.

Technical Context

The ADM9690ARNZ integrates two independent monitoring functions: a precision voltage comparator on VMON and a transition-triggered watchdog timer on WDI. The voltage monitor asserts both resets when VMON falls below 4.31 V (±110 mV), with hysteresis ensuring noise immunity. RESET(1) deasserts after 50 ms and RESET(2) after 60 ms post-threshold recovery.

The watchdog uses edge-sensitive detection on WDI and supports four discrete timeout periods (0.75/1.5/12.5/25 ms) selected by SEL1 and SEL2 logic levels. It restarts on any WDI transition after RESET(1) goes high - whether triggered by power fail or watchdog timeout - enabling robust stall detection without external clock sources.

Key Specifications

Pinout & Package

The ADM9690ARNZ is housed in an 8-lead narrow SOIC (SO-8) package, 3.9 mm × 4.9 mm body, 1.27 mm pitch, compliant with JEDEC MS-012.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar power supply and watchdog monitoring applications.

Compared with MAX6326US43D3+ and TPS3823-43DBVR, the ADM9690ARNZ uniquely delivers dual-timed reset outputs and four selectable watchdog periods in SOIC-8 - enabling precise coordination of µP and peripheral startup while supporting tight-loop firmware supervision.

Availability

ADM9690ARNZ is available at Aetrix Electronics and suitable for industrial controllers, embedded printers, and intelligent instruments requiring stable component supply, long-term lifecycle support, and guaranteed performance across –40°C to +85°C.

Supply support for ADM9690ARNZ 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, founded in 1965 and headquartered in Wilmington, MA.

The ADM9690ARNZ belongs to Analog Devices' power monitoring and supervisory IC product line, designed specifically for robust, low-power, and timing-precise reset generation in microprocessor-based industrial and embedded systems.

FAQ

What is the exact reset voltage threshold of the ADM9690ARNZ?

The ADM9690ARNZ has a nominal reset voltage threshold of 4.31 V, with a guaranteed range of 4.2 V to 4.42 V over the industrial temperature range (–40°C to +85°C). This threshold applies to the VMON input and is specified with 30 mV hysteresis to prevent chatter during slow supply transitions. The ADM9690ARNZ maintains this accuracy without external calibration or trimming components.

How does the ADM9690ARNZ handle watchdog timeout and power-fail reset simultaneously?

When either condition occurs - VMON dropping below threshold or WDI inactivity exceeding the selected timeout - both RESET(1) and RESET(2) go active low simultaneously. RESET(1) remains low for exactly 50 ms and RESET(2) for 60 ms, regardless of trigger source. The watchdog timer restarts automatically when RESET(1) goes high, ensuring consistent behavior whether the reset originated from power failure or software stall. This unified timing is intrinsic to the ADM9690ARNZ design.

Can the ADM9690ARNZ operate with a 3.3 V supply?

No - the ADM9690ARNZ is specified for 4.3 V to 5.5 V VCC operation and is not rated for 3.3 V supply rails. Its internal voltage reference and comparator circuitry are optimized for 5 V systems. Attempting to power the ADM9690ARNZ from 3.3 V may result in undefined reset behavior or failure to assert outputs. For 3.3 V applications, consider Analog Devices' ADM63xx family or compatible 3.3 V supervisors.

What is the minimum pulse width required on WDI to reset the watchdog timer in the ADM9690ARNZ?

The ADM9690ARNZ requires a minimum WDI input pulse width of 100 ns to register a valid edge transition and restart the watchdog timer. This specification holds for both rising and falling edges under standard test conditions (VIL = 0.4 V, VIH = 3.5 V). The ADM9690ARNZ's edge-detection circuitry ensures reliable recognition even with short firmware-generated toggles, supporting tight-loop supervision without timing overhead.

Is the ADM9690ARNZ pin-compatible with other Analog Devices supervisory ICs like the ADM690A?

No - the ADM9690ARNZ is not pin-compatible with the ADM690A or other members of the ADM69x family. It features a unique 8-pin SOIC pinout with dedicated SEL1/SEL2 inputs and dual RESET outputs, whereas the ADM690A uses a 8-pin SOIC layout with different signal assignments (e.g., PFI, PFO, MR). Board-level replacement requires schematic and layout revision. The ADM9690ARNZ pinout is fixed per its datasheet and cannot be substituted without hardware modification.