Analog Devices Inc. ADM697ARZ

Overview

ADM697ARZ from Analog Devices is a microprocessor supervisory circuit with integrated chip-enable gating, 1.3 V low-line detection, adjustable watchdog timer (100 ms / 1.6 s), power-fail monitoring, and reset assertion down to 1 V VCC. It serves as a system-level power integrity guardian in embedded controllers and battery-backed memory systems.

For engineers reviewing the ADM697ARZ datasheet, ADM697ARZ pinout, ADM697ARZ application, or ADM697ARZ equivalent, this page delivers verified functional identity, exact pin roles, real-world timing behavior, CE gating performance (5 ns propagation), and validated alternative options for RAM write protection and power fail supervision.

Technical Context

The ADM697ARZ implements dual independent comparators (LLIN vs. 1.3 V reference; PFI vs. 1.3 V), a configurable oscillator (internal or external clock/capacitor), and a transition-sensitive watchdog timer that resets on each WDI edge. Its CEIN-to-CEOUT path features active-high gating with automatic high-Z override when LLIN falls below threshold.

Reset generation uses a dedicated timebase with 50 ms guaranteed pulse width after LLIN recovery; watchdog timeout defaults to 1.6 s post-reset then switches to 100 ms after first WDI transition. Battery backup logic is absent (ADM696-only), confirming ADM697ARZ's exclusive focus on CE control and voltage supervision-not power switchover.

Key Specifications

Pinout & Package

ADM697ARZ is housed in a 16-lead SOIC (R-16) package with 1.27 mm pitch, RoHS-compliant, and rated for –40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX697CSA+ and TPS3808G33DBVR, ADM697ARZ uniquely integrates 5 ns CE gating with dual-threshold voltage supervision, enabling deterministic write blocking during brownout - a capability absent in both alternatives and essential for systems storing mission-critical data in battery-backed memory.

Availability

ADM697ARZ is available at Aetrix Electronics and suitable for industrial PLC controllers, medical diagnostic instruments, automotive body control modules, smart energy meters, and critical microprocessor power monitoring applications requiring stable component supply and long-term lifecycle support.

Supply support for ADM697ARZ 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 with precision power, sensing, and timing solutions.

The ADM697ARZ belongs to Analog Devices' microprocessor supervisory IC product line, engineered specifically for systems demanding robust memory write protection, predictive power-fail detection, and sub-1 V reset assurance in harsh operating environments.

FAQ

What is the primary function of the ADM697ARZ in a microprocessor system?

The ADM697ARZ serves as a supervisory circuit focused on memory integrity and power reliability. Its core functions include monitoring supply voltage via LLIN and PFI inputs, generating precise reset signals (active-low and active-high), providing watchdog timer supervision, and-uniquely-gating the CEIN signal to CEOUT with 5 ns delay to prevent writes to battery-backed RAM during brownout conditions. This makes ADM697ARZ especially valuable where data corruption must be avoided during power transitions.

Does the ADM697ARZ support battery backup switching like the ADM696?

No, the ADM697ARZ does not support battery backup switching. That function is exclusive to the ADM696 variant. The ADM697ARZ omits VBATT, VOUT, and BATT ON pins entirely - its pinout and internal architecture are optimized for chip-enable gating and voltage supervision only. If battery switchover is required, the ADM696ARZ (or equivalent) must be selected instead of ADM697ARZ.

How does the CE gating feature of the ADM697ARZ protect memory during power failure?

The ADM697ARZ monitors the LLIN input against a 1.3 V reference. When LLIN drops below threshold, the internal logic immediately forces CEOUT high - regardless of CEIN state - blocking write access to connected CMOS RAM or EEPROM. This occurs with only 5 ns propagation delay, ensuring no spurious writes occur during the earliest phase of supply decay. CEOUT returns to tracking CEIN only after LLIN rises above 1.3 V and remains stable, preserving data integrity without software intervention.

Can the watchdog timeout period of the ADM697ARZ be adjusted, and how?

Yes, the ADM697ARZ watchdog timeout is configurable via the OSC SEL and OSC IN pins. With OSC SEL high or floating, the internal oscillator sets fixed periods: 100 ms (OSC IN low) or 1.6 s (OSC IN high). With OSC SEL low, an external capacitor on OSC IN (e.g., 47 pF) yields ~1.6 s timeout, while an external clock (0–250 kHz) allows precise cycle-based timing (e.g., 1024 or 4096 cycles). All configurations maintain the 1.6 s post-reset default to ensure safe firmware initialization.

What is the minimum VCC voltage at which ADM697ARZ can assert a valid RESET signal?

The ADM697ARZ guarantees RESET assertion down to VCC = 1 V. At this voltage, the RESET output sinks ≤200 mV with 10 µA load, maintaining sufficient noise margin to hold a microprocessor in reset. This specification is verified across temperature and process corners, making ADM697ARZ suitable for applications experiencing deep brownout conditions where other supervisors may release reset prematurely - a critical requirement for fail-safe embedded systems.