Analog Devices Inc./Maxim Integrated DS1232LPSN-2+

Overview

DS1232LPSN-2+ from Maxim Integrated (formerly Dallas Semiconductor) is a low-power microprocessor supervisory circuit that monitors VCC, implements watchdog timer functionality, and provides pushbutton reset control. It delivers 50 µA quiescent current, supports 5% or 10% VCC threshold detection (4.5 V or 4.75 V trip points), and guarantees ≥250 ms active reset pulse width. Used in embedded industrial controllers requiring reliable power-up sequencing and software fault recovery.

For engineers reviewing the DS1232LPSN-2+ datasheet, DS1232LPSN-2+ pinout, DS1232LPSN-2+ application, or DS1232LPSN-2+ equivalent, key selection criteria include VCC detection accuracy, watchdog timeout configurability (150 ms / 600 ms / 1.2 s), dual RST outputs (active-high and open-drain active-low), industrial temperature range (–40°C to +85°C), and SOIC-8 package compatibility with legacy DS1232 designs.

Technical Context

The DS1232LPSN-2+ integrates three independent monitoring functions: precision VCC comparator with TOL-selectable trip point (4.25–4.74 V), debounced pushbutton reset input (PBRST) generating ≥250 ms reset pulses, and programmable watchdog timer with TD-configurable timeouts (150 ms/600 ms/1.2 s). All functions operate over full industrial temperature range.

It features dual reset outputs - RST (active-high CMOS) and RST̅ (active-low open-drain) - enabling direct interface with both TTL and microcontroller reset inputs requiring pull-up or level-shifting. The device draws only 50 µA typical supply current in quiescent state and maintains reset assertion for ≥250 ms after power-up or power-fail recovery.

Key Specifications

Pinout & Package

DS1232LPSN-2+ is housed in an 8-pin SOIC package (150-mil body width), pin-compatible with industry-standard DS1232 variants and suitable for automated PCB assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326US29D3+ and TPS3808G125DBVR, DS1232LPSN-2+ uniquely combines VCC monitoring, pushbutton reset, and programmable watchdog in one SOIC-8 package - eliminating need for discrete timing components or secondary supervision ICs in resource-constrained embedded designs.

Availability

DS1232LPSN-2+ is available at Aetrix Electronics and suitable for industrial automation, medical diagnostics, smart metering, and automotive telematics applications requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.

Supply support for DS1232LPSN-2+ 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 (acquired by Analog Devices in 2021) designs precision analog, mixed-signal, and power management ICs for industrial, communications, and computing markets.

The DS1232LPSN-2+ belongs to Maxim's MicroMonitor™ family of supervisory circuits, engineered specifically for robust microprocessor system reliability in harsh environments with variable power and thermal conditions.

FAQ

What is the function of the TOL pin on the DS1232LPSN-2+?

The TOL pin on the DS1232LPSN-2+ selects the VCC detection threshold: connecting TOL to GND sets a 5% tolerance trip point (4.50–4.74 V), while connecting it to VCC selects a 10% tolerance (4.25–4.49 V). This allows field-configurable supply monitoring without changing the DS1232LPSN-2+ component or PCB layout, supporting design reuse across different power rail specifications.

Does the DS1232LPSN-2+ provide both active-high and active-low reset outputs?

Yes, the DS1232LPSN-2+ provides two independent reset outputs: RST (active-high CMOS) and RST̅ (active-low open-drain). This dual-output architecture enables direct connection to microcontrollers requiring either logic-high or logic-low reset assertion, and the open-drain RST̅ supports level shifting and wired-OR configurations in multi-voltage systems.

How is the watchdog timeout configured on the DS1232LPSN-2+?

The watchdog timeout on the DS1232LPSN-2+ is set using the TD pin: grounding TD yields ~150 ms timeout, leaving TD unconnected yields ~600 ms, and tying TD to VCC yields ~1.2 s. The watchdog cannot be disabled and must be strobed via the ST pin at intervals shorter than the selected timeout to prevent unintended reset assertion.

What is the guaranteed minimum reset pulse width for the DS1232LPSN-2+?

The DS1232LPSN-2+ guarantees a minimum reset pulse width of 250 ms for both RST and RST̅ outputs, whether triggered by power-up, power-fail recovery, or pushbutton release. This duration ensures adequate stabilization time for microprocessors, memory, and peripheral ICs before normal execution resumes.

Is the DS1232LPSN-2+ qualified for industrial temperature operation?

Yes, the DS1232LPSN-2+ is rated for industrial temperature operation from –40°C to +85°C, as indicated by the "N" suffix in its part number. This qualification ensures reliable performance in demanding environments such as factory automation, outdoor metering, and transportation infrastructure where ambient thermal extremes are common.