Analog Devices Inc./Maxim Integrated DS1819BR-10+T&R

Overview

DS1819BR-10+T&R from Maxim Integrated is a 3.3V microprocessor supervisory circuit in SOT-23-5 package, providing precision power monitoring (2.85V–3.00V trip), watchdog timer (1.12s timeout), and active-low reset output. It halts and restarts out-of-control microprocessors during power transients or software lockup, and supports pushbutton override via debounced PBRST input. Used in embedded industrial controllers requiring reliable brownout and watchdog protection.

For engineers reviewing the DS1819BR-10+T&R datasheet, DS1819BR-10+T&R pinout, DS1819BR-10+T&R application, or DS1819BR-10+T&R equivalent, key selection criteria include VCC trip accuracy (±10% at 3V), 140ms minimum reset pulse width, watchdog strobe timing compatibility, and SOT-23-5 footprint constraints for space-constrained PCB layouts.

Technical Context

The DS1819BR-10+T&R implements a precision voltage monitor with 5mV hysteresis and temperature-compensated reference, ensuring stable reset assertion across –40°C to +85°C. Its internal watchdog timer requires ST input toggling every 1.12 seconds to prevent timeout-induced reset activation.

This variant ('B' type) provides RST (active-low) and RST (active-high) outputs, supports VCC operation from 1.0V to 5.5V, and features push-pull RST output valid down to 1.0V VCC - enabling robust reset signaling during deep power-down sequences.

Key Specifications

Pinout & Package

SOT-23-5 surface-mount package (2.9mm × 1.6mm × 1.1mm), lead-free and RoHS-compliant, optimized for high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX823SEUR+T and TPS3808G12DBVR, the DS1819BR-10+T&R uniquely delivers 3.3V-optimized ±10% trip accuracy, integrated PBRST debouncing, and simultaneous active-high/low reset outputs - making it optimal for new 3V embedded designs requiring full-feature supervision in minimal area.

Availability

DS1819BR-10+T&R is available at Aetrix Electronics and suitable for industrial automation, smart metering, and medical device applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for DS1819BR-10+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 and mixed-signal ICs for industrial, automotive, and communications markets, with emphasis on reliability and integration.

The DS1819BR-10+T&R belongs to the MicroMonitor™ family of supervisory circuits engineered specifically for robust power and watchdog management in 3.3V microprocessor systems operating across extended industrial temperatures.

FAQ

What is the exact VCC trip voltage range for DS1819BR-10+T&R?

The DS1819BR-10+T&R has a guaranteed VCC trip point between 2.85V and 3.00V at 25°C, reflecting its ±10% tolerance specification for 3.0V nominal systems. This range is validated across the full industrial temperature range (–40°C to +85°C) with 5mV hysteresis to prevent chatter near threshold. The DS1819BR-10+T&R uses an internal temperature-compensated reference to maintain accuracy without external calibration.

Does DS1819BR-10+T&R support both watchdog and pushbutton reset functions?

No - the DS1819BR-10+T&R is the 'B' variant and supports watchdog timer functionality via the ST input but does not include the PBRST (pushbutton reset) input. That function is available only on DS1819A and DS1819C variants. The DS1819BR-10+T&R provides RST (active-low) and RST (active-high) outputs, and its ST pin must be toggled every 1.12 seconds to prevent timeout.

Can DS1819BR-10+T&R operate below 3.0V, and what happens to reset output validity?

Yes - the DS1819BR-10+T&R operates with VCC as low as 1.0V, and its RST output remains valid (logic-low or logic-high) down to 1.0V. Below 1.0V, a 100kΩ pull-down resistor from RST to GND maintains valid reset assertion down to 0V VCC, as confirmed in the DS1814/DS1819 datasheet Figure 9. This behavior is intrinsic to the DS1819BR-10+T&R's push-pull output stage design.

Is DS1819BR-10+T&R pin-compatible with MAX823 series devices?

Yes - the DS1819BR-10+T&R is explicitly documented as pin- and function-compatible with the MAX823/24/25 family in the provided datasheet. All five pins (RST, GND, RST, ST, VCC) match the same physical layout and electrical roles. However, note that MAX823 variants are 5V-only, so while mechanical and logical pinout aligns, voltage-range compatibility must be verified per application.

What is the minimum recommended ST input pulse width for reliable watchdog reset on DS1819BR-10+T&R?

The DS1819BR-10+T&R requires a minimum ST input pulse width of 50ns (as specified in AC Electrical Characteristics table), with noise immunity against pulses <100ns. To ensure robust operation, design the ST signal with ≥100ns high/low transitions and ≤1.12s interval between edges. The DS1819BR-10+T&R's internal watchdog timer resets on any ST edge (rising or falling), and failure to meet this timing triggers a 140ms reset pulse on both RST outputs.