Analog Devices Inc./Maxim Integrated DS1819AR-20+T&R

Overview

DS1819AR-20+T&R from Maxim Integrated is a 3.3V microprocessor supervisory circuit with watchdog timer, pushbutton reset control, and precise power monitoring. It provides active-low reset output (RST), strobe input (ST), pushbutton reset input (PBRST), and operates over -40°C to +85°C. Its 20% VCC trip point (2.55–2.70 V) targets 3.0V systems in industrial embedded controllers.

For engineers reviewing the DS1819AR-20+T&R datasheet, DS1819AR-20+T&R pinout, DS1819AR-20+T&R application, or DS1819AR-20+T&R equivalent, key selection criteria include reset timeout (140–280 ms), watchdog timeout (1.12–2.40 s), VCC trip accuracy (±20%), SOT-23-5 package compatibility, and functional alignment with MAX823/24/25 series.

Technical Context

The DS1819AR-20+T&R implements a precision voltage monitor with 5 mV hysteresis, a 1.12 s watchdog timer triggered by ST input transitions, and debounced pushbutton reset logic on PBRST. Its RST output uses a push-pull driver valid down to 1.0 V VCC and supports 0 V operation with external pull-down.

It integrates three independent supervision functions-power-fail detection, software execution monitoring via ST, and manual override via PBRST-within a single SOT-23-5 IC. The 'A' variant confirms presence of both ST and PBRST pins, distinguishing it from 'B' (ST only) and 'C' (PBRST + RST high) versions.

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 industrial PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX823SEUK+T and TPS3808G12DBVR, DS1819AR-20+T&R uniquely combines 3V-specific ±20% monitoring, integrated watchdog, and pushbutton reset in one SOT-23-5 package-reducing BOM count and PCB area where multi-function supervision is mandatory.

Availability

DS1819AR-20+T&R is available at Aetrix Electronics and suitable for industrial PLC controllers, smart metering modules, medical handheld diagnostics, and automotive body control modules requiring stable component supply and long-term manufacturability.

Supply support for DS1819AR-20+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, medical, and communications applications.

The DS1819AR-20+T&R belongs to the MicroMonitor™ family-engineered specifically for robust, multi-condition supervision of 3.0V/3.3V microcontrollers in harsh environments where power integrity, software reliability, and field serviceability are critical.

FAQ

What is the VCC trip point range for DS1819AR-20+T&R?

The DS1819AR-20+T&R has a guaranteed VCC trip point of 2.55 V to 2.70 V, corresponding to its ±20% tolerance specification for 3.0V systems. This range is validated across -40°C to +85°C and ensures reliable power-fail detection before the microcontroller enters undefined operation. The DS1819AR-20+T&R uses an internal temperature-compensated reference to maintain accuracy across its full operating temperature range.

Does DS1819AR-20+T&R support watchdog functionality?

Yes, DS1819AR-20+T&R supports watchdog functionality via its ST (strobe) input. When enabled, the internal timer forces RST active if ST does not toggle within 1.12 seconds. The watchdog can be disabled by leaving ST floating or tri-stated-no external components required. This behavior is confirmed for the 'A' variant, which includes both ST and PBRST pins as specified in the DS1819A pin assignment.

Can DS1819AR-20+T&R drive a microcontroller reset pin directly?

Yes, DS1819AR-20+T&R drives reset pins directly using a push-pull output capable of sourcing 350 µA at 2.4V and sinking 3.2–6 mA at 0.4V. Its RST output remains valid down to 1.0V VCC, and with an optional 100 kΩ pull-down resistor, it sustains defined logic levels even at 0V VCC-enabling safe, deterministic reset assertion during full power collapse.

Is DS1819AR-20+T&R pin-compatible with MAX823 series devices?

Yes, DS1819AR-20+T&R is pin- and function-compatible with the MAX823/24/25 family for 3V applications. It shares identical SOT-23-5 pinout (RST, GND, PBRST, ST, VCC), reset timing (140–280 ms), and functional blocks-including power monitoring, watchdog, and pushbutton reset. This compatibility enables drop-in replacement in existing designs targeting 3.0V systems without PCB or firmware changes.

What is the operating current consumption of DS1819AR-20+T&R?

The DS1819AR-20+T&R consumes 8–12 µA typical operating current across -40°C to +85°C at VCC = 3.6V, as specified in the DC Electrical Characteristics table. This ultra-low quiescent current makes it suitable for battery-powered or energy-harvesting applications where standby power budget is constrained. The DS1819AR-20+T&R achieves this efficiency while maintaining full supervision functionality-including active watchdog and pushbutton debounce logic.