Analog Devices Inc./Maxim Integrated DS1817R-5-U

Overview

DS1817R-5-U from Maxim Integrated (now Analog Devices) is a precision voltage-monitoring supervisory IC that provides active-high reset signaling for microprocessors during power failure or brownout events. It features a 3.0V trip point with ±5% tolerance, 150ms reset pulse width, push-pull output, and operates from -40°C to +85°C in SOT-23 package - used in embedded systems requiring reliable power-on reset and supply monitoring.

For engineers reviewing the DS1817R-5-U datasheet, DS1817R-5-U pinout, DS1817R-5-U application, or DS1817R-5-U equivalent, key selection criteria include VCC trip accuracy (2.98V–3.15V), guaranteed 100–250ms reset assertion time, push-pull output drive capability (350µA VOH, 10mA IOL), low 28–35µA operating current, and compatibility with 3.0V/3.3V systems.

Technical Context

The DS1817R-5-U integrates a temperature-compensated bandgap reference and comparator to detect VCC deviations against a fixed 3.0V threshold (±5%). Its internal timing circuit ensures reset remains asserted for ≥100ms and ≤250ms after VCC returns to tolerance, satisfying processor stabilization requirements.

It delivers a push-pull active-high RST signal without external pull-up, supports VCC from 1.2V to 5.5V, and maintains functional integrity across full industrial temperature range (-40°C to +85°C) with <35µA quiescent current - enabling direct integration into low-power embedded control paths.

Key Specifications

Pinout & Package

SOT-23-3 surface-mount package (2.9mm × 1.6mm × 1.1mm), RoHS-compliant, tape-and-reel delivery.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage-monitoring reset applications.

Compared with DS1817R-5-U, TPS3808G15DBVR targets lower-voltage domains and requires external biasing, while MAX6326UT29D3+T offers superior trip accuracy and tighter reset timing at a slightly higher trip voltage - both serve distinct design constraints rather than drop-in replacement roles.

Availability

DS1817R-5-U is available at Aetrix Electronics and suitable for industrial control, medical handheld devices, automotive infotainment modules, and smart energy meters requiring stable component supply and long-term manufacturability.

Supply support for DS1817R-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 high-performance analog and mixed-signal semiconductor solutions for industrial, communications, and consumer applications.

The DS1817R-5-U belongs to the EconoReset™ family of supervisory ICs engineered specifically for cost-sensitive, space-constrained embedded systems needing reliable power-on reset and brownout protection without external components.

FAQ

What is the exact VCC trip voltage range for DS1817R-5-U?

The DS1817R-5-U has a guaranteed VCC trip point between 2.98V and 3.15V at -40°C to +85°C, corresponding to a nominal 3.0V threshold with ±5% tolerance. This range is validated per the device's DC electrical characteristics table and applies directly to the DS1817R-5-U variant marked for 5% tolerance - not the -10 or -20 versions.

Does DS1817R-5-U require an external pull-up resistor on the RST pin?

No, DS1817R-5-U does not require an external pull-up resistor because it features a push-pull active-high output stage. The RST pin drives high to VCC–0.1V and low to <0.4V, enabling direct connection to microcontroller reset inputs without additional components - a key design advantage over open-drain alternatives.

What is the minimum and maximum reset pulse width of DS1817R-5-U?

The DS1817R-5-U asserts reset for a guaranteed minimum of 100ms and maximum of 250ms after VCC returns to tolerance. Typical duration is 150ms, as specified in the AC Electrical Characteristics table. This timing ensures compatibility with common microprocessor reset setup requirements across ARM, PIC, and legacy 8-bit architectures.

Can DS1817R-5-U operate with supply voltages below 3.0V?

Yes, DS1817R-5-U operates with VCC from 1.2V to 5.5V per its Recommended DC Operating Conditions. However, the 3.0V ±5% trip point remains fixed relative to the applied VCC rail - meaning accurate monitoring of 3.0V systems requires VCC ≥3.0V. Below that, the device remains functional but cannot assert reset based on its specified threshold.

Is DS1817R-5-U pin-compatible with other DS1817 variants like DS1817R-10-U?

Yes, DS1817R-5-U is pin-compatible with DS1817R-10-U and DS1817R-20-U - all share identical SOT-23-3 pinout (RST/VCC/GND), same package dimensions, and identical thermal and electrical interface behavior. Only the VCC trip point differs: 2.98–3.15V (-5%), 2.80–2.97V (-10%), or 2.47–2.64V (-20%).