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

Overview

DS1819BR-10/TR from Maxim Integrated is a 3.3V microprocessor supervisory circuit with voltage monitoring, watchdog timer, and pushbutton reset functions. It provides active-low reset output, monitors VCC at 2.85V to 3.00V (±10%), delivers 140ms minimum reset pulse width, and operates across -40°C to +85°C in SOT-23-5 package - used in embedded industrial controllers for reliable power-up sequencing and fault recovery.

For engineers reviewing the DS1819BR-10/TR datasheet, DS1819BR-10/TR pinout, DS1819BR-10/TR application, or DS1819BR-10/TR equivalent, key selection criteria include its 3V supply monitoring accuracy, integrated watchdog timeout of 1.12s, pushbutton debounce capability, SOT-23-5 footprint compatibility with MAX823/24/25, and industrial temperature operation without external components.

Technical Context

The DS1819BR-10/TR implements a precision bandgap reference and comparator for VCC supervision, generating reset when supply falls below 2.85V (min) with 5mV hysteresis. Its internal watchdog timer triggers reset if the ST strobe input fails to toggle within 1.12 seconds, and it debounces PBRST inputs to produce a clean 140ms reset pulse on release.

This device integrates three critical supervisory functions - power-fail detection, software execution monitoring via watchdog, and manual override - into a single 5-pin SOT-23 package. The RST output uses a push-pull driver capable of valid logic down to 1.0V VCC, and supports resistor pull-down for 0V-valid reset assertion during full power-down.

Key Specifications

Pinout & Package

SOT-23-5 surface-mount package with 0.95mm pitch, 2.9mm × 1.6mm footprint, and thermal pad option per drawing 21-0057F.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS1819BR-10/TR, MAX823SEUR+T serves 5V systems only and omits pushbutton support, while TPS3808G12DBVR offers flexibility at the cost of integration - DS1819BR-10/TR uniquely combines 3V precision monitoring, hardware-debounced PBRST, and 1.12s watchdog in one SOT-23-5 device.

Availability

DS1819BR-10/TR is available at Aetrix Electronics and suitable for industrial PLC controllers, smart energy meters, medical handheld diagnostics, and factory automation sensor nodes requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for DS1819BR-10/TR 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, mixed-signal, and power management ICs for industrial, automotive, communications, and computing applications.

The DS1819BR-10/TR belongs to Maxim's MicroMonitor™ family of supervisory circuits, engineered specifically to replace discrete reset solutions in space-constrained, reliability-critical embedded systems operating at 3.3V.

FAQ

What is the exact VCC trip point range for DS1819BR-10/TR?

The DS1819BR-10/TR has a guaranteed VCC trip point range of 2.85V (minimum) to 3.00V (maximum), corresponding to its ±10% tolerance specification for 3.3V systems. This is confirmed in the DC Electrical Characteristics table under "VCC Trip Point DS1819-10" and applies across the full -40°C to +85°C operating temperature range. The device asserts RST when VCC falls below this window and holds it active for ≥140ms after VCC recovers.

Does DS1819BR-10/TR support both watchdog and pushbutton reset simultaneously?

Yes, DS1819BR-10/TR supports both functions concurrently. As a 'B' variant per Maxim's naming convention ('19B' = DS1819B), it includes ST (strobe input) for watchdog operation and PBRST (pin 3) for pushbutton reset - both active simultaneously. The device will assert RST on any condition: VCC dropout, ST timeout, or PBRST release, with no conflict between paths.

Is DS1819BR-10/TR pin-compatible with MAX823 series devices?

Yes, DS1819BR-10/TR is pin- and function-compatible with the MAX823/24/25 family as explicitly stated in the Features section of the datasheet. All five pins map identically: RST (1), GND (2), PBRST (3), ST (4), VCC (5). No PCB layout changes are needed when substituting DS1819BR-10/TR into existing MAX823 designs targeting 3.3V operation.

What is the minimum VCC required for DS1819BR-10/TR to maintain valid RST output?

The DS1819BR-10/TR maintains valid RST logic levels down to 1.0V VCC using its internal push-pull output stage. For full 0V-valid reset assertion - critical in deep brownout scenarios - an external ~100kΩ pull-down resistor from RST to GND is recommended, as documented in Figure 9 and the "OUTPUT VALID CONDITIONS" section.

How does the watchdog timer in DS1819BR-10/TR behave during power-up?

The DS1819BR-10/TR watchdog timer begins timing only after RST becomes inactive (i.e., after the initial 140ms power-up reset pulse ends). During power-up, the device prioritizes VCC monitoring and holds RST active until VCC stabilizes above 3.00V and remains there for ≥140ms - the watchdog remains disabled until that point, preventing spurious timeouts during startup.