Analog Devices Inc./Maxim Integrated DS1232SN/T&R

Overview

DS1232SN/T&R from Maxim Integrated (formerly Dallas Semiconductor) is a microprocessor supervisory circuit that monitors VCC, implements pushbutton reset with 250 ms debounce, and provides a configurable watchdog timer with timeout options of ~150 ms, ~600 ms, or ~1.2 s. It delivers dual active-high and open-drain active-low reset outputs and operates over -40°C to +85°C in industrial applications such as embedded controllers and power-sensitive instrumentation.

For engineers reviewing the DS1232SN/T&R datasheet, DS1232SN/T&R pinout, DS1232SN/T&R application, or DS1232SN/T&R equivalent, key selection considerations include VCC trip point selection (4.5 V or 4.75 V), guaranteed 250 ms minimum reset pulse width, watchdog timeout configuration via TD pin, dual RST output types, and industrial temperature rating.

Technical Context

The DS1232SN/T&R integrates three independent monitoring functions: precision VCC detection using a temperature-compensated reference and comparator, debounced pushbutton reset with fixed 250 ms active pulse, and a non-disableable watchdog timer whose timeout is set by TD pin state (GND/float/VCC). All functions drive two synchronized reset signals: RST (active-high) and RST (open-drain active-low).

Power-up reset is held for ≥250 ms; power-down reset asserts when VCC falls below threshold (4.25–4.49 V or 4.50–4.74 V depending on TOL pin); watchdog timeout triggers reset if ST input is not strobed within selected interval. No external components are required for basic operation.

Key Specifications

Pinout & Package

DS1232SN/T&R is supplied in an 8-pin mini-DIP package (300-mil width), with pin 1 at top-left corner when notch faces up. Pin assignments are validated per Maxim's official DS1232/DS1232S datasheet Rev. 0.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX692AESA+ and TPS3823-50DBVR, DS1232SN/T&R uniquely combines dual-polarity reset outputs, user-selectable VCC trip point, hardware-debounced pushbutton input, and configurable watchdog-all in one 8-pin DIP-making it optimal for robust, feature-complete microprocessor supervision where layout space and functional integration are critical.

Availability

DS1232SN/T&R is available at Aetrix Electronics and suitable for industrial automation, medical instrumentation, automotive body electronics, and smart metering applications requiring stable component supply across extended product lifecycles.

Supply support for DS1232SN/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, communications, and computing markets.

The DS1232SN/T&R belongs to Maxim's MicroMonitor™ family of supervisory circuits, engineered specifically to replace discrete reset generators and watchdog timers in microprocessor-based systems demanding reliability, simplicity, and industrial-grade operation.

FAQ

What is the function of the TOL pin on the DS1232SN/T&R?

The TOL pin on the DS1232SN/T&R selects the VCC trip voltage threshold: when tied to GND, the device triggers reset when VCC falls below 4.50–4.74 V; when tied to VCC, reset activates below 4.25–4.49 V. This allows system designers to match the DS1232SN/T&R's brown-out detection precisely to their microprocessor's minimum operating voltage specification without external components.

Does the DS1232SN/T&R provide both active-high and active-low reset outputs?

Yes, the DS1232SN/T&R provides two synchronized reset outputs: RST (pin 5) is an active-high push-pull output, and RST (pin 6) is an active-low open-drain output. This dual-output architecture enables direct compatibility with microcontrollers requiring either reset polarity-and the open-drain RST allows wired-OR configurations or level translation via external pull-up resistors.

How is the watchdog timeout configured on the DS1232SN/T&R?

The watchdog timeout on the DS1232SN/T&R is set by the TD pin (pin 2): connecting TD to GND selects ~150 ms, leaving TD floating selects ~600 ms, and connecting TD to VCC selects ~1.2 s. The watchdog cannot be disabled-it must be strobed via the ST input at intervals shorter than the selected timeout to prevent reset assertion. This ensures fail-safe operation in the DS1232SN/T&R.

What is the minimum reset pulse width guaranteed by the DS1232SN/T&R?

The DS1232SN/T&R guarantees a minimum reset pulse width of 250 ms for both RST and RST outputs-whether triggered by power-up, power-down, or pushbutton reset. This duration is internally timed and independent of external capacitors or supply slew rate, ensuring reliable processor initialization across varying board-level power delivery characteristics.

Is the DS1232SN/T&R suitable for industrial temperature applications?

Yes, the DS1232SN/T&R is rated for operation from -40°C to +85°C, meeting industrial temperature requirements. The "N" suffix in DS1232SN/T&R explicitly denotes the industrial-grade version, qualified across this full range with tested performance for VCC trip points, reset timing, and watchdog accuracy-making it appropriate for deployment in factory automation, outdoor metering, and transportation electronics.