Analog Devices Inc./Maxim Integrated DS1819CR-10-U+

Overview

DS1819CR-10-U+ from Maxim Integrated is a 3.3V microprocessor supervisory circuit with active-low reset output, pushbutton reset input, and watchdog timer functionality. It monitors VCC (trip point 2.85–3.00 V), provides 140–280 ms reset pulse width, and operates across –40°C to +85°C in SOT-23-5 package. It is used in embedded systems requiring reliable power-up sequencing and software fault recovery.

For engineers reviewing the DS1819CR-10-U+ datasheet, DS1819CR-10-U+ pinout, DS1819CR-10-U+ application, or DS1819CR-10-U+ equivalent, key selection criteria include its 10% VCC threshold tolerance, 1.12 s watchdog timeout, push-pull RST output valid down to 1.0 V VCC, and compatibility with 3.0 V microcontroller power rails.

Technical Context

The DS1819CR-10-U+ implements a precision voltage monitor with 5 mV hysteresis, a 1.12 s watchdog timer triggered by ST input transitions, and a debounced PBRST input that generates ≥140 ms active-low reset pulses on button release. Its RST output uses a push-pull driver capable of sourcing 350 µA and sinking 3.2–6 mA.

It supports three core supervision functions: power-fail detection (VCC < 2.85 V), external manual reset via PBRST, and software execution monitoring via ST strobe. The device disables watchdog when ST is floating, and maintains reset assertion for ≥140 ms after VCC recovery to ensure processor stabilization.

Key Specifications

Pinout & Package

SOT-23-5 surface-mount package (2.9 mm × 1.6 mm × 1.1 mm), lead-free and RoHS-compliant, optimized for space-constrained PCB layouts.

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 DS1819CR-10-U+ uniquely integrates 3.0 V-specific monitoring, pushbutton reset, and watchdog in one SOT-23-5 package - eliminating discrete support components and simplifying layout for compact 3.3 V embedded systems.

Availability

DS1819CR-10-U+ is available at Aetrix Electronics and suitable for industrial automation, medical instrumentation, automotive body electronics, and smart metering applications requiring stable component supply and long-term lifecycle support.

Supply support for DS1819CR-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) is a semiconductor company specializing in analog, mixed-signal, and power management ICs for industrial, automotive, and communications markets.

The DS1819CR-10-U+ belongs to the MicroMonitor™ family - designed specifically for microprocessor supervision in resource-constrained embedded systems requiring guaranteed reset timing, low power, and multi-function integration.

FAQ

What is the exact VCC trip point range for DS1819CR-10-U+?

The DS1819CR-10-U+ has a guaranteed VCC trip point of 2.85 V (min) to 3.00 V (max), corresponding to its 10% tolerance rating for 3.0 V systems. This range is specified over the full industrial temperature range (–40°C to +85°C) and ensures consistent brownout detection without external calibration. The device uses an internal temperature-compensated reference to maintain accuracy across operating conditions.

Does DS1819CR-10-U+ support both active-low and active-high reset outputs?

Yes, DS1819CR-10-U+ provides dual reset outputs: Pin 1 (RST) is active-low, and Pin 3 (RST) is active-high. Both are push-pull drivers, eliminating the need for external pull-up or pull-down resistors. This allows direct interfacing with microcontrollers requiring either polarity, and supports redundancy or logic-level translation in mixed-voltage systems.

How does the watchdog function work on DS1819CR-10-U+ and what is its timeout period?

The DS1819CR-10-U+ watchdog timer requires a logic transition on the ST pin (Pin 4) at least every 1.12 seconds (typical). If no transition occurs, it asserts RST and RST for ≥140 ms. The timer resets on each ST edge and starts timing out only after reset deassertion. Watchdog can be disabled by leaving ST floating - no external components or configuration required.

Can DS1819CR-10-U+ operate below 3.0 V, and how low will RST remain valid?

Yes, DS1819CR-10-U+ operates down to 1.0 V VCC, and its RST output remains valid (logic-low or logic-high) across that entire range. Below 1.0 V, adding a 100 kΩ pull-down resistor from RST to GND extends validity to 0 V VCC - critical for fail-safe behavior during complete power collapse in battery-backed systems.

Is DS1819CR-10-U+ pin-compatible with other devices in the DS181x family?

DS1819CR-10-U+ is pin-compatible with DS1819A, DS1819B, and DS1819C variants in the same SOT-23-5 package, sharing identical pin assignments. However, functionality differs: DS1819CR-10-U+ ('C' version) includes both PBRST and RST pins, whereas 'A' lacks RST and 'B' lacks PBRST. Always verify variant suffix against functional requirements before substitution.