Analog Devices Inc./Maxim Integrated DS1232LPSN+T&R

Overview

DS1232LPSN+T&R from Maxim Integrated (acquired by Analog Devices) is a low-power microprocessor supervisory IC that monitors VCC supply voltage, provides pushbutton reset control, and implements a programmable watchdog timer. It delivers 50 µA quiescent current, supports 5% or 10% VCC trip thresholds (4.50–4.74 V or 4.25–4.49 V), and guarantees ≥250 ms active reset pulse width. Used in embedded controllers where reliable power-up sequencing and software fault recovery are critical.

For engineers reviewing the DS1232LPSN+T&R datasheet, DS1232LPSN+T&R pinout, DS1232LPSN+T&R application, or DS1232LPSN+T&R equivalent, key selection considerations include its dual RST/RST outputs (active-high and open-drain active-low), TOL-selectable voltage tolerance, TD-programmable watchdog timeout (150/600/1200 ms), and industrial-grade -40°C to +85°C operation in 8-pin SOIC package.

Technical Context

The DS1232LPSN+T&R integrates three independent monitoring functions: precision VCC comparator with temperature-compensated reference, debounced pushbutton reset input (PBRST), and edge-triggered watchdog timer controlled via ST strobe and TD configuration. Its dual-reset outputs enable direct interface to both CMOS and TTL processors without external level-shifting.

Power-fail detection initiates reset when VCC drops below the TOL-selected threshold (4.5 V or 4.25 V nominal), and reset remains asserted for ≥250 ms after VCC recovery. The watchdog timer requires periodic high-to-low transitions on ST - failure to strobe within the TD-set timeout (e.g., 600 ms typical when TD is floating) forces reset assertion for ≥250 ms.

Key Specifications

Pinout & Package

DS1232LPSN+T&R is packaged in an 8-pin SOIC (150-mil width), pin-compatible with DS1232LPS-2 variant. Package outline conforms to JEDEC MS-012AA.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326US29D3+ and TPS3808G33DBVR, DS1232LPSN+T&R uniquely integrates VCC monitoring, pushbutton reset, and programmable watchdog in one 8-pin SOIC - eliminating board space, BOM count, and timing coordination overhead for compact embedded designs.

Availability

DS1232LPSN+T&R is available at Aetrix Electronics and suitable for industrial control systems, medical diagnostics equipment, point-of-sale terminals, and smart energy meters requiring stable component supply and long-term lifecycle support.

Supply support for DS1232LPSN+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

Analog Devices (via acquisition of Maxim Integrated) designs high-reliability analog and mixed-signal ICs for precision sensing, power management, and system supervision.

The DS1232LPSN+T&R belongs to Maxim's MicroMonitor™ family - engineered specifically for robust microprocessor supervision in harsh industrial and medical environments where deterministic reset behavior and low-power reliability are non-negotiable.

FAQ

What is the function of the TOL pin on the DS1232LPSN+T&R?

The TOL pin on the DS1232LPSN+T&R selects the VCC detection threshold tolerance: connecting TOL to GND sets a 5% trip point (4.50–4.74 V), while connecting it to VCC selects a 10% trip point (4.25–4.49 V). This allows system designers to adapt DS1232LPSN+T&R to different power rail stability requirements without changing the IC or adding external components.

Does the DS1232LPSN+T&R provide both active-high and active-low reset outputs?

Yes, the DS1232LPSN+T&R provides two independent reset outputs: RST is an active-high push-pull output, and RST is an active-low open-drain output. This dual-output architecture enables direct interfacing with diverse microcontrollers - including those requiring active-low reset with external pull-up or active-high CMOS-compatible signals - without additional logic or level-shifting circuitry.

How is the watchdog timeout configured on the DS1232LPSN+T&R?

The watchdog timeout on the DS1232LPSN+T&R is set via the TD pin: grounding TD yields ~150 ms, leaving TD floating yields ~600 ms, and connecting TD to VCC yields ~1.2 s. The watchdog timer resets on each high-to-low transition at the ST pin; failure to strobe within the selected timeout forces DS1232LPSN+T&R to assert both RST outputs for ≥250 ms.

What is the operating temperature range specified for the DS1232LPSN+T&R?

The DS1232LPSN+T&R is rated for industrial operation from -40°C to +85°C, as indicated by the "N" suffix in the part number. This extended temperature range ensures reliable performance in uncontrolled environments such as factory floors, outdoor utility meters, and portable medical devices - without requiring thermal derating or supplemental cooling.

Can the DS1232LPSN+T&R be used with a 3.3 V microprocessor system?

No - the DS1232LPSN+T&R is designed exclusively for 5 V systems, with a supply range of 4.5 V to 5.5 V and VCC trip thresholds centered at 4.5 V or 4.25 V. Its RST outputs are not 3.3 V tolerant, and its internal reference is calibrated for 5 V operation. For 3.3 V supervision, a dedicated 3.3 V supervisor like the MAX6326 or TPS3808 series should be used instead of DS1232LPSN+T&R.