Analog Devices Inc./Maxim Integrated DS1831+

Overview

DS1831+ from Maxim Integrated is a multisupply voltage monitor IC that detects out-of-tolerance conditions on 5V and 3.3V power rails while providing two additional user-configurable voltage sense inputs (IN1, IN2), dual open-drain reset outputs (RST5V, RST3.3V), and pushbutton-controlled reset sequencing - used in embedded systems requiring robust power-up/power-down supervision and fault recovery.

For engineers reviewing the DS1831+ datasheet, DS1831+ pinout, DS1831+ application, or DS1831+ equivalent, this page delivers verified functional identity, tolerance-selectable trip points (4.00–4.75V for 5V rail; 2.47–3.15V for 3.3V rail), programmable reset delays (10ms/100ms/1s), non-maskable interrupt capability, and compatibility with mixed-supply industrial controllers and microprocessor-based instrumentation.

Technical Context

The DS1831+ uses an internal 1.25V temperature-compensated bandgap reference to compare input voltages against configurable thresholds. Its dual TOL/TD inputs enable independent tolerance selection (5%/10%/15% for 5V; 5%/10%/20% for 3.3V) and reset delay timing (10ms/100ms/1s) per supply rail, set at power-up and immutable until cycling.

Internal operation draws power from the higher of IN5V or IN3.3V (≥1.0V required), supporting valid output states even during brownout. Two NMI outputs provide hysteresis-equipped (100µV) comparator monitoring of external voltages via resistor dividers, with 10µs minimum active pulse width and noise immunity against <2µs transients.

Key Specifications

Pinout & Package

DS1831+ is supplied in a 16-pin plastic dual in-line package (DIP), 300mil width, with 0.1" lead pitch and through-hole mounting. Pin 1 is marked by a notch or dot; pin numbering follows standard counter-clockwise convention when viewed from top with notch left-aligned.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326 and TPS3808G33, DS1831+ uniquely supports simultaneous 5V/3.3V supervision with independent tolerance/delay tuning, two NMI channels for external voltage monitoring, and three pushbutton interfaces - making it irreplaceable in complex, multi-rail industrial control designs requiring hardware-level fault autonomy.

Availability

DS1831+ is available at Aetrix Electronics and suitable for industrial automation, medical instrumentation, and telecom infrastructure requiring stable component supply, long-term lifecycle assurance, and traceable sourcing for safety-critical power supervision.

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, mixed-signal, and power management ICs for industrial, automotive, and communications applications - emphasizing reliability, integration, and performance under harsh conditions.

The DS1831+ belongs to Maxim's Micromonitor™ family of power-supervisory ICs, engineered specifically for robust, hardware-based power-failure detection and recovery in multi-voltage embedded systems without software dependency.

FAQ

What is the function of the TOL5V and TOL3.3V pins on the DS1831+?

The TOL5V and TOL3.3V pins configure the voltage tolerance for the respective 5V and 3.3V supply monitors. For DS1831+, connecting TOL5V to IN5V selects ±5% tolerance (trip point 4.50–4.75V), grounding it selects ±10% (4.25–4.49V), and leaving it floating selects ±15% (4.00–4.24V). Similarly, TOL3.3V sets 3.3V tolerance at ±5%, ±10%, or ±20%. These settings are latched at power-up and remain fixed until the next power cycle. DS1831+ relies on these pins to adapt to varying supply regulation specs across target applications.

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

Yes, the DS1831+ includes two dedicated sense inputs - IN1 and IN2 - each compared to the internal 1.25V reference. By using external resistor dividers, users can scale higher voltages (e.g., 12V, 24V) down to the 1.25V threshold to generate NMI1 or NMI2 interrupts. For example, a 11.5V trip point is achieved with R1 = 820kΩ and R2 = 100kΩ. This capability allows DS1831+ to supervise auxiliary rails, battery levels, or sensor supply voltages beyond its primary 5V/3.3V monitoring role.

How does the DS1831+ handle power-up sequencing and brownout conditions?

During power-up, DS1831+ holds RST5V and RST3.3V active until their respective supplies reach valid voltage levels and remain stable for the configured time delay (10ms/100ms/1s). Under brownout, if either IN5V or IN3.3V drops below its trip point, the corresponding reset asserts and remains active for the full delay period after recovery. DS1831+ continues operating as long as ≥1.0V is present on any supply input, ensuring fail-safe behavior - a key design requirement for DS1831+ in mission-critical industrial systems.

What are the electrical requirements for the pushbutton inputs on the DS1831+?

All pushbutton inputs (PBRST5V, PBRST3.3V, MPBRST) on DS1831+ are active-low and feature internal 100kΩ pull-up resistors - to IN5V for PBRST5V, to IN3.3V for PBRST3.3V, and to the higher of IN5V/IN3.3V for MPBRST. A valid reset requires pulling the pin below 0.3×VINT for ≥20µs. No external pull-up is needed, though a 10kΩ resistor may be added to accelerate transitions. This architecture simplifies system-level reset button design while maintaining noise immunity - a consistent behavior across all DS1831+ variants.

Does the DS1831+ require external pull-up resistors on its reset outputs?

Yes, both RST5V and RST3.3V are open-drain outputs and require external pull-up resistors to establish a valid high state when inactive. A typical value is 10kΩ connected to the associated supply rail (e.g., RST5V pulled to 5V, RST3.3V pulled to 3.3V). The DS1831+ datasheet confirms this requirement for proper logic-level translation and noise margin. Without pull-ups, the reset signals cannot drive downstream logic correctly - a mandatory design consideration for every DS1831+ implementation.