Analog Devices Inc./Maxim Integrated DS1817R-5+T&R

Overview

DS1817R-5+T&R 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 (±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+T&R datasheet, DS1817R-5+T&R pinout, DS1817R-5+T&R application, or DS1817R-5+T&R equivalent, key selection criteria include VCC trip accuracy (2.98V–3.15V), guaranteed 100–250ms reset assertion time, push-pull drive capability (350µA high-level sink/source), low 28–35µA operating current, and compatibility with 3.0V/3.3V systems.

Technical Context

The DS1817R-5+T&R integrates a temperature-compensated bandgap reference and comparator to detect VCC deviations against a fixed 3.0V threshold. Its internal timing circuit ensures reset remains asserted for ≥100ms after VCC returns to tolerance, with typical 150ms duration and up to 250ms maximum.

It delivers a CMOS-compatible push-pull RST output capable of sourcing 350µA at VCC – 0.1V and sinking 10mA at 0.4V, eliminating external pull-up resistors. The device draws only 28–35µA quiescent current and supports VCC from 1.2V to 5.5V, enabling use across wide-input industrial and battery-powered applications.

Key Specifications

Pinout & Package

SOT-23-3 surface-mount package (3.0mm × 1.7mm footprint), RoHS-compliant, tape-and-reel format (T&R).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326UT30D3+ and TPS3808G30DBVR, the DS1817R-5+T&R offers fixed 150ms timing and proven industrial reliability at lower cost, while trading off trip accuracy and ultra-low IQ for simplicity and ease of integration in cost-sensitive 3.0V embedded systems.

Availability

DS1817R-5+T&R is available at Aetrix Electronics and suitable for industrial control panels, medical handhelds, point-of-sale terminals, and battery-powered sensor nodes requiring stable component supply and long-lifecycle support.

Supply support for DS1817R-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

Analog Devices (via acquisition of Maxim Integrated) designs precision analog, mixed-signal, and power management ICs for industrial, automotive, and communications markets.

The DS1817R-5+T&R belongs to Maxim's EconoReset™ family of supervisory circuits, engineered for cost-effective, single-rail power monitoring and reset generation in resource-constrained embedded systems.

FAQ

What is the exact VCC trip voltage range for DS1817R-5+T&R?

The DS1817R-5+T&R has a guaranteed VCC trip point of 2.98V to 3.15V at -40°C to +85°C, corresponding to a nominal 3.0V threshold with ±5% tolerance. This range is specified in the DC Electrical Characteristics table and applies across the full operating temperature range without derating. The DS1817R-5+T&R uses an internal temperature-compensated reference to maintain accuracy over temperature.

Does DS1817R-5+T&R require an external pull-up resistor on the RST pin?

No, DS1817R-5+T&R does not require an external pull-up resistor because it features a push-pull active-high output stage. The RST pin can source up to 350µA and sink up to 10mA, allowing direct connection to standard CMOS reset inputs. This eliminates BOM components and simplifies layout - a key design advantage confirmed in the Pin Assignment and Electrical Characteristics sections of the DS1817R-5+T&R datasheet.

What is the reset pulse width behavior of DS1817R-5+T&R during power-up and power-down?

During power-up, DS1817R-5+T&R asserts RST high for 100–250ms (typically 150ms) after VCC crosses the trip threshold. During power-down, RST is asserted immediately upon VCC falling below the trip point. Both behaviors are internally timed and independent of external components. The DS1817R-5+T&R datasheet specifies tRST = 100–250ms and tRPD = 2–5µs, confirming deterministic timing critical for µP initialization.

Can DS1817R-5+T&R operate with supply voltages below 3.0V?

Yes, DS1817R-5+T&R operates with VCC from 1.2V to 5.5V per the Recommended DC Operating Conditions table. However, its 3.0V trip point remains fixed - meaning it will assert reset when VCC falls below ~2.98V regardless of input voltage level. Below 2.98V, the device continues functioning down to 1.2V, maintaining reset assertion and consuming only 28–35µA, making it suitable for brownout detection in partially discharged battery systems.

Is DS1817R-5+T&R pin-compatible with other DS1817 variants like DS1817R-10+T&R?

Yes, DS1817R-5+T&R is pin-compatible with all DS1817x variants (e.g., DS1817R-10+T&R, DS1817R-20+T&R) in the same SOT-23-3 package. The only difference is the VCC trip point: 5% (2.98–3.15V), 10% (2.80–2.97V), or 20% (2.47–2.64V). Pinout, timing, output structure, and package dimensions are identical - enabling drop-in replacement when trip tolerance requirements change within the same design.