Analog Devices Inc./Maxim Integrated DS1819CR-10/T&R

Overview

DS1819CR-10/T&R from Maxim Integrated is a 3.3V microprocessor supervisory circuit in SOT-23-5 package, providing active-low reset output, pushbutton reset input, and watchdog timer functionality. It monitors VCC with ±10% accuracy (trip point 2.85V–3.00V), delivers 140ms minimum reset pulse width, and operates across –40°C to +85°C for embedded control in power-constrained systems.

For engineers reviewing the DS1819CR-10/T&R datasheet, DS1819CR-10/T&R pinout, DS1819CR-10/T&R application, or DS1819CR-10/T&R equivalent, key selection criteria include VCC trip tolerance, reset timing consistency, pushbutton debounce behavior, watchdog timeout (1.12s), and compatibility with 3.3V microcontroller power rails and I/O logic levels.

Technical Context

The DS1819CR-10/T&R implements a precision voltage monitor with 5mV hysteresis, a 1.12s watchdog timer triggered by ST input transitions, and internal pushbutton debouncing with 140ms active reset assertion. Its RST output uses a push-pull driver capable of valid logic down to 1.0V VCC, and PBRST is internally pulled up to VCC via ~50kΩ.

It belongs to the DS181x family where 'C' denotes dual-reset output (RST active-low + RST active-high) and 'R' indicates the -10% VCC trip variant. The device requires no external components for basic operation and supports watchdog disable via floating ST input.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX823TEUK+T and TPS3808G12DBVR, the DS1819CR-10/T&R uniquely integrates pushbutton reset, dual-reset outputs, and watchdog timer in a 5-pin 3.3V-optimized package-reducing BOM count and PCB area while enabling robust, self-contained supervision for modern low-voltage microcontrollers.

Availability

DS1819CR-10/T&R is available at Aetrix Electronics and suitable for industrial automation, smart metering, medical sensing, and automotive body electronics requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for DS1819CR-10/T&R 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, communications, and computing applications.

The DS1819CR-10/T&R belongs to the MicroMonitor™ supervisory IC product line, engineered specifically to provide integrated power monitoring, reset generation, and watchdog protection for 3.3V microcontroller systems in harsh or space-constrained environments.

FAQ

What is the exact VCC trip point range for DS1819CR-10/T&R?

The DS1819CR-10/T&R has a guaranteed VCC trip point range of 2.85V to 3.00V, corresponding to ±10% tolerance around the nominal 3.0V threshold. This specification is validated over the full –40°C to +85°C temperature range and ensures reliable reset assertion before a 3.3V system enters an undefined operational state. The DS1819CR-10/T&R achieves this using a precision temperature-compensated bandgap reference and comparator circuit.

Does DS1819CR-10/T&R support both active-low and active-high reset outputs?

Yes, the DS1819CR-10/T&R provides two independent reset outputs: Pin 1 (RST) is active-low, and Pin 3 (RST) is active-high. This dual-output architecture eliminates the need for external inverters when interfacing with mixed-logic families or legacy peripherals requiring opposite reset polarity. Both outputs assert simultaneously during power-up, VCC fault, watchdog timeout, or pushbutton event, with identical 140ms minimum pulse width.

How does the watchdog timer in DS1819CR-10/T&R function, and can it be disabled?

The DS1819CR-10/T&R watchdog timer triggers a reset if the ST input (Pin 4) fails to toggle within 1.12 seconds. Time-out begins when reset outputs go inactive, and each ST transition resets the timer. The watchdog can be fully disabled by leaving the ST pin unconnected (floating) or tri-stated-no external components are needed. This behavior is confirmed in the device's functional description and timing diagrams.

What is the role of the PBRST pin on DS1819CR-10/T&R, and how is it used?

The PBRST pin (Pin 4) on DS1819CR-10/T&R accepts an active-low pushbutton signal and internally debounces it to generate a clean 140ms minimum reset pulse on both RST outputs. It features an internal ~50kΩ pull-up to VCC, so only a momentary switch between PBRST and GND is required. This eliminates external RC networks and ensures noise-immune manual reset initiation without firmware involvement.

Is DS1819CR-10/T&R compatible with 1.8V or 2.5V microcontrollers?

No, the DS1819CR-10/T&R is specified for 3.3V systems only, with VCC operating range of 1.0V to 5.5V but calibrated trip point centered at 3.0V (±10%). While it functions down to 1.0V VCC and maintains valid RST output down to that level, its voltage-monitoring accuracy and hysteresis are optimized for 3.3V rails. For 1.8V or 2.5V systems, dedicated supervisors like DS1812-18 or TPS3808G01 are recommended instead of DS1819CR-10/T&R.