Analog Devices Inc./Maxim Integrated DS1814BR-5+T&R

Overview

DS1814BR-5+T&R from Maxim Integrated is a 5V microprocessor supervisory circuit in SOT-23-5 package, providing precision power monitoring (4.50–4.75 V trip), watchdog timer (1.12 s timeout), and pushbutton reset control with 140 ms minimum active-reset pulse width. It halts and restarts out-of-control microprocessors during power transients or software lockups in embedded industrial controllers.

For engineers reviewing the DS1814BR-5+T&R datasheet, DS1814BR-5+T&R pinout, DS1814BR-5+T&R application, or DS1814BR-5+T&R equivalent, key selection criteria include VCC trip accuracy (±5%), guaranteed 140 ms reset hold time, watchdog strobe timing compatibility, and SOT-23-5 footprint suitability for space-constrained PCB layouts.

Technical Context

The DS1814BR-5+T&R implements a precision voltage monitor with temperature-compensated reference and comparator, generating an active-low RST output when VCC drops below 4.50 V (min) and holding it active for ≥140 ms after recovery. Its internal watchdog timer resets on ST input transitions occurring at ≤1.12 s intervals, with timeout disabling possible via floating ST.

This variant is the 'B' type (per marking code 14B), meaning it provides both active-low RST (Pin 1) and active-high RST (Pin 3), supports watchdog function (ST on Pin 4), but excludes pushbutton reset (no PBRST pin). It operates across -40°C to +85°C and draws only 10–15 µA typical supply current.

Key Specifications

Pinout & Package

SOT-23-5 surface-mount package with 1.6 mm × 2.9 mm footprint, 0.95 mm 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 TPS3808G15DBVR, the DS1814BR-5+T&R uniquely delivers pin-compatible dual-reset outputs (RST/RST) and guaranteed 140 ms hold time in a 5-pin SOT-23, simplifying design for systems needing both logic polarities without board rework.

Availability

DS1814BR-5+T&R is available at Aetrix Electronics and suitable for industrial automation, medical device, smart metering, and automotive body electronics requiring stable component supply and long-term lifecycle support.

Supply support for DS1814BR-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 precision analog, mixed-signal, and power management ICs for demanding industrial, medical, and communications applications.

The DS1814BR-5+T&R belongs to the MicroMonitor family-engineered specifically for robust microprocessor supervision in harsh environments where voltage accuracy, watchdog reliability, and dual-reset interface are critical.

FAQ

What is the exact VCC trip point specification for DS1814BR-5+T&R?

The DS1814BR-5+T&R has a nominal VCC trip point of 4.75 V with a tolerance of ±5%, resulting in a guaranteed range of 4.50 V to 4.75 V. This value is specified under recommended operating conditions (-40°C to +85°C, VCC = 1.2 V to 5.5 V) and reflects the voltage at which the internal comparator triggers the RST and RST outputs. The DS1814BR-5+T&R uses a temperature-compensated reference to maintain this accuracy across its full industrial temperature range.

Does DS1814BR-5+T&R support both watchdog and pushbutton reset functions?

No, the DS1814BR-5+T&R is the 'B' variant (per marking code 14B), which supports watchdog functionality via the ST pin (Pin 4) but does not include pushbutton reset capability-PBRST is absent. Only DS1814A and DS1814C variants provide PBRST. The DS1814BR-5+T&R delivers dual reset outputs (RST and RST) and watchdog timeout detection with 1.12 s default period, making it ideal for systems requiring supervised software execution without manual reset buttons.

Can DS1814BR-5+T&R operate reliably below 2.0 V VCC?

Yes-the DS1814BR-5+T&R maintains valid RST output down to 1.0 V VCC due to its push-pull driver architecture. Below 1.0 V, a 100 kΩ pull-down resistor from RST to GND extends valid reset assertion to 0 V, ensuring deterministic behavior during deep brownout or complete power collapse. This feature is explicitly confirmed in the datasheet's "OUTPUT VALID CONDITIONS" section and verified across the full -40°C to +85°C range, distinguishing DS1814BR-5+T&R from many competitors that lose output validity below 2.0 V.

Is DS1814BR-5+T&R pin-compatible with MAX823 series devices?

Yes, the DS1814BR-5+T&R is explicitly documented as pin- and function-compatible with the MAX823/24/25 family. It shares identical SOT-23-5 pinout (RST, GND, RST, ST, VCC), same 5 V operation, and overlapping trip thresholds. However, unlike some MAX823 variants, DS1814BR-5+T&R provides both active-low and active-high reset outputs natively-eliminating the need for external inversion in mixed-logic designs while maintaining drop-in replacement capability for most existing MAX823-based layouts.

What is the maximum watchdog timeout deviation over temperature for DS1814BR-5+T&R?

The DS1814BR-5+T&R watchdog timeout is specified as 1.12–2.40 s over the full -40°C to +85°C operating range, with 1.12 s being the minimum guaranteed timeout. This 2.40 s upper limit represents worst-case variation including process, voltage, and temperature effects. The datasheet confirms this range under "AC ELECTRICAL CHARACTERISTICS" and notes that timeout stability is maintained without external components-making DS1814BR-5+T&R suitable for safety-critical applications where bounded fault-detection latency is required.