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

Overview

DS1232LPSN/T&R from Maxim Integrated (formerly Dallas Semiconductor) is a low-power microprocessor supervisory IC that monitors VCC supply voltage, implements watchdog timer functionality, and provides pushbutton reset control. It delivers 50 µA quiescent current, supports 5% or 10% VCC trip thresholds (4.5 V or 4.75 V), and asserts active-high and open-drain active-low reset outputs for 250 ms minimum during power-up, power-down, or watchdog timeout - used in embedded industrial controllers requiring reliable brownout and software fault recovery.

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-reset output architecture (RST/RST), selectable watchdog timeout (150/600/1200 ms), TOL-pin-configurable VCC detection accuracy, 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 voltage monitoring with temperature-compensated reference, debounced pushbutton reset with guaranteed 250 ms pulse width, and a non-disableable watchdog timer with TD-pin-selectable timeouts (150 ms, 600 ms, or 1.2 s). Its dual RST outputs support both CMOS-level active-high and open-drain active-low interfacing to diverse microprocessor reset inputs.

Power-fail detection triggers reset when VCC falls below 4.5 V (TOL = VCC) or 4.75 V (TOL = GND); on power-up, reset remains asserted ≥250 ms. The ST input requires periodic high-to-low transitions to prevent timeout, and PBRST accepts active-low pushbutton signals with internal pull-up (40 kΩ typical).

Key Specifications

Pinout & Package

DS1232LPSN/T&R is supplied in an 8-pin SOIC (150-mil) package, pin-compatible with DS1232LPS-2 variant. Package dimensions conform 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 dual-reset outputs, hardware-debounced pushbutton input, and selectable watchdog timeout in a single 8-pin SOIC - eliminating external components needed to replicate its full supervision suite.

Availability

DS1232LPSN/T&R is available at Aetrix Electronics and suitable for industrial automation, medical handheld devices, and factory HMI systems requiring stable component supply, long-term lifecycle support, and guaranteed -40°C to +85°C performance.

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

Maxim Integrated (acquired by Analog Devices in 2021) designs precision analog, mixed-signal, and power management ICs for industrial, automotive, and communications applications.

The DS1232LPSN/T&R belongs to Maxim's MicroMonitor™ family of supervisory circuits, engineered specifically to ensure robust microprocessor startup, runtime integrity, and graceful recovery from power anomalies in harsh operating environments.

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: connecting TOL to ground configures a 10% tolerance (4.75 V trip for 5 V nominal), while connecting it to VCC selects 5% tolerance (4.5 V trip). This allows system designers to match the DS1232LPSN/T&R's power-fail response precisely to their regulator's output specification and noise margin requirements without 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 interface with microcontrollers requiring either reset polarity and supports wired-OR configurations where multiple supervisors share a common reset bus - a capability confirmed in the DS1232LPSN/T&R datasheet pin description and timing diagrams.

Can the watchdog timer on the DS1232LPSN/T&R be disabled?

No, the watchdog timer on the DS1232LPSN/T&R cannot be disabled. As stated in the datasheet note "Watchdog can not be disabled. It must be strobed to avoid resets," the timer is always active once power is applied. To prevent unwanted resets, the ST input must receive a high-to-low transition at intervals shorter than the selected timeout (150/600/1200 ms), making DS1232LPSN/T&R appropriate for systems requiring mandatory runtime supervision.

What is the guaranteed minimum reset pulse width for DS1232LPSN/T&R during power-up?

The DS1232LPSN/T&R guarantees a minimum reset pulse width of 250 ms during power-up, as specified in both the AC Electrical Characteristics table (tRST = 250–1000 ms) and the Operation – Power Monitor section. This duration ensures sufficient time for the +5 V supply and connected microprocessor to stabilize before release from reset - a critical timing parameter verified across temperature and voltage corners in the DS1232LPSN/T&R datasheet.

Is DS1232LPSN/T&R rated for industrial temperature operation?

Yes, DS1232LPSN/T&R is rated for industrial temperature operation from -40°C to +85°C, as explicitly stated in the "Features" list and "Absolute Maximum Ratings" section of the datasheet. The "N" suffix in the part number denotes the industrial-grade version, and all electrical specifications in the DC and AC tables are validated across this full range - confirming suitability for deployment in factory floors, outdoor equipment, and other thermally demanding environments.