Analog Devices Inc./Maxim Integrated DS1814AR-5+T&R

Overview

DS1814AR-5+T&R from Maxim Integrated is a 5V microprocessor supervisory circuit with power monitoring, watchdog timer, and pushbutton reset functions. It provides active-low reset output (RST), monitors VCC trip point at 4.50–4.75 V (±5%), delivers 140–280 ms reset pulse width, and operates across –40°C to +85°C in SOT-23-5 package for embedded microcontroller power integrity.

For engineers reviewing the DS1814AR-5+T&R datasheet, DS1814AR-5+T&R pinout, DS1814AR-5+T&R application, or DS1814AR-5+T&R equivalent, key selection criteria include VCC trip accuracy (±5%), 1.12 s watchdog timeout, push-pull RST output valid down to 1.0 V VCC, and compatibility with MAX823/24/25 for drop-in replacement in industrial control and instrumentation designs.

Technical Context

The DS1814AR-5+T&R implements a precision voltage monitor with 4.50–4.75 V trip threshold and 10 mV hysteresis, ensuring reliable power-fail detection during brownout conditions. Its internal watchdog timer triggers reset if the ST strobe input fails to toggle within 1.12 s, and its pushbutton reset input (PBRST) is debounced to generate ≥140 ms active-low reset pulses on release.

This 'A' variant integrates three core functions: power supply supervision (VCC monitoring), software execution monitoring (watchdog via ST), and external override (PBRST). All reset outputs are push-pull, maintaining logic validity down to 1.0 V VCC, and the device draws only 10–15 µA quiescent current over full temperature range.

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 TPS3808G50DBVR, the DS1814AR-5+T&R uniquely integrates power monitoring, watchdog timer, and debounced pushbutton reset in one SOT-23-5 package-reducing component count, PCB area, and qualification effort for compact industrial and medical systems requiring all three functions.

Availability

DS1814AR-5+T&R is available at Aetrix Electronics and suitable for industrial PLC control, medical diagnostic equipment, and automotive body control modules requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for DS1814AR-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 high-performance analog, mixed-signal, and power management ICs for industrial, medical, and communications applications.

The DS1814AR-5+T&R belongs to the MicroMonitor™ family of supervisory circuits, engineered specifically to replace discrete reset generators and watchdog timers in resource-constrained microcontroller systems.

FAQ

What is the exact VCC trip point specification for DS1814AR-5+T&R?

The DS1814AR-5+T&R has a guaranteed VCC trip point of 4.50 V minimum and 4.75 V maximum, corresponding to ±5% tolerance around a nominal 4.63 V threshold. This specification applies across the full operating temperature range (–40°C to +85°C) and ensures reliable reset assertion before the microprocessor's minimum functional supply voltage is violated. The DS1814AR-5+T&R uses an internal temperature-compensated reference to maintain this accuracy without external components.

Does DS1814AR-5+T&R support both watchdog and pushbutton reset simultaneously?

Yes, the DS1814AR-5+T&R ('A' variant) supports both functions concurrently: the ST pin enables watchdog monitoring with 1.12 s timeout, and the PBRST pin accepts active-low pushbutton signals with internal debounce and ≥140 ms reset pulse generation. These functions operate independently-the watchdog can be disabled by floating ST, while PBRST remains fully functional. This dual capability is confirmed in the device's pin assignment table and functional description for DS181xA variants.

Can DS1814AR-5+T&R drive a microcontroller reset input directly without external components?

Yes, the DS1814AR-5+T&R features a push-pull RST output capable of sinking up to 6 mA and sourcing 350 µA, eliminating the need for an external pull-up resistor. Its output remains valid down to 1.0 V VCC, ensuring deterministic logic levels during brownout. The DS1814AR-5+T&R datasheet explicitly states that the RST pin drives "active-low reset" directly into standard microcontroller reset inputs, and no external passive components are required for basic operation.

Is DS1814AR-5+T&R pin-compatible with MAX823-series devices?

Yes, the DS1814AR-5+T&R is pin- and function-compatible with the MAX823/24/25 family per its official datasheet feature list. All share identical SOT-23-5 pinout (RST, GND, PBRST, ST, VCC), same reset timing, and overlapping VCC trip ranges. This compatibility allows direct substitution in existing designs using MAX823SESA+ or MAX824TESA+, provided the target application requires the 'A' variant's combined watchdog and pushbutton functionality.

What is the minimum VCC required for DS1814AR-5+T&R to assert a valid reset signal?

The DS1814AR-5+T&R maintains a valid active-low RST output down to 1.0 V VCC, as specified in the "OUTPUT VALID CONDITIONS" section of its datasheet. Below 1.0 V, a 100 kΩ pull-down resistor from RST to GND extends validity to 0 V VCC. This behavior is intrinsic to the DS1814AR-5+T&R's push-pull output stage design and is verified across temperature and process corners-enabling safe shutdown sequencing in systems with abrupt power loss.