Analog Devices Inc. ADM802LARNZ-REEL

Overview

ADM802LARNZ-REEL from Analog Devices is a precision microprocessor supervisory circuit in SO-8 package, providing active-low reset (RESET), battery switchover, 1.6 s watchdog timer, and 1.25 V power-fail comparator. It asserts reset at 4.65 V ±50 mV, operates down to 1 V VCC, and delivers 100 µA quiescent current - used for reliable power monitoring in embedded controllers and industrial instrumentation.

For engineers reviewing the ADM802LARNZ-REEL datasheet, ADM802LARNZ-REEL pinout, ADM802LARNZ-REEL application, or ADM802LARNZ-REEL equivalent, key selection criteria include guaranteed reset assertion below 1 V VCC, ±2% PFI accuracy, battery switchover hysteresis of 40 mV, and compatibility with CMOS RAM backup in space-constrained SOIC layouts.

Technical Context

The ADM802LARNZ-REEL integrates four core functions on a single die: a precision bandgap-based reset generator with 4.65 V threshold, a transition-detecting watchdog timer with 1.6 s timeout, an internal PMOS battery switchover switch (dropout <20 mV at 250 µA), and a 1.25 V reference-based power-fail comparator with ±2% accuracy on PFI input.

Its RESET output remains functional down to VCC = 1 V, ensuring deterministic microprocessor hold during brownout; the WDI input accepts three-level logic (floating disables watchdog), and PFO provides open-drain low-active warning synchronized to PFI crossing 1.25 V.

Key Specifications

Pinout & Package

ADM802LARNZ-REEL is housed in an 8-lead SOIC (SO-8) package, 3.9 mm × 4.9 mm, with standard 1.27 mm pitch and gull-wing leads. Pin 1 is marked by a beveled corner or dot; device orientation follows JEDEC MS-012.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX802LCSA+, ADM802LARNZ-REEL delivers tighter reset threshold control and guaranteed sub-2 V operation; versus TPS3808G18DBVR, it consolidates four functions into one SO-8 footprint - reducing board area by >30% and eliminating three discrete support components.

Availability

ADM802LARNZ-REEL is available at Aetrix Electronics and suitable for industrial automation, medical device, and automotive telematics applications requiring stable component supply, long-term lifecycle assurance, and guaranteed parametric performance across –40°C to +85°C.

Supply support for ADM802LARNZ-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, founded in 1965 and headquartered in Wilmington, MA.

The ADM802L series belongs to Analog Devices' microprocessor supervisory product line, designed specifically for robust power monitoring and fail-safe system recovery in mission-critical embedded systems.

FAQ

What is the guaranteed minimum operating VCC for reset assertion in ADM802LARNZ-REEL?

The ADM802LARNZ-REEL guarantees RESET assertion down to VCC = 1.0 V across the full industrial temperature range (–40°C to +85°C). This ensures the microprocessor remains held in reset during deep brownout events where other supervisors may release prematurely. The specification is verified per Analog Devices' datasheet Rev. 0, Section "RESET THRESHOLD".

Does ADM802LARNZ-REEL support automatic battery switchover, and what is its dropout voltage?

Yes, ADM802LARNZ-REEL supports automatic battery switchover between VCC and VBATT. When VCC falls below VBATT by 20 mV, the internal PMOS switch connects VBATT to VOUT. In battery backup mode, VOUT = VBATT – 0.002 V at 250 µA load - confirming sub-2 mV dropout, enabling stable RAM retention without external regulators.

What is the accuracy of the power-fail comparator (PFI) in ADM802LARNZ-REEL, and how is it specified?

The ADM802LARNZ-REEL guarantees ±2% accuracy on its 1.25 V internal reference used for PFI comparison. Per datasheet Rev. 0, Table "POWER FAIL DETECTOR", PFI threshold is 1.225 V to 1.275 V at TA = 25°C, and this tolerance holds across temperature and supply variations - enabling precise VT setting without trimming.

Can the watchdog timer in ADM802LARNZ-REEL be disabled, and how?

Yes, the watchdog timer in ADM802LARNZ-REEL can be disabled by leaving the WDI pin floating or connecting it to a high-impedance (three-state) logic output. Datasheet Rev. 0 explicitly states: "The watchdog timer may be disabled if WDI is left floating or is connected to a high impedance three stated logic output." No pull-up/down resistors are required.

What package type and lead finish does ADM802LARNZ-REEL use, and is it RoHS compliant?

ADM802LARNZ-REEL uses an 8-lead SOIC (SO-8) package with lead-free (Pb-free) matte tin finish, compliant with RoHS Directive 2011/65/EU. The "Z" suffix in the part number denotes RoHS-compliant packaging, and the device meets Analog Devices' environmental specifications per their official product change notices.