Analog Devices Inc. ADM1232ARN

Overview

ADM1232ARN from Analog Devices is a 5 V microprocessor supervisory circuit in an 8-lead narrow SOIC (R-8) package, featuring adjustable voltage monitoring (4.5 V or 4.75 V trip), programmable strobe timeout (150/600/1200 ms), push-button reset with 20 ms debounce, open-drain RESET and active-high RESET outputs, and operation from −40°C to +85°C. It monitors supply voltage integrity, detects microprocessor lockup via STROBE activity, and supports manual reset in embedded control systems.

For engineers reviewing the ADM1232ARN datasheet, ADM1232ARN pinout, ADM1232ARN application, or ADM1232ARN equivalent, key selection criteria include VCC trip point tolerance (5% or 10%), STROBE timeout configuration via TD pin, dual-reset output topology (push-pull RESET and open-drain RESET), thermal resistance (θJA = 153°C/W), and RoHS-compliant R-8 packaging for space-constrained industrial controllers.

Technical Context

The ADM1232ARN integrates three core supervision functions: precision VCC threshold detection with selectable 5% (4.75 V) or 10% (4.5 V) tolerance via TOLERANCE pin; watchdog-style STROBE monitoring with timeout periods set by TD voltage level (0 V, floating, or VCC); and debounced PB RESET input requiring ≥20 ms low pulse for guaranteed reset assertion. All functions operate without external components.

Its dual-reset architecture provides both active-high RESET (sourcing/sinking up to ±10 mA) and open-drain RESET (requiring external pull-up), enabling flexible interface with diverse microprocessor reset inputs. The device asserts RESET on VCC drop below trip point (50 μs delay), power-up, PB RESET activation, or STROBE timeout - with RESET remaining valid down to VCC = 2.0 V during brownout.

Key Specifications

Pinout & Package

ADM1232ARN is housed in an 8-lead narrow SOIC (R-8) package per JEDEC MS-012-AA, with 1.27 mm lead pitch, 5.00 mm × 3.96 mm body size, and θJA = 153°C/W. Pin 1 is marked by a beveled corner; all NC pins are unconnected and must remain floating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX1232ESA+ and DS1232LPN+, the ADM1232ARN offers configurable STROBE timeout via TD voltage level - enabling precise alignment with processor instruction cycles - while maintaining identical pinout and dual-reset output structure for drop-in replacement in most existing layouts.

Availability

ADM1232ARN is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, medical infusion pumps, and point-of-sale terminals requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ADM1232ARN 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, Inc. is a global semiconductor company specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision instrumentation, industrial automation, and communications systems.

The ADM1232 belongs to Analog Devices' microprocessor supervisory product line, designed specifically to provide robust, component-free power-on reset, supply voltage monitoring, and watchdog functionality for resource-constrained embedded systems operating in harsh environments.

FAQ

What is the exact VCC trip voltage for ADM1232ARN when TOLERANCE is tied to GND?

The ADM1232ARN asserts RESET when VCC falls below 4.75 V (5% tolerance) when TOLERANCE is connected to GND. This value is specified in Table 1 of the Rev. C datasheet with min/typ/max of 4.62 V to 4.74 V at TA = −40°C to +85°C. The ADM1232ARN maintains this trip point across its full operating temperature range without calibration.

How does the TD pin configure the STROBE timeout period on ADM1232ARN?

The TD pin on ADM1232ARN selects the STROBE timeout period by voltage level: 0 V sets 150 ms (min 62.5 ms), floating sets 600 ms (min 250 ms), and VCC sets 1200 ms (min 500 ms). These values are confirmed in Table 1 and Figure 8 of the Rev. C datasheet. The ADM1232ARN uses internal comparators to detect TD state, requiring no external biasing.

Can ADM1232ARN drive a microcontroller reset pin directly without external components?

Yes, ADM1232ARN can drive most microcontroller reset pins directly: the active-high RESET output sources/sinks up to ±10 mA and operates from 4.5 V to 5.5 V, while the open-drain RESET output requires only a single external pull-up resistor (typically 10 kΩ to VCC). No additional capacitors, diodes, or level shifters are needed for standard 5 V MCU interfaces.

What is the maximum allowable VCC rise/fall time for reliable ADM1232ARN operation?

The ADM1232ARN guarantees correct reset assertion for VCC fall times as fast as 10 μs and rise times down to 0 μs (i.e., step-function transitions), per Absolute Maximum Ratings and Figure 9 in the Rev. C datasheet. Its internal bandgap reference and comparator design ensure immunity to typical power supply slew rates encountered in DC-DC converter outputs.

Is ADM1232ARN RoHS compliant and what is its lead finish?

Yes, ADM1232ARN is RoHS compliant (indicated by the "Z" suffix per Ordering Guide), with lead finish of matte tin (Sn) over nickel (Ni) underplate on its R-8 package. This meets JEDEC J-STD-609A Class 1 requirements and supports lead-free reflow soldering profiles up to 260°C peak temperature.