Analog Devices Inc./Maxim Integrated DS1832U+T&R

Overview

DS1832U+T&R from Maxim Integrated (acquired by Analog Devices) is a 3.3-Volt MicroMonitor supervisory IC that monitors VCC, implements a watchdog timer, and manages pushbutton reset for microprocessors. It provides dual active-high/active-low reset outputs (RST/RST), supports 10% or 20% VCC tolerance via TOL pin, delivers ≥250 ms reset pulse width, and operates across –40°C to +85°C - used in embedded industrial controllers requiring reliable power-up/power-down sequencing.

For engineers reviewing the DS1832U+T&R datasheet, DS1832U+T&R pinout, DS1832U+T&R application, or DS1832U+T&R equivalent, key selection criteria include VCC trip point accuracy (2.88 V @ 10%, 2.55 V @ 20%), guaranteed 250 ms reset hold time, non-disableable watchdog with selectable timeout (62.5–2000 ms), push-pull RST output valid down to 0.8 V VCC, and compatibility with 3.0 V and 3.3 V systems.

Technical Context

The DS1832U+T&R integrates three independent supervision functions: precision voltage monitoring using a temperature-compensated bandgap reference and comparator, hardware-debounced pushbutton reset with fixed 250 ms minimum pulse width, and a strobe-controlled watchdog timer with three timeout modes set by TD pin state (GND/floating/VCC). All functions drive dual complementary reset outputs simultaneously.

Its power-monitoring circuit asserts RST/RST when VCC falls below either 2.88 V (TOL = GND) or 2.55 V (TOL = VCC), and holds them active for ≥250 ms after VCC recovery. The watchdog requires periodic ST input strobing; failure triggers identical reset assertion with same timing guarantees.

Key Specifications

Pinout & Package

DS1832U+T&R is supplied in an 8-pin µ-SOP package (118-mil width), pin-compatible with DS1232 and other members of the MicroMonitor family. Package dimensions and thermal characteristics align with JEDEC MO-187AB standards.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326UT29D3+ and TPS3808G33DBVR, DS1832U+T&R uniquely integrates voltage monitoring, pushbutton reset, and watchdog in one 8-pin µ-SOP - reducing component count, eliminating external timing passives, and enabling certified fail-safe behavior without firmware dependencies.

Availability

DS1832U+T&R is available at Aetrix Electronics and suitable for industrial automation, medical device manufacturing, smart metering, and automotive body electronics requiring stable component supply and long-term lifecycle assurance.

Supply support for DS1832U+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 DS1832U+T&R belongs to the MicroMonitor family - engineered specifically for robust microprocessor supervision in harsh environments where deterministic reset behavior, voltage margin flexibility, and hardware-enforced watchdog enforcement are mandatory.

FAQ

What is the function of the TOL pin on the DS1832U+T&R?

The TOL pin selects the VCC detection threshold: when tied to GND, DS1832U+T&R triggers reset at 2.88 V (10% below 3.3 V); when tied to VCC, it triggers at 2.55 V (20% below 3.0 V). This dual-threshold capability allows DS1832U+T&R to serve both 3.3 V and 3.0 V microcontroller platforms without redesign. The selection is static and does not require dynamic switching during operation.

Does the DS1832U+T&R provide both active-high and active-low reset outputs?

Yes, DS1832U+T&R provides two simultaneous, complementary reset outputs: RST (active-high) and RST (active-low). Both outputs are push-pull, share identical timing (≥250 ms pulse width), and remain valid down to 0.8 V VCC. This eliminates the need for external inverters in systems requiring both logic polarities - a key advantage over single-output supervisors like the MAX6326UT29D3+.

Can the watchdog timer on the DS1832U+T&R be disabled?

No, the watchdog timer on DS1832U+T&R cannot be disabled. It is a hardwired, non-software-controllable feature designed for fail-safe operation. To prevent unwanted reset assertion, the ST input must be strobed (H→L transition) before the selected timeout expires - determined by TD pin state. This design enforces continuous firmware health checking, satisfying functional safety requirements in medical and industrial applications.

What is the minimum VCC level at which DS1832U+T&R maintains valid RST output?

DS1832U+T&R maintains valid RST output down to 0.8 V VCC using its internal push-pull driver. Below 0.8 V, a 100 kΩ pull-down resistor from RST to GND extends valid reset assertion to 0 V VCC - critical for controlled shutdown during deep brownout. This behavior is explicitly characterized in the datasheet and distinguishes DS1832U+T&R from supervisors with open-drain outputs requiring external pull-ups.

Is DS1832U+T&R pin-compatible with the DS1232?

Yes, DS1832U+T&R is pin-compatible with the DS1232 in all supported packages (8-pin DIP, SOIC, µ-SOP). Pin assignments, electrical behavior, and functional block diagram match identically - enabling drop-in replacement in legacy designs. However, DS1832U+T&R adds tighter VCC trip point accuracy (±2% vs ±3%) and improved noise immunity (<2 µs pulse rejection), making it a direct upgrade path without PCB modification.