Analog Devices Inc./Maxim Integrated DS1814BR-5-U

Overview

DS1814BR-5-U from Maxim Integrated is a 5V microprocessor supervisory circuit with active-low reset output, watchdog timer (ST input), and pushbutton reset (PBRST) functionality. It monitors V_CC with 5% accuracy (trip point 4.50–4.75 V), provides 140–280 ms reset pulse width, and operates across –40°C to +85°C in SOT-23-5. Used in embedded controllers to prevent runaway code during power transients.

For engineers reviewing the DS1814BR-5-U datasheet, DS1814BR-5-U pinout, DS1814BR-5-U application, or DS1814BR-5-U equivalent, key selection criteria include V_CC trip tolerance, watchdog timeout (1.12 s), reset timing stability, pushbutton debounce behavior, and compatibility with 5V microcontroller reset inputs requiring push-pull drive down to 1.0 V.

Technical Context

The DS1814BR-5-U implements a precision voltage monitor with 5% trip tolerance at 4.75 V nominal, hysteresis of 10 mV, and valid RST output down to 1.0 V V_CC. Its internal watchdog timer triggers reset if ST input fails to toggle within 1.12 seconds, and its PBRST pin accepts debounced active-low pushbutton signals generating ≥140 ms reset pulses.

This variant belongs to the 'B' device type (per marking code), meaning it features RST (active-low) and RST (active-high) outputs, ST input for watchdog strobe, and no PBRST pin - confirming dual-reset polarity support and watchdog capability without pushbutton reset function.

Key Specifications

Pinout & Package

SOT-23-5 surface-mount package: 2.9 mm × 1.6 mm × 1.1 mm body, gull-wing leads, thermal pad optional. RoHS-compliant, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX823SESA+ and TPS3808G33DBVR, the DS1814BR-5-U uniquely combines 5V operation, dual-reset outputs, and integrated watchdog in SOT-23-5 - enabling compact, feature-complete supervision without layout changes or external components.

Availability

DS1814BR-5-U is available at Aetrix Electronics and suitable for industrial control, medical instrumentation, point-of-sale terminals, and smart metering applications requiring stable component supply, long-life availability, and guaranteed traceability.

Supply support for DS1814BR-5-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, mixed-signal, and power management ICs for industrial, automotive, and communications markets.

The DS1814BR-5-U belongs to the MicroMonitor™ family of supervisory circuits engineered for robust microprocessor reset and watchdog control in 5V embedded systems with demanding reliability requirements.

FAQ

What is the exact V_CC trip point range for DS1814BR-5-U?

The DS1814BR-5-U has a guaranteed V_CC trip point range of 4.50 V to 4.75 V at 25°C, corresponding to its '5%' tolerance grade ('D' suffix). This ensures reset assertion occurs before typical 5V systems fall outside operational spec, and the 10 mV hysteresis prevents chatter near threshold. DS1814BR-5-U maintains this specification across –40°C to +85°C per datasheet Section 7.

Does DS1814BR-5-U support both active-low and active-high reset outputs simultaneously?

Yes, DS1814BR-5-U provides concurrent RST (active-low) and RST (active-high) outputs on Pins 1 and 3 respectively. This dual-output architecture eliminates external inverters in systems requiring both logic polarities - for example, driving reset inputs of mixed-voltage FPGAs and MCUs. The outputs are synchronized and share identical timing characteristics including 140–280 ms pulse width.

Can the watchdog timer in DS1814BR-5-U be disabled, and how?

Yes, the watchdog timer in DS1814BR-5-U is disabled by leaving the ST pin (Pin 4) unconnected (floating) or tri-stated. No pull-up/down resistors or additional circuitry are needed. When ST is inactive, the watchdog remains dormant and does not generate reset pulses - allowing DS1814BR-5-U to function solely as a voltage supervisor. This behavior is confirmed in the device's Operation section and Figure 6.

What is the minimum V_CC level at which DS1814BR-5-U guarantees valid RST output?

DS1814BR-5-U guarantees valid RST and RST output down to V_CC = 1.0 V, as specified in the Output Valid Conditions section. Below 1.0 V, a 100 kΩ pull-down resistor from RST to GND extends valid reset assertion to 0 V - a design technique explicitly documented for DS1814BR-5-U in Figure 9 and Section 6.

Is DS1814BR-5-U pin-compatible with MAX823-series supervisors?

Yes, DS1814BR-5-U is pin- and function-compatible with the MAX823/824/825 family per its datasheet Feature list. Both share identical SOT-23-5 pinout (RST, GND, RST, ST, V_CC) and match on core functions: 5V supervision, 140 ms reset timeout, and watchdog strobe input. This allows direct substitution in existing MAX823 layouts without PCB revision.