Analog Devices Inc./Maxim Integrated DS1819CR-5-U

Overview

DS1819CR-5-U from Maxim Integrated is a 3.3V microprocessor supervisory circuit in SOT-23-5 package, providing precision power monitoring (±5% trip point at 3.00 V), watchdog timer (1.12 s timeout), and pushbutton reset with 140 ms minimum active-reset pulse width. It halts and restarts out-of-control microprocessors during power transients or software lockup in embedded industrial controllers.

For engineers reviewing the DS1819CR-5-U datasheet, DS1819CR-5-U pinout, DS1819CR-5-U application, or DS1819CR-5-U equivalent, key selection criteria include its 3.00 V ±5% VCC trip point, 140 ms reset timeout, push-pull RST output valid down to 1.0 V VCC, and compatibility with MAX823/24/25 functional equivalents in space-constrained designs.

Technical Context

The DS1819CR-5-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 control on PBRST. Its RST output remains valid down to 1.0 V VCC via push-pull drive.

It operates across -40°C to +85°C, draws only 8–12 µA typical supply current at 3.6 V, and features internal 50 kΩ pull-up on PBRST. The device supports both active-low and active-high reset outputs depending on variant-DS1819CR-5-U is a 'C' version, delivering RST (active-low) and RST (active-high) simultaneously.

Key Specifications

Pinout & Package

SOT-23-5 surface-mount package (2.9 mm × 1.6 mm × 1.1 mm), lead-free and RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX823SEUK+T and TPS3808G33DBVR, the DS1819CR-5-U uniquely delivers 3.3 V ±5% monitoring, integrated pushbutton debounce, and simultaneous active-low/active-high reset outputs in a single SOT-23-5 package-enabling compact, robust supervision without external components.

Availability

DS1819CR-5-U is available at Aetrix Electronics and suitable for industrial PLC controllers, smart metering modules, medical sensor nodes, and automotive body control modules requiring stable component supply and long-term lifecycle support.

Supply support for DS1819CR-5-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, communications, and consumer applications.

The DS1819CR-5-U belongs to the MicroMonitor™ family, designed specifically for reliable microprocessor supervision in 3.3 V embedded systems where power integrity, software watchdog, and manual reset must coexist in minimal footprint.

FAQ

What is the exact VCC trip point tolerance for DS1819CR-5-U?

The DS1819CR-5-U has a nominal VCC trip point of 3.00 V with ±5% tolerance, meaning it asserts reset when VCC falls below 2.85 V (min) and releases reset when VCC rises above 3.15 V (max). This 5% specification is confirmed in the DC Electrical Characteristics table under "VCC Trip Point DS1819-5" and applies across the full -40°C to +85°C operating range.

Does DS1819CR-5-U support both active-low and active-high reset outputs?

Yes, DS1819CR-5-U is a 'C' variant and 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 reset events, enabling direct interface to MCUs requiring either polarity without external logic.

Can the watchdog timer in DS1819CR-5-U be disabled?

Yes, the watchdog timer in DS1819CR-5-U can be disabled by leaving the ST (strobe) input floating or tri-stated. When ST is not driven, the watchdog remains inactive and does not generate reset pulses. This allows flexible use in systems where only power monitoring and pushbutton reset are needed.

What is the minimum VCC level at which DS1819CR-5-U maintains valid RST output?

The DS1819CR-5-U maintains valid RST and RST output down to 1.0 V VCC due to its push-pull output stage. Below 1.0 V, 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-5-U pin-compatible with MAX823 series devices?

Yes, DS1819CR-5-U is pin- and function-compatible with the MAX823/24/25 family per manufacturer documentation. It shares identical SOT-23-5 pinout, reset timing, and functional blocks-enabling direct substitution in existing layouts without PCB modification or firmware changes.