Analog Devices Inc./Maxim Integrated DS1232S

Overview

DS1232S from Maxim Integrated (formerly Dallas Semiconductor) is a microprocessor supervisory circuit in 16-pin SOIC package that monitors VCC, implements pushbutton reset with 250 ms debounced output, and provides watchdog timer with selectable timeouts (150 ms/600 ms/1.2 s). It delivers active-high and open-drain active-low reset outputs, supports 5% or 10% VCC tolerance via TOL pin, and operates across -40°C to +85°C for industrial applications.

For engineers reviewing the DS1232S datasheet, DS1232S pinout, DS1232S application, or DS1232S equivalent, key selection considerations include dual-reset output polarity, programmable watchdog timeout via TD pin, VCC trip point selection (4.25 V or 4.50 V), and industrial temperature rating - all critical for reliable embedded system power-up, brownout, and software fault recovery.

Technical Context

The DS1232S integrates three independent monitoring functions: precision voltage detection using a temperature-compensated bandgap reference and comparator, hardware-debounced pushbutton reset with guaranteed 250 ms minimum pulse width, and a non-disableable watchdog timer whose timeout is set by TD pin state (GND/float/VCC). All functions drive both RST (active-high) and RST (open-drain active-low) outputs simultaneously.

Power-on reset asserts both reset outputs for ≥250 ms; power-fail detection triggers reset when VCC falls below 4.25 V (TOL=VCC) or 4.50 V (TOL=GND); watchdog timeout occurs if ST input is not strobed low within the selected interval, forcing reset for ≥250 ms. No external components are required for basic operation.

Key Specifications

Pinout & Package

DS1232S is housed in a 16-pin SOIC (300-mil) surface-mount package with 0.3-inch body width and standard JEDEC MS-013AC footprint. Pin 1 is top-left corner, pin 16 top-right, pins numbered counter-clockwise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX692AESA+ and TPS3823-50DBVR, the DS1232S uniquely combines dual-polarity reset, selectable VCC trip point, and programmable watchdog timeout in a single 16-pin SOIC - enabling full supervision capability without external components or firmware overhead.

Availability

DS1232S is available at Aetrix Electronics and suitable for industrial PLC control, medical diagnostic equipment, telecom line cards, and automotive infotainment head units requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.

Supply support for DS1232S 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

Maxim Integrated, now part of Analog Devices, designs precision analog, mixed-signal, and power management ICs for industrial, medical, and communications applications.

The DS1232S belongs to the MicroMonitor™ family of supervisory circuits engineered specifically for robust microprocessor reset and watchdog management in harsh, real-world embedded systems.

FAQ

What is the function of the TOL pin on the DS1232S?

The TOL pin on the DS1232S selects the VCC detection threshold: grounded for 5% tolerance (trip at 4.50 V) or tied to VCC for 10% tolerance (trip at 4.25 V). This allows system designers to match the DS1232S trip point precisely to their 5 V rail's specification without external components. The DS1232S uses this setting to determine when to assert RST and RST during brownout conditions.

Does the DS1232S provide both active-high and active-low reset outputs?

Yes, the DS1232S provides two independent reset outputs: RST is an active-high push-pull output, and the second RST is an active-low open-drain output. This dual-output architecture allows direct interfacing with MCUs requiring either polarity without external inverters or pull-up resistors. Both outputs are asserted simultaneously during power-up, brownout, pushbutton event, or watchdog timeout in the DS1232S.

How is the watchdog timeout configured on the DS1232S?

The watchdog timeout on the DS1232S is set exclusively by the TD pin: connect TD to GND for ~150 ms, leave TD floating for ~600 ms, or tie TD to VCC for ~1.2 s. The DS1232S does not support disabling the watchdog - it must be strobed via the ST pin at least once per timeout interval to prevent reset assertion. This configuration requires no external timing components.

What is the minimum reset pulse width guaranteed by the DS1232S?

The DS1232S guarantees a minimum reset pulse width of 250 ms for all reset sources: power-on, power-fail, pushbutton release, and watchdog timeout. This duration is internally generated and independent of external capacitance or supply slew rate. The DS1232S maintains both RST and RST in the active state for ≥250 ms to ensure complete microprocessor initialization and clock stabilization before release.

Is the DS1232S rated for industrial temperature operation?

Yes, the DS1232S is specified for operation from -40°C to +85°C, meeting industrial temperature requirements. This rating is confirmed in the Absolute Maximum Ratings table and applies to the full range of electrical and timing specifications. The DS1232S achieves this performance using temperature-compensated internal references and robust process design - no derating or external compensation is needed across the full range.