Analog Devices Inc./Maxim Integrated DS1814CR-5-U

Overview

DS1814CR-5-U from Maxim Integrated is a 5V microprocessor supervisory circuit that provides power-on reset, watchdog timer, and pushbutton reset functions in a SOT-23-5 package. It monitors VCC with 5% accuracy (trip point 4.50–4.75V), asserts active-low RST for ≥140ms during power-up/failure, and features a 1.12s watchdog timeout with ST strobe input and PBRST pushbutton input.

For engineers reviewing the DS1814CR-5-U datasheet, DS1814CR-5-U pinout, DS1814CR-5-U application, or DS1814CR-5-U equivalent, this device serves as a precision voltage monitor and system supervisor for embedded microcontroller systems requiring reliable power sequencing, fault recovery, and manual reset control under industrial temperature conditions.

Technical Context

The DS1814CR-5-U implements a precision bandgap-based voltage comparator with 10mV hysteresis to detect VCC drop below 4.50V, holding RST active until VCC recovers and remains stable for ≥140ms. Its internal watchdog timer resets on ST input transitions within 1.12s, and its PBRST input debounces external button presses to generate a clean 140ms reset pulse.

This variant belongs to the 'C' version of the DS1814 family, providing both active-low RST (Pin 1) and active-high RST (Pin 3), plus PBRST (Pin 4) - distinguishing it from 'A' (RST + PBRST) and 'B' (RST + RST) variants. All versions operate across -40°C to +85°C and draw ≤15µA quiescent current at 5.5V.

Key Specifications

Pinout & Package

SOT-23-5 surface-mount package (2.9mm × 1.6mm × 1.1mm), thermally enhanced, RoHS-compliant, rated for industrial temperature range.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX823SEUK+T and TPS3808G15DBVR, the DS1814CR-5-U uniquely integrates pushbutton reset, dual-polarity reset outputs, and watchdog functionality in a single SOT-23-5 footprint-reducing BOM count and PCB area where full supervision capability is required.

Availability

DS1814CR-5-U is available at Aetrix Electronics and suitable for industrial PLC controllers, smart metering systems, medical handheld diagnostics, and automotive body control modules requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for DS1814CR-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 computing applications.

The DS1814CR-5-U belongs to the MicroMonitor™ supervisory product line, engineered specifically to replace discrete reset circuits in microcontroller-based systems with integrated voltage monitoring, watchdog, and pushbutton reset-all in ultra-small packages.

FAQ

What is the exact VCC trip point specification for DS1814CR-5-U?

The DS1814CR-5-U has a nominal VCC trip point of 4.63V with ±5% tolerance, meaning it asserts reset when VCC falls below 4.50V (min) and releases reset only after VCC rises above 4.75V (max). This 10mV hysteresis prevents chatter near the threshold and is factory-trimmed using temperature-compensated bandgap reference technology. The DS1814CR-5-U datasheet specifies VCCTP = 4.50V to 4.75V under recommended operating conditions.

Does DS1814CR-5-U support both active-low and active-high reset outputs simultaneously?

Yes, the DS1814CR-5-U is the 'C' variant of the DS1814 family and provides two independent reset outputs: Pin 1 (RST) is active-low, and Pin 3 (RST) is active-high. Both outputs are asserted concurrently during power failure, watchdog timeout, or PBRST activation, enabling direct interface to MCUs or peripherals requiring either polarity without level-shifting components. This dual-output capability is confirmed in the DS1814/DS1819 pin assignment table for 'C' versions.

Can the watchdog function of DS1814CR-5-U be disabled, and how?

Yes, the watchdog function in DS1814CR-5-U can be disabled by leaving the ST (strobe) input unconnected (floating) or tri-stated. When ST is not driven, the internal watchdog timer remains inactive and does not assert reset due to timeout. This behavior is explicitly documented in the DS1814/DS1819 datasheet under "Watchdog Timer" and "WATCHDOG DISABLE CIRCUIT" sections. No external components are required to disable the watchdog in DS1814CR-5-U.

What is the minimum VCC level at which DS1814CR-5-U guarantees valid RST output?

The DS1814CR-5-U guarantees valid RST output down to VCC = 1.0V due to its push-pull output stage. Below 1.0V, a pull-down resistor (e.g., 100kΩ from RST to GND) extends valid reset assertion down to 0V VCC - a feature critical for fail-safe shutdown in battery-depleted or brownout scenarios. This capability is specified in the "OUTPUT VALID CONDITIONS" section of the DS1814/DS1819 datasheet and verified across -40°C to +85°C.

Is DS1814CR-5-U pin-compatible with MAX823-series supervisors?

Yes, DS1814CR-5-U is pin- and function-compatible with the MAX823/824/825 family per the official DS1814/DS1819 datasheet, which states "Pin- and function-compatible with the MAX823/24/25 products." This includes identical SOT-23-5 pinout (RST, GND, PBRST/ST/RST, ST/PBRST/RST, VCC depending on variant), matching reset timing, and compatible voltage thresholds. However, DS1814CR-5-U adds PBRST and dual-RST not present in base MAX823, so full functional compatibility requires verifying variant mapping.