Analog Devices Inc./Maxim Integrated DS1814CR-5/T&R

Overview

DS1814CR-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 hangs in embedded industrial controllers.

For engineers reviewing the DS1814CR-5/T&R datasheet, DS1814CR-5/T&R pinout, DS1814CR-5/T&R application, or DS1814CR-5/T&R equivalent, key selection criteria include VCC trip accuracy (±5%), watchdog strobe timing compliance, pushbutton debounce behavior, and compatibility with 5V microcontroller reset logic requiring active-low RST and active-high RST outputs.

Technical Context

The DS1814CR-5/T&R implements a dual-reset architecture: Pin 1 delivers active-low RST, Pin 3 delivers active-high RST - both asserted for ≥140 ms after power-up, power-down, or pushbutton release. Its internal comparator uses a temperature-compensated reference to detect VCC falling below 4.50 V (min) with 10 mV hysteresis, ensuring reliable brownout detection across -40°C to +85°C.

The device integrates three independent supervision functions: (1) power monitor with 140 ms reset hold time post-recovery; (2) watchdog timer triggered by ST (Pin 4) transitions every ≤1.12 s; (3) PBRST (Pin 3 on 'A'/'C' variants) with hardware debouncing and 500 ns propagation delay from stable low to RST assertion. Watchdog disable is achieved by floating ST.

Key Specifications

Pinout & Package

SOT-23-5 surface-mount package (2.9 mm × 1.6 mm × 1.1 mm), lead-free and RoHS-compliant, optimized for space-constrained PCB layouts in industrial and automotive control modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX823SESA+ and TPS3808G15DBVR, the DS1814CR-5/T&R uniquely integrates dual-reset outputs, hardware-debounced pushbutton input, and configurable watchdog in one SOT-23-5 package-reducing component count and PCB area while enabling robust fail-safe behavior in resource-constrained 5V systems.

Availability

DS1814CR-5/T&R is available at Aetrix Electronics and suitable for industrial PLC controllers, smart energy meters, automotive body control modules, and medical infusion pump controllers requiring stable component supply with guaranteed long-term availability.

Supply support for DS1814CR-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 industrial, automotive, and computing applications.

The DS1814CR-5/T&R belongs to Maxim's MicroMonitor family, engineered specifically for fail-safe microprocessor supervision in harsh environments where deterministic reset timing, noise immunity, and multi-function integration are critical.

FAQ

What is the exact VCC trip voltage range for DS1814CR-5/T&R?

The DS1814CR-5/T&R has a guaranteed VCC trip point of 4.50 V (minimum) to 4.75 V (typical), with ±5% tolerance as indicated by the "-5" suffix. This range ensures reliable detection of 5V supply brownout before microcontroller operation becomes unstable, and is validated across the full -40°C to +85°C operating temperature range. The DS1814CR-5/T&R uses an internal temperature-compensated reference to maintain this accuracy without external calibration.

Does DS1814CR-5/T&R provide both active-low and active-high reset outputs?

Yes, the DS1814CR-5/T&R provides two independent reset outputs: Pin 1 (RST) is active-low, and Pin 3 (RST) is active-high - both asserted simultaneously during power failure, watchdog timeout, or pushbutton event. This dual-output capability eliminates the need for external inverters in systems using mixed logic families, and is confirmed in the device's pin assignment table for the 'C' variant. The DS1814CR-5/T&R delivers these signals with guaranteed 140 ms minimum pulse width.

How does the watchdog function operate on DS1814CR-5/T&R, and can it be disabled?

The DS1814CR-5/T&R watchdog timer requires a transition on the ST pin (Pin 4) at least every 1.12 seconds to prevent timeout. If no transition occurs, it asserts RST and RST for 140 ms. The watchdog is disabled by leaving ST floating (high-impedance), as explicitly stated in the datasheet's Operation section. This behavior is verified for the 'C' variant, which supports both PBRST and ST functions. No external components are needed for disable functionality.

What is the purpose of the PBRST pin on DS1814CR-5/T&R, and how is it used?

The PBRST pin (Pin 3) on DS1814CR-5/T&R is an active-low pushbutton reset input with integrated hardware debouncing and timing. When the connected pushbutton is released from low, the DS1814CR-5/T&R generates a clean 140 ms minimum reset pulse on both RST outputs. Internal pull-up (50 kΩ typical) eliminates external resistors, and noise immunity rejects pulses <100 ns. This feature is specific to 'A' and 'C' variants, and the DS1814CR-5/T&R is confirmed as a 'C' variant per its marking code.

Is DS1814CR-5/T&R compatible with 3.3V microcontrollers?

No, the DS1814CR-5/T&R is a 5V-specific supervisory device with a 4.50–4.75 V trip point and absolute maximum VCC rating of 7.0 V. It is not designed for 3.3V systems. For 3.3V applications, the DS1819 series (e.g., DS1819R-5) is specified with 2.85–3.15 V trip points. Using DS1814CR-5/T&R with 3.3V logic may result in undetected brownout or improper reset assertion, as confirmed by the Recommended Operating Conditions table in the datasheet.