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 (±10% VCC trip at 2.85–3.00 V), watchdog timer (1.12 s 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 power-up sequencing and fail-safe recovery.

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%), 140 ms 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 bandgap-based voltage monitor with 5 mV hysteresis, ensuring stable reset assertion/deassertion during VCC brownout. Its internal watchdog timer requires ST input toggling every ≤1.12 s to prevent timeout-induced reset activation.

It features dual reset outputs: RST (active-low) on Pin 1 and RST (active-high) on Pin 3 - confirmed for 'B' variant per device matrix - enabling direct interface with both active-low and active-high reset logic in microcontrollers. The PBRST pin is not present in 'B' versions, distinguishing it from 'A' and 'C' variants.

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 automated placement and reflow soldering in high-volume production.

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 delivers fixed ±10% 3.3 V supervision with built-in watchdog and dual-reset outputs in a drop-in SOT-23-5 package-reducing BOM count and layout complexity for 3 V embedded systems.

Availability

DS1819BR-10/T&R is available at Aetrix Electronics and suitable for industrial automation, smart metering, medical handhelds, and automotive body electronics requiring stable component supply across extended product lifecycles.

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, mixed-signal, and power management ICs for industrial, automotive, and communications applications.

The DS1819BR-10/T&R belongs to the MicroMonitor™ family of supervisory circuits, engineered specifically to replace discrete reset generators and watchdog timers in 3.3 V microprocessor systems with guaranteed timing and voltage accuracy.

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 of 2.85 V to 3.00 V at 25 °C, corresponding to ±10% tolerance around a nominal 3.0 V supply. This range is validated across the full −40 °C to +85 °C operating temperature range and includes 5 mV hysteresis to prevent chatter near the threshold. The DS1819BR-10/T&R uses an internal temperature-compensated bandgap reference to maintain accuracy without external calibration.

Does DS1819BR-10/T&R support both active-low and active-high reset outputs?

Yes, the DS1819BR-10/T&R provides two independent reset outputs: Pin 1 (RST) is active-low, and Pin 3 (RST) is active-high. This dual-output capability allows direct interfacing with microcontrollers that require either polarity without external inverters or level translators. Both outputs are synchronized and assert simultaneously during power faults, watchdog timeouts, or power-up sequences. The DS1819BR-10/T&R 'B' variant confirms this configuration per the official pin assignment table.

Can the watchdog function of DS1819BR-10/T&R be disabled?

Yes, the watchdog timer in DS1819BR-10/T&R is disabled by leaving the ST (strobe) input floating or tri-stated. No external pull-up or pull-down is required. When ST is inactive, the watchdog remains dormant and does not generate reset pulses. This behavior is explicitly documented in the operation section and verified in Figures 4 and 6 of the official datasheet. The DS1819BR-10/T&R retains full power-monitoring functionality even with watchdog disabled.

What is the minimum reset pulse width guaranteed by DS1819BR-10/T&R?

The DS1819BR-10/T&R guarantees a minimum reset pulse width of 140 ms after VCC returns to a valid level, after a pushbutton release, or following watchdog timeout. This duration is specified across temperature and supply voltage ranges and ensures sufficient time for microcontroller core, PLLs, and peripherals to stabilize before release. The DS1819BR-10/T&R achieves this using an internal RC timing circuit, eliminating reliance on external capacitors.

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

Yes, the DS1819BR-10/T&R is pin- and function-compatible with the MAX823/24/25 family in SOT-23-5 package, including identical pin assignments for RST, GND, RST, ST, and VCC. This compatibility enables drop-in replacement in existing designs targeting 3.3 V operation, provided the original design used a 'B' variant of the MAX823 series. The DS1819BR-10/T&R maintains identical timing, drive strength, and electrical characteristics required for seamless integration.