Analog Devices Inc./Maxim Integrated DS1819AR-5+T&R

Overview

DS1819AR-5+T&R from Maxim Integrated is a 3.3V microprocessor supervisory circuit in SOT-23-5 package, featuring 5% VCC trip point (3.00–3.15V), 140ms minimum reset pulse width, watchdog timeout of 1.12s, and pushbutton reset input with internal debouncing. It halts and restarts out-of-control microprocessors during power transients or software lockup in embedded control systems.

For engineers reviewing the DS1819AR-5+T&R datasheet, DS1819AR-5+T&R pinout, DS1819AR-5+T&R application, or DS1819AR-5+T&R equivalent, key selection criteria include 3V supply monitoring accuracy, active-low reset output drive capability down to 1.0V VCC, watchdog strobe timing compliance, and compatibility with industrial-temperature microcontroller power domains.

Technical Context

The DS1819AR-5+T&R implements a precision voltage monitor with 5mV hysteresis, a 1.12s watchdog timer triggered by ST input transitions, and a debounced PBRST input that generates a guaranteed 140ms active-low reset pulse on button release. Its push-pull RST output remains valid down to 1.0V VCC, enabling robust reset assertion during brownout conditions.

This 'A' variant integrates both watchdog (ST pin) and pushbutton reset (PBRST pin) functions, distinguishing it from 'B' (watchdog + active-high RST) and 'C' (pushbutton + active-high RST) variants. The device operates across -40°C to +85°C and draws only 8–12μA typical quiescent current at 3.6V.

Key Specifications

Pinout & Package

SOT-23-5 surface-mount package with 1.6mm × 2.9mm footprint, 0.95mm height, and gull-wing leads. RoHS-compliant, lead-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX823SESA+ and TPS3808G12DBVR, the DS1819AR-5+T&R uniquely combines 3.3V-optimized voltage monitoring, hardware watchdog, and pushbutton reset in one SOT-23-5 package-reducing BOM count and PCB area while guaranteeing deterministic reset behavior without firmware dependency.

Availability

DS1819AR-5+T&R is available at Aetrix Electronics and suitable for industrial PLC controllers, medical infusion pumps, smart energy meters, and automotive body control modules requiring stable component supply and long-term lifecycle support.

Supply support for DS1819AR-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 high-performance analog and mixed-signal ICs for industrial, medical, and communications applications.

The DS1819AR-5+T&R belongs to the MicroMonitor™ family, engineered specifically for reliable microprocessor supervision in harsh environments where power integrity and software execution monitoring are mission-critical.

FAQ

What is the exact VCC trip point range for DS1819AR-5+T&R?

The DS1819AR-5+T&R has a guaranteed VCC trip point of 3.00V to 3.15V, reflecting its 5% tolerance specification for 3.3V systems. This range is factory-trimmed and tested across -40°C to +85°C, ensuring consistent brownout detection without external calibration. The DS1819AR-5+T&R uses an internal temperature-compensated reference to maintain accuracy over full operating temperature.

Does DS1819AR-5+T&R support both watchdog and pushbutton reset simultaneously?

Yes, the DS1819AR-5+T&R is the 'A' variant, which integrates both functions: ST pin provides watchdog strobe input with 1.12s timeout, and PBRST pin accepts active-low pushbutton signals with hardware debouncing and 140ms minimum reset pulse generation. Both features operate independently and can trigger RST concurrently without conflict.

Can DS1819AR-5+T&R operate below 3.0V VCC?

Yes - the DS1819AR-5+T&R functions down to 1.0V VCC, and its RST output remains valid (logic-low or logic-high) across that range. Below 1.0V, a 100kΩ pull-down resistor from RST to GND extends valid reset assertion to 0V VCC, enabling fail-safe behavior during complete power collapse. This feature is explicitly verified in the DS1819AR-5+T&R datasheet Figure 9.

Is DS1819AR-5+T&R pin-compatible with MAX823 series devices?

Yes, the DS1819AR-5+T&R is pin- and function-compatible with the MAX823/24/25 family per manufacturer documentation. Pin 1 (RST), Pin 2 (GND), Pin 4 (ST), and Pin 5 (VCC) map identically; Pin 3 is PBRST on DS1819AR-5+T&R versus RST (active-high) on MAX823 variants. System-level compatibility requires verifying whether active-high reset is needed - otherwise, DS1819AR-5+T&R serves as a drop-in replacement for 3.3V applications.

What is the maximum recommended VCC slew rate for DS1819AR-5+T&R during power-up?

The DS1819AR-5+T&R specifies a minimum VCC slew rate of 12.5 V/s during rising edge to ensure reliable power-on reset timing. Slower ramps may cause premature RST deassertion before the microprocessor's internal regulators stabilize. This requirement is documented in the AC Electrical Characteristics table and validated across -40°C to +85°C. For systems with slower power rails, external RC delay on VCC or use of the DS1819AR-5+T&R's 140ms tRPU parameter ensures robust initialization.