Analog Devices Inc./Maxim Integrated DS1831DS+

Overview

DS1831DS+ from Maxim Integrated is a 2.5V/3.3V multisupply micro-monitor IC with integrated watchdog timer, dual open-drain reset outputs (RST2.5V and RST3.3V), precision 1.25V bandgap reference, and two user-configurable voltage sense inputs (IN1, IN2). It monitors power integrity during startup, brownout, and transient events in mixed-voltage embedded systems. Key parameters include ±5%/±10%/±15% selectable 2.5V tolerance, ±5%/±10%/±20% selectable 3.3V tolerance, 10ms/100ms/1s programmable reset delays, -40°C to +85°C operating range, and 16-pin SOIC (150mil) package.

For engineers reviewing the DS1831DS+ datasheet, DS1831DS+ pinout, DS1831DS+ application, or DS1831DS+ equivalent, this page delivers verified functional identity, confirmed watchdog-enabled variant status, validated pin mapping for SOIC-16, exact trip point tolerances per TOL input state, and real-world selection guidance against comparable multisupply supervisors with watchdog capability.

Technical Context

The DS1831DS+ implements independent voltage monitoring for 2.5V and 3.3V supplies using internal 1.25V bandgap-referenced comparators, with tolerance selection via TOL2.5V/TOL3.3V pins and time-delay configuration via TD2.5V/TD3.3V pins. Its watchdog function activates on ST input edge absence, timed by TDWD pin state (10ms/100ms/1s), and asserts WDS output to trigger system reset.

Internal power derives from the higher of IN2.5V or IN3.3V (≥1.0V required), enabling operation during asymmetric supply sequencing. All RST and NMI outputs are open-drain, requiring external pull-ups; the device maintains valid outputs as long as ≥1 input remains >1.0V and accurate monitoring requires ≥1 supply >1.5V.

Key Specifications

Pinout & Package

DS1831DS+ uses a 16-pin SOIC (150mil) package with 1.27mm pitch, JEDEC MS-012AC compliant, suitable for automated assembly and high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multisupply supervisor with watchdog applications.

Compared with MAX6816ESE+ and TPS3808G33DBVR, DS1831DS+ uniquely integrates dual-rail (2.5V/3.3V) monitoring, independent reset outputs with per-rail tolerance/delay programming, and watchdog functionality in one SOIC-16 package-enabling coordinated power sequencing and fault recovery unattainable with single-rail alternatives.

Availability

DS1831DS+ is available at Aetrix Electronics and suitable for industrial automation, telecom infrastructure, medical imaging, and automotive ADAS applications requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for DS1831DS+ 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 (now part of Analog Devices) designs precision analog and mixed-signal ICs for industrial, communications, and computing markets, emphasizing reliability, integration, and thermal robustness.

The DS1831DS+ belongs to the MicroMonitor™ family of multisupply supervisors, engineered specifically for complex embedded systems requiring coordinated reset sequencing, watchdog safety monitoring, and auxiliary voltage fault detection across multiple power domains.

FAQ

What is the key functional distinction between DS1831DS+ and DS1831CS?

The DS1831DS+ integrates a watchdog timer with ST input and WDS output, while DS1831CS does not. DS1831DS+ replaces the NMI2 and MPBRST pins of DS1831CS with WDS and TDWD, enabling software hang detection. Both share identical 2.5V/3.3V monitoring, dual reset outputs, and SOIC-150mil packaging. DS1831DS+ is the correct choice when system-level watchdog supervision is required alongside power monitoring.

How does DS1831DS+ determine its internal power source?

DS1831DS+ draws internal operating current exclusively from the higher of the IN2.5V or IN3.3V supply inputs. At least one of these inputs must exceed 1.0V for basic operation, and accurate voltage monitoring requires at least one supply to be above 1.5V. This self-powering architecture eliminates dependency on an external VCC rail and supports asymmetric power-up sequencing common in FPGA and ASIC platforms.

Can DS1831DS+ monitor voltages other than 2.5V and 3.3V?

Yes. DS1831DS+ includes IN1 and NMI1 pins that form a 1.25V-referenced comparator. By using an external resistor divider on IN1, users can scale higher voltages (e.g., 5V, 12V, 24V) down to the 1.25V threshold for fault detection. The DS1831DS+ datasheet provides design equations and example circuits for configuring trip points such as 11.5V using standard resistor values.

What are the valid logic states for TD2.5V, TD3.3V, and TDWD on DS1831DS+?

Each TD pin (TD2.5V, TD3.3V, TDWD) accepts three valid states: grounded (GND), floating (open), or connected to the higher supply rail (VCC, i.e., greater of IN2.5V or IN3.3V). These states select 10ms, 100ms, or 1000ms timing respectively. No pull-up or pull-down resistors are needed beyond the internal structure; direct connection or open-circuit suffices for configuration.

Is DS1831DS+ pin-compatible with DS1831D in the same SOIC-150mil package?

Yes. DS1831DS+ and DS1831D share identical pinouts, electrical specifications, and SOIC-150mil packaging. DS1831DS+ is the surface-mount variant of the DS1831D DIP version; both implement the same watchdog-enabled multisupply monitoring functionality. Board designs using DS1831D can migrate to DS1831DS+ without layout changes, provided solder profile and thermal constraints for SOIC are met.