Analog Devices Inc. ADM706AR-REEL

Overview

ADM706AR-REEL from Analog Devices is a low-cost microprocessor supervisory circuit designed for 5 V supply monitoring in embedded systems. It provides active-low reset output with 4.40 V threshold, 200 ms reset pulse width, 190 μA quiescent current, and integrated watchdog timer with 1.60 sec timeout-enabling reliable power-up, brownout, and software stall detection in industrial controllers.

For engineers reviewing the ADM706AR-REEL datasheet, ADM706AR-REEL pinout, ADM706AR-REEL application, or ADM706AR-REEL equivalent, key selection criteria include reset threshold accuracy (±0.15 V), guaranteed RESET validity down to 1 V VCC, debounced manual reset input (MR), power-fail comparator interface (PFI/PFO), and SOIC-8 package compatibility with standard PCB layouts.

Technical Context

The ADM706AR-REEL implements a precision voltage monitor with 4.40 V ±0.15 V reset threshold and 40 mV hysteresis, ensuring stable reset assertion during supply transients. Its internal watchdog timer requires WDI toggling every 1.60 sec (±0.65 sec) to prevent timeout-induced WDO assertion.

A dedicated 1.25 V reference powers the PFI comparator, enabling external supply monitoring via resistive dividers; PFO asserts low when PFI drops below 1.25 V (±0.05 V). MR input accepts TTL/CMOS logic or mechanical switch inputs with internal 250 μA pull-up and 150 ns minimum pulse width support.

Key Specifications

Pinout & Package

ADM706AR-REEL is housed in an 8-lead SOIC_N (R-8) package with 1.27 mm lead pitch, JEDEC MS-012-AA compliant outline, and surface-mount footprint compatible with automated assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX706CSA+ and TPS3808G33DBVR, ADM706AR-REEL uniquely combines 5 V system compatibility, integrated PFI/PFO monitoring, and guaranteed sub-1 V reset validity-making it optimal for industrial and medical applications demanding comprehensive supply supervision.

Availability

ADM706AR-REEL is available at Aetrix Electronics and suitable for industrial PLCs, medical diagnostic instruments, telecom remote terminals, and automotive body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ADM706AR-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 ADM705/ADM706 family was engineered specifically for robust microprocessor supervision in harsh environments-delivering precision voltage monitoring, watchdog safety, and power-fail warning in compact SOIC and MSOP packages.

FAQ

What is the reset threshold voltage for ADM706AR-REEL and how tightly is it specified?

The ADM706AR-REEL has a nominal reset threshold of 4.40 V, with a guaranteed range of 4.25 V to 4.50 V over the full industrial temperature range (−40°C to +85°C). This 0.25 V window ensures reliable reset assertion before a 5 V supply falls below the minimum operating voltage of most microcontrollers, while hysteresis of 40 mV prevents chatter near the trip point. The specification is validated per Analog Devices' Rev. H datasheet Table 1.

Does ADM706AR-REEL support watchdog functionality, and what is its timeout behavior?

Yes, ADM706AR-REEL includes a fully integrated watchdog timer with a nominal timeout period of 1.60 seconds. The timer resets on any high-to-low or low-to-high transition at the WDI pin; if no transition occurs within the timeout window, WDO asserts low. The timeout varies from 1.00 sec to 2.25 sec across temperature and supply conditions. WDO can be connected to MR to generate a system reset upon timeout, as documented in Figure 14 and Section "Watchdog Timer (ADM705/ADM706)" of the datasheet.

Can ADM706AR-REEL monitor a second power supply, and how is this implemented?

Yes, ADM706AR-REEL supports secondary supply monitoring via its PFI (Power Fail Input) and PFO (Power Fail Output) pins. A resistive divider scales the target supply (e.g., 12 V, 3.3 V) to ≤1.25 V at PFI; when the scaled voltage drops below the 1.25 V comparator threshold (±0.05 V), PFO goes low. This enables early warning of supply degradation without MCU intervention. Figure 15 and Section "Power Fail Comparator" detail implementation with optional Schottky clamping and hysteresis resistor networks.

What package type and compliance does ADM706AR-REEL use, and is it RoHS-compliant?

ADM706AR-REEL is supplied in an 8-lead Standard Small Outline Package (SOIC_N, R-8) per JEDEC MS-012-AA, with 1.27 mm lead pitch and tape-and-reel packaging for SMT assembly. The "AR" suffix denotes SOIC packaging; the "-REEL" suffix confirms reel delivery. While the base part ADM706AR is not explicitly RoHS-marked in the provided ordering guide, RoHS-compliant versions are designated with "Z" (e.g., ADM706ARZ-REEL), and Analog Devices certifies full RoHS compliance for all current production lots of this family.

How does ADM706AR-REEL behave during deep brownout, and what is its minimum functional VCC?

ADM706AR-REEL guarantees valid RESET output down to VCC = 1.0 V, as confirmed in the Absolute Maximum Ratings table and Typical Performance Characteristics (Figure 6). Below 1 V, internal drive strength diminishes; however, the datasheet recommends adding an external pull-down resistor (Figure 17) to maintain logic-low assertion if required. This sub-1 V operation ensures the microprocessor remains held in reset throughout complete power collapse, preventing erratic execution during undervoltage conditions.