Analog Devices Inc./Maxim Integrated DS1232LPS+T&R

Overview

DS1232LPS+T&R from Maxim Integrated (formerly Dallas Semiconductor) is a low-power microprocessor supervisory IC that monitors VCC, implements pushbutton reset with 250 ms debounce, and provides watchdog timer timeout options of 150 ms/600 ms/1.2 s. It delivers active-high and open-drain active-low reset outputs, supports 5% or 10% VCC threshold selection via TOL pin, and operates across -40°C to +85°C in industrial environments.

For engineers reviewing the DS1232LPS+T&R datasheet, DS1232LPS+T&R pinout, DS1232LPS+T&R application, or DS1232LPS+T&R equivalent, key selection considerations include dual-reset output polarity, programmable watchdog timeout via TD pin, selectable VCC trip point (4.5 V or 4.75 V), and compatibility with 8-pin SOIC (150-mil) and 16-pin SOIC packages.

Technical Context

The DS1232LPS+T&R integrates three independent monitoring functions: precision VCC 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).

Its dual RST outputs - one CMOS active-high, one open-drain active-low - enable direct interfacing with both TTL and microcontroller reset inputs requiring pull-up or level-shifting. The TOL pin selects between 4.75 V (5% tolerance at 5 V) and 4.50 V (10% tolerance) trip points, while ST input strobing resets the watchdog before timeout.

Key Specifications

Pinout & Package

DS1232LPS+T&R is supplied in an 8-pin SOIC package (150-mil width), with pinout identical to DS1232LPS-2 variant per mechanical drawings.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326US29D3+ and TPS3808G33DBVR, the DS1232LPS+T&R uniquely combines dual-polarity reset outputs, hardware pushbutton debounce, and programmable watchdog timeout in a single 8-pin SOIC - eliminating discrete support components and reducing BOM count in resource-constrained designs.

Availability

DS1232LPS+T&R is available at Aetrix Electronics and suitable for industrial PLC control, medical diagnostic equipment, automotive body control modules, and smart energy metering requiring stable component supply and long-term lifecycle support.

Supply support for DS1232LPS+T&R 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, automotive, and computing applications.

The DS1232LPS+T&R belongs to Maxim's MicroMonitor™ supervisory IC family, engineered specifically for robust microprocessor reset and watchdog functionality in mission-critical embedded systems.

FAQ

What is the function of the TOL pin on the DS1232LPS+T&R?

The TOL pin on the DS1232LPS+T&R selects the VCC trip point: connecting TOL to GND sets a 4.75 V threshold (5% tolerance at 5 V), while connecting it to VCC sets a 4.50 V threshold (10% tolerance). This allows system designers to match the DS1232LPS+T&R's power-fail detection to their specific supply rail stability requirements without external components.

Does the DS1232LPS+T&R support both active-high and active-low reset outputs simultaneously?

Yes, the DS1232LPS+T&R provides two independent reset outputs: RST is a CMOS active-high output, and RST̅ is an open-drain active-low output. Both assert simultaneously during power-up, power-down, watchdog timeout, or pushbutton event. This dual-output architecture enables direct interface with diverse microcontrollers - including those requiring pulled-up reset lines or inverted logic levels - without additional buffering.

How is the watchdog timeout configured on the DS1232LPS+T&R?

The watchdog timeout on the DS1232LPS+T&R is set by the voltage applied to the TD pin: GND yields ~150 ms, floating yields ~600 ms, and VCC yields ~1.2 s. The watchdog cannot be disabled; it must be strobed via the ST pin at least once per timeout interval to prevent reset assertion. This ensures continuous software health monitoring in safety-aware applications.

What package type is used for the DS1232LPS+T&R?

The DS1232LPS+T&R is supplied in an 8-pin SOIC package with 150-mil body width (also designated DS1232LPS-2 in datasheet mechanical drawings). This surface-mount package supports automated assembly and offers thermal and mechanical reliability suitable for industrial PCB layouts.

Is the DS1232LPS+T&R compatible with 3.3 V microcontrollers?

No - the DS1232LPS+T&R is specified for 5 V operation only (VCC = 4.5 V to 5.5 V) and its internal reference and comparators are calibrated for 5 V systems. While its RST̅ output can interface with 3.3 V logic via appropriate pull-up voltage, the device itself must be powered from a 5 V rail and does not support direct 3.3 V supply or threshold adjustment for lower voltages.