Analog Devices Inc./Maxim Integrated DS1819BR-10-U

Overview

DS1819BR-10-U from Maxim Integrated is a 3.3V microprocessor supervisory circuit with watchdog timer and pushbutton reset functionality in SOT-23-5 package. It monitors VCC (trip point 2.85–3.00 V), provides 140–280 ms active-low reset pulse, features 1.12 s watchdog timeout, operates from −40°C to +85°C, and supports power-up/power-down reset assertion down to 0 V VCC - used in embedded controllers for industrial sensor nodes requiring reliable brownout and software fault recovery.

For engineers reviewing the DS1819BR-10-U datasheet, DS1819BR-10-U pinout, DS1819BR-10-U application, or DS1819BR-10-U equivalent, key selection criteria include its 10% VCC threshold tolerance, dual reset outputs (RST and RST), watchdog strobe input (ST), pushbutton reset input (PBRST), and compatibility with MAX823/24/25 functional equivalents in space-constrained 3.3V systems.

Technical Context

The DS1819BR-10-U implements a precision bandgap-based voltage monitor with 5 mV hysteresis and a 1.12 s watchdog timer that resets on ST input transitions. Its dual-reset architecture delivers both active-low (RST) and active-high (RST) signals simultaneously, enabling direct interface to diverse microcontroller reset inputs without external level-shifting.

It integrates internal debouncing for PBRST (500 ns delay, <100 ns noise immunity), push-pull RST output valid down to 0 V VCC (with optional 100 kΩ pull-down), and operates across full 1.0–5.5 V supply range - supporting robust power sequencing and fail-safe recovery in battery-backed or low-voltage industrial control systems.

Key Specifications

Pinout & Package

SOT-23-5 surface-mount package (2.9 mm × 1.6 mm × 1.1 mm), RoHS-compliant, thermal pad not present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX823SEUK+T and TPS3808G12DBVR, the DS1819BR-10-U uniquely delivers dual-reset outputs, integrated pushbutton support, and guaranteed 0 V VCC reset validity - making it optimal for compact 3.3 V systems needing deterministic recovery under brownout, software fault, and manual reset conditions.

Availability

DS1819BR-10-U is available at Aetrix Electronics and suitable for industrial automation, smart metering, medical sensor hubs, and automotive body electronics requiring stable component supply across extended temperature and long product lifecycles.

Supply support for DS1819BR-10-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 and mixed-signal ICs for industrial, automotive, and communications applications - emphasizing reliability, low power, and integration.

The DS1819BR-10-U belongs to the MicroMonitor™ supervisory family, engineered specifically for fault-tolerant microprocessor systems requiring simultaneous power monitoring, watchdog supervision, and manual reset capability in minimal footprint.

FAQ

What is the exact VCC trip point tolerance for DS1819BR-10-U?

The DS1819BR-10-U has a guaranteed VCC trip point of 2.85 V to 3.00 V, corresponding to ±10% tolerance around the nominal 3.0 V supply. This is confirmed in the DC Electrical Characteristics table (page 6) and marked by the "B" suffix in the device code per the Part Marking Codes section (page 8). The DS1819BR-10-U maintains this specification across −40°C to +85°C.

Does DS1819BR-10-U provide both active-low and active-high reset outputs?

Yes, the DS1819BR-10-U provides two independent reset outputs: Pin 1 (RST) is active-low, and Pin 3 (RST) is active-high. This dual-output configuration is explicitly defined in the PIN ASSIGNMENT table for DS181xB variants (page 1), and the DS1819BR-10-U is a 'B' version per its marking code ('19B'). Both outputs assert simultaneously during power failure, watchdog timeout, or PBRST activation.

Can the watchdog timer in DS1819BR-10-U be disabled, and how?

Yes, the watchdog timer in DS1819BR-10-U can be disabled by leaving the ST input (Pin 4) floating or tri-stated - no external components required. As stated in the OPERATION section (page 2), "The watchdog can be disabled by floating (or tri-stating) the ST input." This behavior is inherent to the internal circuit design and does not require configuration bits or external pull resistors.

What is the minimum VCC required for DS1819BR-10-U to generate a valid reset signal?

The DS1819BR-10-U's RST output remains logic-valid down to 0 V VCC when a 100 kΩ pull-down resistor is connected from RST to GND (per Figure 9, page 6). Without the pull-down, the push-pull RST output is guaranteed valid down to 1.0 V VCC. This 0 V capability ensures deterministic reset assertion during complete power collapse - a key differentiator versus most supervisory ICs.

Is DS1819BR-10-U pin-compatible with MAX823 series devices?

Yes, the DS1819BR-10-U is pin- and function-compatible with the MAX823/24/25 products, as explicitly stated in the FEATURES section (page 1). This includes identical SOT-23-5 pinout (RST, GND, RST, ST, VCC), matching reset timing, and equivalent watchdog and power-monitoring behavior - enabling drop-in replacement in existing 3.3 V designs originally using MAX823 variants.