Analog Devices Inc./Maxim Integrated DS1819AR-10-U

Overview

DS1819AR-10-U from Maxim Integrated is a 3.3V microprocessor supervisory circuit with watchdog timer, pushbutton reset control, and precision power monitoring. It provides active-low reset output (RST), strobe input (ST), and pushbutton reset input (PBRST); features 10% VCC trip point (2.85–3.00 V), 140ms minimum reset pulse width, and operates from 1.0V to 5.5V supply. Used in embedded systems requiring reliable power-up sequencing and software fault recovery.

For engineers reviewing the DS1819AR-10-U datasheet, DS1819AR-10-U pinout, DS1819AR-10-U application, or DS1819AR-10-U equivalent, key selection criteria include its 3V-specific voltage threshold accuracy, SOT-23-5 package compatibility with MAX823/24/25, watchdog timeout of 1.12s, and dual reset output capability in 'A' variant configuration.

Technical Context

The DS1819AR-10-U implements a precision bandgap-based voltage monitor with 5mV hysteresis for stable 3.0V system detection, combined with an internal watchdog timer that triggers reset if ST input fails to toggle within 1.12 seconds. Its RST output uses push-pull logic valid down to 1.0V VCC, enabling robust reset assertion during brown-out conditions.

This 'A' variant integrates both PBRST (debounced pushbutton reset) and ST (watchdog strobe) inputs, delivering active-low RST output only - matching DS1819A functional definition. It supports industrial temperature range (−40°C to +85°C) and draws only 8–12µA typical operating current at 3.6V.

Key Specifications

Pinout & Package

SOT-23-5 surface-mount package: 2.9mm × 1.6mm footprint, 1.1mm height, lead pitch 0.95mm; thermally enhanced for compact PCB layouts and automated assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX823SEUK+T and TPS3808G12DBVR, the DS1819AR-10-U uniquely combines 3.0V-specific accuracy, integrated pushbutton debouncing, and configurable watchdog in one ultra-low-power SOT-23-5 device - eliminating three discrete functions while maintaining pin compatibility with industry-standard supervisory ICs.

Availability

DS1819AR-10-U is available at Aetrix Electronics and suitable for industrial automation, medical instrumentation, smart metering, and automotive body electronics requiring stable component supply across extended product lifecycles.

Supply support for DS1819AR-10-U 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 demanding industrial, medical, and communications applications.

The DS1819AR-10-U belongs to Maxim's MicroMonitor™ family - engineered specifically for microprocessor supervision in 3V embedded systems where accurate voltage thresholding, watchdog safety, and hardware reset control are critical.

FAQ

What is the exact VCC trip point range for DS1819AR-10-U?

The DS1819AR-10-U has a guaranteed VCC trip point range of 2.85 V to 3.00 V at −40°C to +85°C, corresponding to its 10% tolerance rating for nominal 3.0V systems. This specification is validated per Maxim's DC Electrical Characteristics table and applies across full industrial temperature range and supply voltage (1.0–5.5V).

Does DS1819AR-10-U provide both active-high and active-low reset outputs?

No, DS1819AR-10-U is an 'A' variant and provides only an active-low RST output (Pin 1). The DS1819B and DS1819C variants offer active-high RST on Pin 3, but DS1819AR-10-U does not include that second output. Its functional block diagram and pin assignment confirm RST as sole reset signal.

Can the watchdog timer in DS1819AR-10-U be disabled, and how?

Yes, the watchdog timer in DS1819AR-10-U can be disabled by leaving the ST input (Pin 4) floating or tri-stated. The datasheet explicitly states that "the watchdog can be disabled by floating (or tri-stating) the ST input," and no external components are required. Driving ST continuously high or low will also prevent timeout but consumes additional current.

What is the minimum reset pulse width generated by DS1819AR-10-U?

The DS1819AR-10-U guarantees a minimum reset pulse width of 140 ms for all reset sources - including power-up, power-down, pushbutton release, and watchdog timeout. This value is specified in the AC Electrical Characteristics table and ensures sufficient time for microprocessor core and peripheral initialization before release.

Is DS1819AR-10-U compatible with 1.8V microcontrollers?

Yes, DS1819AR-10-U operates with VCC as low as 1.0V and maintains valid RST output down to 1.0V, making it compatible with 1.8V systems when powered from the same rail. However, its 2.85–3.00V trip point is optimized for 3.0V monitoring; for 1.8V supervision, a different variant or adjustable supervisor would be required.