Analog Devices Inc./Maxim Integrated DS1819CR-5+T&R

Overview

DS1819CR-5+T&R from Maxim Integrated is a 3.3V microprocessor supervisory circuit in SOT-23-5 package, featuring active-low reset output, pushbutton reset input, and watchdog timer with 1.12s timeout. It monitors VCC trip point at 3.00–3.15V (±5%), provides 140ms minimum reset pulse width, and operates across –40°C to +85°C for embedded control systems requiring reliable power-up/power-down sequencing.

For engineers reviewing the DS1819CR-5+T&R datasheet, DS1819CR-5+T&R pinout, DS1819CR-5+T&R application, or DS1819CR-5+T&R equivalent, key selection criteria include VCC trip accuracy (±5% @ 3V), pushbutton debounce support, watchdog strobe timing tolerance, and compatibility with MAX823/24/25-series designs in space-constrained industrial controllers.

Technical Context

The DS1819CR-5+T&R implements a precision bandgap reference and comparator for VCC monitoring, with 5mV hysteresis and valid RST output down to 1.0V VCC. Its watchdog timer resets on ST input transitions every ≤1.12s and disables when ST is floating.

This 'C' variant integrates both PBRST (pin 4) and active-high RST (pin 3), enabling dual-reset signaling while maintaining pushbutton debouncing and 140ms minimum active reset duration during power transients or manual override.

Key Specifications

Pinout & Package

SOT-23-5 surface-mount package with 1.6mm × 2.9mm footprint, 0.95mm height, and gull-wing leads compatible with standard reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX823SEUK+T and TPS3808G33DBVR, the DS1819CR-5+T&R uniquely combines 3.3V ±5% trip accuracy, integrated pushbutton debounce, dual-reset outputs, and watchdog timer in one SOT-23-5 device-enabling compact, self-contained supervision without external components or firmware dependency.

Availability

DS1819CR-5+T&R is available at Aetrix Electronics and suitable for industrial automation, medical diagnostics, automotive body electronics, and smart metering applications requiring stable component supply and long-term lifecycle support.

Supply support for DS1819CR-5+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 demanding industrial, automotive, and communications applications.

The DS1819CR-5+T&R belongs to the MicroMonitor family, engineered specifically to provide integrated power monitoring, watchdog supervision, and pushbutton reset control for 3.3V microprocessor systems in harsh environments.

FAQ

What is the VCC trip point tolerance for DS1819CR-5+T&R?

The DS1819CR-5+T&R has a ±5% VCC trip point tolerance, specified as 3.00V to 3.15V at 25°C. This tight accuracy ensures consistent reset assertion before 3.3V system rails fall below operational thresholds, critical for preventing undefined microprocessor behavior during brownout events. The DS1819CR-5+T&R achieves this using an internal temperature-compensated bandgap reference and comparator circuit.

Does DS1819CR-5+T&R support both active-low and active-high reset outputs?

Yes, the DS1819CR-5+T&R provides simultaneous active-low RST (pin 1) and active-high RST (pin 3) outputs. This dual-output architecture allows direct connection to microcontrollers requiring either polarity without external inverters. The DS1819CR-5+T&R asserts both outputs synchronously during power faults, watchdog timeouts, or pushbutton events, ensuring deterministic system reset behavior.

How does the watchdog timer function in DS1819CR-5+T&R?

The DS1819CR-5+T&R watchdog timer requires a transition on the ST input (pin 4) at least every 1.12 seconds to prevent timeout. If no edge occurs, it forces both RST outputs active for ≥140ms. The timer disables automatically when ST is left floating. This behavior is confirmed in the device's functional description and timing diagrams, and applies specifically to DS1819CR-5+T&R as a 'C' variant with ST pin present.

Can DS1819CR-5+T&R operate below 3.0V VCC?

Yes, the DS1819CR-5+T&R maintains valid RST output down to 1.0V VCC, per its DC electrical characteristics. Below 1.0V, a 100kΩ pull-down resistor from RST to GND extends validity to 0V. This feature ensures reliable reset assertion during deep brownout or battery depletion, a documented capability unique to the DS1819CR-5+T&R among comparable supervisors.

Is DS1819CR-5+T&R pin-compatible with MAX823-series devices?

Yes, the DS1819CR-5+T&R is explicitly stated as pin- and function-compatible with MAX823/24/25 products. Pin mapping matches exactly: RST (1), GND (2), RST (3), PBRST (4), VCC (5). This compatibility enables drop-in replacement in existing designs targeting 3.3V operation, provided the original design used a 'C' variant with pushbutton and dual-reset support.