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

Overview

DS1819CR-10-U from Maxim Integrated is a 3.3V microprocessor supervisory circuit that monitors VCC, implements watchdog timer functionality (ST input), and supports pushbutton reset (PBRST input). It features 10% VCC trip point accuracy (2.85–3.00 V), 140 ms minimum reset pulse width, and operates across –40°C to +85°C in SOT-23-5 package. 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 2.85–3.00 V reset threshold, 1.12 s watchdog timeout, push-pull RST output valid down to 1.0 V VCC, and compatibility with 3.0 V microcontroller supply rails.

Technical Context

The DS1819CR-10-U integrates three core supervision functions: precision voltage monitoring using a temperature-compensated bandgap reference and comparator, a 1.12 s watchdog timer triggered by ST input transitions, and debounced pushbutton reset via PBRST. Its dual-reset outputs (RST active-low and RST active-high) support diverse processor interface requirements.

It delivers guaranteed reset assertion during VCC transients, holds reset active for ≥140 ms after power recovery, and maintains valid RST logic levels down to 1.0 V VCC via push-pull output - enabling robust operation during brownout and power-down sequences without external pull-ups.

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 MAX823SEUR+T and TPS3808G12DBVR, the DS1819CR-10-U uniquely combines 3.0 V system optimization, integrated PBRST debouncing, and ST-based watchdog in a 5-pin SOT-23 - delivering pin-compatible supervision for cost-sensitive industrial 3.3 V microcontrollers without external components.

Availability

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

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) designs precision analog, mixed-signal, and power management ICs for demanding industrial, medical, and communications applications.

The DS1819CR-10-U belongs to the MicroMonitor™ family - engineered specifically for reliable microprocessor supervision in 3.3 V embedded systems, emphasizing low-power operation, noise-immune reset generation, and integrated fault-detection functions.

FAQ

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

The DS1819CR-10-U has a guaranteed VCC trip point range of 2.85 V to 3.00 V, corresponding to its 10% tolerance specification for 3.0 V systems. This threshold is set by an internal precision temperature-compensated reference and comparator, ensuring consistent reset assertion before microprocessor functional failure occurs. The hysteresis is 5 mV, minimizing chatter near the trip point.

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

Yes, the DS1819CR-10-U provides two independent reset outputs: Pin 1 (RST) is active-low, and Pin 3 (RST) is active-high. Both outputs are asserted simultaneously during power failure, watchdog timeout, or pushbutton release. This dual-output architecture eliminates the need for external inverters when interfacing with MCUs requiring either polarity, simplifying board design and improving signal integrity.

How is the watchdog function enabled or disabled on DS1819CR-10-U?

The watchdog timer in DS1819CR-10-U is enabled by driving the ST input (Pin 4) with periodic transitions - it must toggle at least once every 1.12 seconds. To disable the watchdog, leave the ST pin unconnected (floating) or tri-state it; no external pull-up/down is required. The device automatically disables the watchdog when ST is inactive, allowing flexible use in systems where software supervision is optional or conditional.

Can DS1819CR-10-U operate reliably below 3.0 V, and down to what VCC level does RST remain valid?

Yes, the DS1819CR-10-U operates over 1.0 V to 5.5 V. Critically, its push-pull RST output remains logic-valid down to 1.0 V VCC - meaning it can drive a defined low or high state even during severe brownout. Below 1.0 V, a 100 kΩ pull-down resistor from RST to GND extends validity to 0 V VCC, supporting fail-safe shutdown in ultra-low-voltage scenarios without compromising reset reliability.

Is DS1819CR-10-U pin-compatible with other members of the DS181x family?

Yes, DS1819CR-10-U is pin- and function-compatible with DS1814/DS1819 'A', 'B', and 'C' variants in SOT-23-5 package. All share identical pin assignments: RST (1), GND (2), RST (3), PBRST (4), VCC (5). However, functionality differs by suffix - DS1819CR-10-U includes both PBRST and RST (active-high), matching the 'C' variant configuration, and is not compatible with 'B'-only or 'A'-only versions in applications requiring both features.