Analog Devices Inc. ADM693AARWZ-REEL

Overview

ADM693AARWZ-REEL from Analog Devices is a microprocessor supervisory circuit integrating voltage monitoring, watchdog timer, battery backup switchover, chip enable gating, and power-fail detection. It provides 4.4 V ±3% reset threshold, 200 ms or adjustable reset timeout, 100 ms/1.6 s selectable watchdog timeout, and automatic VCC/VBATT switching to VOUT with ≤0.75 Ω on-resistance. It is used in industrial controllers and automotive ECUs requiring reliable brownout protection and RAM write safeguarding.

For engineers reviewing the ADM693AARWZ-REEL datasheet, ADM693AARWZ-REEL pinout, ADM693AARWZ-REEL application, or ADM693AARWZ-REEL equivalent, key selection criteria include its 4.4 V reset threshold compatibility with ±10% 5 V supplies, 0.04 µA battery-backup supply current, dual RESET outputs (push-pull and open-drain), and integrated CEIN/CEOUT gating for CMOS RAM write protection.

Technical Context

The ADM693AARWZ-REEL implements a dual-threshold voltage detector (4.4 V nominal, 15 mV hysteresis) with internal 200 ms reset timeout generator and configurable watchdog timer using either internal oscillator (100 ms or 1.6 s) or external clock/capacitor. Its battery switchover uses PMOS (VCC→VOUT) and NMOS (VBATT→VOUT) switches with validated 250 mA VCC-source and 10 mA VBATT-source capability.

Chip enable gating features 6–10 ns propagation delay, 40–150 Ω on-resistance, and automatic CEOUT high assertion during reset. The 1.25 V PFI comparator drives PFO with 25 µs response and supports hysteresis via external feedback - all operating down to VCC = 1 V and across –40°C to +85°C.

Key Specifications

Pinout & Package

ADM693AARWZ-REEL is housed in a 16-lead wide-body SOIC (R-16W) package, 7.5 mm × 10.3 mm, with standard 1.27 mm pitch and gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX693AESA+ and TPS3823-44DBVR, ADM693AARWZ-REEL delivers integrated battery switchover control, dual RESET polarity, and CE gating - eliminating 3–5 discrete components and reducing PCB area by ≥12 mm² in full-featured µP supervision designs.

Availability

ADM693AARWZ-REEL is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, and medical infusion pumps requiring stable component supply, long-lifecycle support, and guaranteed parametric compliance across temperature.

Supply support for ADM693AARWZ-REEL 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 ADM69x family was designed specifically for robust microprocessor system supervision - integrating reset, watchdog, battery switchover, CE gating, and power-fail warning in a single 16-pin SOIC to reduce system complexity and improve reliability.

FAQ

What is the reset threshold voltage of the ADM693AARWZ-REEL and how does it differ from the ADM691A?

The ADM693AARWZ-REEL has a guaranteed reset threshold of 4.25 V to 4.50 V (typical 4.4 V ±3%), making it compatible with 5 V ±10% power supplies. In contrast, the ADM691A specifies 4.5 V to 4.75 V (typical 4.65 V), targeting 5 V +10%/−5% rails. This difference ensures ADM693AARWZ-REEL remains asserted during wider supply excursions common in automotive and industrial environments where the ADM693AARWZ-REEL is deployed.

Can the ADM693AARWZ-REEL operate with VCC below 4.4 V and still provide functional outputs?

Yes - the ADM693AARWZ-REEL remains fully operational down to VCC = 1 V. During brownout, RESET stays low, LOW LINE goes low, and CEOUT is forced high to protect memory. Battery switchover activates when VCC falls below VBATT − 0.03 V, and VOUT continues supplying backed-up logic. The ADM693AARWZ-REEL's ability to function at 1 V ensures deterministic behavior during deep undervoltage events where many supervisors cease operation.

How is the watchdog timeout period configured on the ADM693AARWZ-REEL?

The ADM693AARWZ-REEL watchdog timeout is selected using OSC SEL and OSC IN pins. With OSC SEL floating and OSC IN grounded, the short timeout of 100 ms is enabled (except immediately after reset, which defaults to 1.6 s). With both pins floating, the long timeout of 1.6 s is active. For adjustable timing, OSC SEL is pulled low and OSC IN is driven by an external clock or capacitor - enabling precise timeout tuning without additional components.

Does the ADM693AARWZ-REEL support external battery charging, and what is the recommended configuration?

Yes - the ADM693AARWZ-REEL supports rechargeable battery backup. To avoid discharge during power-down, the charging resistor must connect to VOUT (not VCC), as VOUT remains powered by VBATT when VCC fails. This configuration ensures continuous trickle charge to NiMH or Li-ion cells while preventing reverse current flow. The ADM693AARWZ-REEL's battery standby current of 0.04 µA minimizes self-discharge impact on small-capacity cells.

What is the purpose of the dual RESET outputs (pin 15 and pin 16) on the ADM693AARWZ-REEL?

Pin 15 (RESET) is a push-pull active-low output directly compatible with µPs requiring a driven low reset signal. Pin 16 (RESET) is an open-drain active-high output requiring an external pull-up; it provides the logical inverse for processors that lack active-low reset inputs. This dual-output architecture eliminates level translators and supports mixed-voltage systems - a design feature confirmed in the ADM693AARWZ-REEL functional block diagram and pin descriptions.