Analog Devices Inc./Maxim Integrated DS1831S+

Overview

DS1831S+ from Maxim Integrated is a multisupply voltage monitor and reset IC designed for systems with dual 5V/3.3V power rails. It provides independent open-drain reset outputs for both supplies (RST5V, RST3.3V), user-configurable trip tolerances (5%/10%/15% for 5V; 5%/10%/20% for 3.3V), and selectable reset time delays (10ms/100ms/1s). It operates from −40°C to +85°C and draws internal power from the higher of IN5V or IN3.3V - enabling robust monitoring in mixed-supply embedded controllers and industrial PLCs.

For engineers reviewing the DS1831S+ datasheet, DS1831S+ pinout, DS1831S+ application, or DS1831S+ equivalent, this device supports critical power sequencing, manual pushbutton override (PBRST5V/PBRST3.3V), non-maskable interrupt generation (NMI1/NMI2) for upstream voltage supervision, and tolerance/time-delay configuration via dedicated TOL/TD pins - all in a compact 16-pin SOIC (150mil) package.

Technical Context

The DS1831S+ integrates two precision voltage comparators referenced to a 1.25V temperature-compensated bandgap, enabling accurate monitoring of 5V and 3.3V supplies with programmable trip points (e.g., 4.63V typ. at 5% tolerance for IN5V; 3.06V typ. at 5% for IN3.3V). Its internal bias circuitry ensures valid operation as long as either supply exceeds 1.0V, with full accuracy requiring ≥1.5V on at least one supply input.

Reset timing is controlled by external TD5V/TD3.3V logic levels (GND/float/VCC), selecting guaranteed minimum active durations of 10ms, 100ms, or 1000ms. The device features internal 100kΩ pull-ups on all pushbutton inputs (PBRST5V, PBRST3.3V, MPBRST), debounced logic, and open-drain outputs requiring external pull-ups - supporting wired-OR reset distribution without level-shifting.

Key Specifications

Pinout & Package

DS1831S+ is housed in a 16-pin SOIC (150mil) package with 1.27mm pitch, JEDEC MS-012AC compliant, and RoHS-compliant lead finish.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multisupply monitoring applications.

Compared with MAX6369ESA+ and TPS3808G33DBVR, the DS1831S+ uniquely integrates dual-rail tolerance programming, two NMI-capable sense inputs, and three pushbutton interfaces in one 16-pin SOIC - delivering system-level supervision without external logic or multiple ICs.

Availability

DS1831S+ is available at Aetrix Electronics and suitable for industrial automation, telecom infrastructure, and medical electronics requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for DS1831S+ 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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management solutions for industrial, communications, and computing markets.

The DS1831S+ belongs to Maxim's Micromonitor™ family of power-supervisory ICs, engineered for systems requiring precise, configurable, and fault-resilient power-up sequencing and brownout protection in space-constrained designs.

FAQ

What is the minimum supply voltage required for DS1831S+ to function?

The DS1831S+ requires at least one of its supply inputs (IN5V or IN3.3V) to be ≥1.0V to maintain basic output validity. For accurate voltage monitoring - including correct trip-point detection and comparator operation - at least one supply must reach ≥1.5V. Below 1.5V, the device holds all outputs active but cannot reliably detect out-of-tolerance conditions on monitored rails.

How does DS1831S+ handle power sequencing when both IN5V and IN3.3V ramp at different rates?

The DS1831S+ draws internal power from the higher of IN5V or IN3.3V, ensuring continuous operation even during asymmetric ramp-up. Each reset output (RST5V, RST3.3V) is independently enabled only after its respective supply reaches the configured tolerance window - preventing premature release of reset signals. This allows safe, rail-specific sequencing without external timing components.

Can DS1831S+ monitor voltages other than 5V and 3.3V?

Yes. DS1831S+ includes two dedicated sense inputs (IN1 and IN2), each compared against an internal 1.25V reference with 100µV hysteresis. By using external resistor dividers, users can scale higher voltages (e.g., 12V, 24V) down to the 1.25V threshold - enabling NMI1/NMI2 interrupts for auxiliary rail faults without adding discrete comparators.

What happens if both TOL5V and TOL3.3V pins are left floating?

If TOL5V is left floating, the DS1831S+ configures the 5V trip point to 4.15V typical (15% tolerance). If TOL3.3V is left floating, the 3.3V trip point becomes 2.55V typical (20% tolerance). These configurations are latched at power-up and remain fixed until the next power cycle - providing predictable, no-component tolerance settings for rapid prototyping.

Is DS1831S+ pin-compatible with other variants in the DS1831 family?

Yes. DS1831S+, DS1831S, DS1831AS, DS1831BS, and DS1831A share identical 16-pin SOIC (150mil) pinouts and footprint. Functional differences (e.g., watchdog in DS1831AS, pushbutton status in DS1831BS) map to unused pins in DS1831S+ - enabling drop-in replacement in designs not utilizing those features.