Analog Devices Inc./Maxim Integrated DS1819AR-5-U+

Overview

DS1819AR-5-U+ from Maxim Integrated is a 3.3V microprocessor supervisory circuit with active-low reset output, 5% VCC trip accuracy (3.00V typ), 140ms minimum reset pulse width, watchdog timer (1.12s timeout), and pushbutton reset support. It monitors power supply integrity, software execution via strobe input, and external override in embedded microcontroller systems.

For engineers reviewing the DS1819AR-5-U+ datasheet, DS1819AR-5-U+ pinout, DS1819AR-5-U+ application, or DS1819AR-5-U+ equivalent, key selection criteria include VCC trip point tolerance, reset timing stability across -40°C to +85°C, SOT-23-5 package compatibility, and functional alignment with MAX823/24/25-series supervisory ICs.

Technical Context

The DS1819AR-5-U+ implements a precision voltage monitor with 5% trip accuracy at 3.00V nominal, temperature-compensated reference, and 5mV hysteresis. Its internal watchdog timer triggers reset if the ST strobe input fails to toggle within 1.12 seconds, and it debounces PBRST pushbutton input to generate ≥140ms active-low reset pulses.

Reset assertion occurs on VCC drop below trip threshold and persists for ≥140ms after VCC recovery; RST output uses push-pull drive capable of valid logic down to 1.0V VCC, with resistor pull-down enabling 0V operation. The device supports industrial temperature range (-40°C to +85°C) and operates from 1.0V to 5.5V supply.

Key Specifications

Pinout & Package

SOT-23-5 surface-mount package: 2.9mm × 1.6mm footprint, 1.1mm height, gull-wing leads, RoHS-compliant, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX823SEUK+T and TPS3808G15DBVR, the DS1819AR-5-U+ uniquely combines 3.3V-specific 5% trip accuracy, integrated pushbutton debounce, and watchdog functionality in a single SOT-23-5 package-reducing component count and layout complexity for compact 3.3V microcontroller systems.

Availability

DS1819AR-5-U+ is available at Aetrix Electronics and suitable for industrial automation, smart metering, medical handhelds, and automotive body electronics requiring stable component supply and long-term lifecycle support.

Supply support for DS1819AR-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) designs precision analog, mixed-signal, and power management ICs for industrial, automotive, communications, and computing applications.

The DS1819AR-5-U+ belongs to the MicroMonitor™ family of supervisory ICs engineered specifically for robust, low-power microprocessor reset and watchdog control in 3.3V embedded systems.

FAQ

What is the exact VCC trip point and tolerance for DS1819AR-5-U+?

The DS1819AR-5-U+ has a nominal VCC trip point of 3.00V with ±5% tolerance (2.85V to 3.15V), verified across -40°C to +85°C. This specification applies specifically to the 'R-5' variant denoting 5% accuracy, and is measured under recommended operating conditions with VCC between 1.2V and 5.5V. The DS1819AR-5-U+ uses an internal temperature-compensated reference to maintain this accuracy without external components.

Does DS1819AR-5-U+ support both watchdog and pushbutton reset functions simultaneously?

Yes, the DS1819AR-5-U+ supports both functions concurrently: Pin 4 (ST) serves as the watchdog strobe input, and Pin 3 (PBRST) serves as the debounced pushbutton reset input. These operate independently-the watchdog resets RST on ST timeout, while PBRST generates RST on button release. Both trigger the same 140ms minimum active-low reset pulse, and neither function disables the other in the DS1819AR-5-U+ 'A' version.

What is the minimum VCC required for DS1819AR-5-U+ to assert a valid RST signal?

The DS1819AR-5-U+ RST output remains valid down to 1.0V VCC using its internal push-pull driver. To extend validity to 0V, a 100kΩ pull-down resistor from RST to GND is recommended per the datasheet. This configuration ensures monotonic reset behavior during full power-down sequences, a critical requirement for flash-safe operation in the DS1819AR-5-U+.

Is DS1819AR-5-U+ pin-compatible with MAX823 series devices?

Yes, DS1819AR-5-U+ is pin- and function-compatible with the MAX823/24/25 family in SOT-23-5 package, as confirmed in the official datasheet. Pin mapping (RST, GND, PBRST, ST, VCC) matches identically, and electrical timing parameters-including 140ms reset width and 1.12s watchdog timeout-are aligned. However, DS1819AR-5-U+ is optimized for 3.3V systems, whereas MAX823 variants target 5V operation.

What industrial temperature performance is guaranteed for DS1819AR-5-U+?

The DS1819AR-5-U+ is fully specified and tested over -40°C to +85°C ambient temperature. All key parameters-including VCC trip point (3.00V ±5%), reset pulse width (140–280ms), watchdog timeout (1.12–2.40s), and operating current (8–12μA)-are guaranteed across this range. This makes the DS1819AR-5-U+ suitable for uncontrolled environments such as factory floors, outdoor meters, and vehicle cabins where thermal stability is essential.