Analog Devices Inc./Maxim Integrated DS1831

Overview

DS1831 from Maxim Integrated is a multisupply micromonitor IC that monitors 5V and 3.3V power rails plus two user-configurable voltage inputs (IN1, IN2), provides dual open-drain reset outputs (RST5V, RST3.3V), two non-maskable interrupt outputs (NMI1, NMI2), and master pushbutton reset (MPBRST). It draws internal power from the higher of IN5V or IN3.3V, operates from −40°C to +85°C, and supports 5%/10%/15% tolerance selection on 5V and 5%/10%/20% on 3.3V. Used in embedded systems requiring robust multi-rail power supervision with manual override and fault signaling.

For engineers reviewing the DS1831 datasheet, DS1831 pinout, DS1831 application, or DS1831 equivalent, this page delivers verified specifications including trip point tolerances, reset time delays (10ms/100ms/1s), NMI pulse width (≥10µs), comparator reference (1.25V ±100mV), and dual-supply operation - all confirmed for the DS1831 variant (not DS1831A or DS1831B).

Technical Context

The DS1831 integrates two independent voltage comparators referenced to a precision 1.25V temperature-compensated bandgap, each driving an open-drain NMI output with 100µV hysteresis and ≥2µs noise immunity. Its reset logic asserts RST5V and RST3.3V low when respective supply voltages fall outside user-selected tolerance windows (set via TOL5V/TOL3.3V pins), holding active for configurable delays (10ms/100ms/1s) after recovery, as determined by TD5V/TD3.3V states.

Internal power routing selects the higher voltage between IN5V and IN3.3V (≥1.0V required for operation; ≥1.5V needed for accurate monitoring), eliminating external biasing. The MPBRST input forces both resets and NMIs active when pulled low, debounced internally with a 100kΩ pull-up to the dominant supply rail - enabling system-level manual reset coordination without external components.

Key Specifications

Pinout & Package

DS1831 is available in 16-pin 300mil DIP and 16-pin 150mil SO packages. Both share identical pin mapping and functionality.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6369 and TPS3808G33, the DS1831 uniquely integrates dual-rail supervision, two auxiliary comparators with NMI outputs, master pushbutton coordination, and field-selectable tolerances/timing - making it irreplaceable in systems requiring comprehensive, configurable power integrity management across multiple voltage domains.

Availability

DS1831 is available at Aetrix Electronics and suitable for industrial automation, telecom infrastructure, medical diagnostics, and automotive infotainment applications requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for DS1831 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 power management, sensing, and interface applications in industrial, automotive, and communications markets.

The DS1831 belongs to Maxim's Micromonitor® family of power-supervisory ICs, engineered specifically for systems with multiple voltage rails needing coordinated reset, fault signaling, and manual override - not just basic reset generation.

FAQ

What is the minimum supply voltage required for DS1831 to operate?

The DS1831 requires at least one of its supply inputs (IN5V or IN3.3V) to be ≥1.0V to maintain basic output functionality. However, accurate voltage monitoring - including correct trip point evaluation and NMI generation - requires at least one supply to reach ≥1.5V. Below 1.5V, all outputs remain asserted active low. This behavior is documented in the "OUTPUT VALID CONDITIONS" section of the DS1831 datasheet.

How does the DS1831 select its internal power source?

The DS1831 automatically selects the higher voltage between IN5V and IN3.3V to power its internal circuitry. If IN5V = 5.0V and IN3.3V = 3.3V, the device draws current from IN5V; if IN3.3V rises to 4.0V while IN5V remains at 3.0V, internal bias switches to IN3.3V. This dual-supply autonomy eliminates the need for external regulators or diode-OR circuits in the DS1831 power path.

Can the DS1831 monitor voltages other than 5V and 3.3V?

Yes - the DS1831 includes two dedicated sense inputs (IN1 and IN2) referenced to its internal 1.25V precision bandgap. By using external resistor dividers, users can scale higher voltages (e.g., 12V, 24V) down to 1.25V for comparison. The DS1831 then generates NMI pulses when those scaled inputs fall below threshold, enabling supervision of arbitrary rails without additional components.

What happens when the MPBRST pin is pulled low on the DS1831?

Pulling MPBRST low for ≥20µs forces both RST5V and RST3.3V outputs, as well as NMI1 and NMI2, into active-low states for the full duration of their configured reset time delays (10ms/100ms/1s). This coordinated assertion occurs regardless of current supply status and is debounced internally via a 100kΩ pull-up to the dominant supply rail - ensuring robust manual reset even under noisy conditions.

How are tolerance and time-delay settings applied on the DS1831?

Tolerance (TOL5V/TOL3.3V) and time-delay (TD5V/TD3.3V) configurations are latched at power-up and remain fixed until the next power cycle. TOL pins set trip point accuracy (e.g., TOL5V=VCC → 4.50–4.75V), while TD pins determine reset hold duration (e.g., TD5V=GND → 10ms). These settings cannot be changed dynamically during operation - design intent is hardware-configurable, not software-programmable.