Analog Devices Inc./Maxim Integrated DS1811-5+T&R

Overview

DS1811-5+T&R from Maxim Integrated (now Analog Devices) is a 5V precision voltage-monitoring reset IC with open-drain output, designed to automatically restart microprocessors after power failure. It asserts an active-low reset for 150 ms after V_CC returns to tolerance, features a 4.62 V typical trip point, internal 5.5 kΩ pull-up resistor, and operates from -40°C to +85°C in SOT-23 package.

For engineers reviewing the DS1811-5+T&R datasheet, DS1811-5+T&R pinout, DS1811-5+T&R application, or DS1811-5+T&R equivalent, key selection criteria include reset timeout accuracy, supply voltage trip threshold tolerance (±0.13 V), open-drain drive capability (10 mA sink), and compatibility with 5V microcontroller reset inputs requiring guaranteed minimum 100 ms assertion time.

Technical Context

The DS1811-5+T&R integrates a precision temperature-compensated voltage reference and comparator to monitor V_CC against a fixed 4.50–4.75 V trip window. Its internal power-fail detection circuit triggers RST assertion within 2–5 µs of out-of-tolerance detection, and holds reset active for 100–300 ms after recovery - with 150 ms typical - ensuring stable processor boot.

This device implements a single-supply, self-contained reset generator with no external timing components required. The open-drain RST output supports wired-OR configurations and interfaces directly to TTL/CMOS inputs, while the internal 3.5–7.5 kΩ pull-up resistor eliminates need for discrete biasing in many applications.

Key Specifications

Pinout & Package

SOT-23-3 surface-mount package with 1.3 mm × 2.9 mm footprint and 0.95 mm height; RoHS-compliant, lead-free termination.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809SEUR+T and TPS3808G01DBVR, the DS1811-5+T&R offers lowest component count for fixed 5V systems due to its integrated pull-up and factory-trimmed trip point, reducing layout complexity and qualification effort for cost-sensitive industrial designs.

Availability

DS1811-5+T&R is available at Aetrix Electronics and suitable for industrial control panels, smart metering hardware, and network infrastructure equipment requiring stable component supply with guaranteed long-term availability.

Supply support for DS1811-5+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 and mixed-signal ICs for industrial, communications, and computing applications.

The DS1811-5+T&R belongs to the EconoReset™ family - ultra-low-cost, single-function reset supervisors targeting high-volume embedded systems where reliability and minimal BOM count are critical.

FAQ

What is the exact V_CC trip voltage range for DS1811-5+T&R?

The DS1811-5+T&R has a guaranteed V_CC trip point between 4.50 V and 4.75 V, with 4.62 V typical. This range is factory-trimmed and temperature-compensated to maintain accuracy across -40°C to +85°C operation. The DS1811-5+T&R uses this fixed threshold to detect 5V supply brownout conditions without external resistors or calibration.

Does DS1811-5+T&R require an external pull-up resistor on the RST pin?

No, the DS1811-5+T&R includes an internal 5.5 kΩ pull-up resistor connected to V_CC, enabling direct interface to standard 5V logic inputs. An external pull-up is only needed if higher voltage levels (e.g., 12V) or stronger drive strength are required. The DS1811-5+T&R's integrated resistor reduces BOM count and PCB area in typical applications.

How long does DS1811-5+T&R hold the reset signal active after power recovery?

The DS1811-5+T&R holds RST active for 100–300 ms after V_CC returns to tolerance, with 150 ms typical. This guaranteed minimum duration ensures microprocessors and associated peripherals stabilize before release. The DS1811-5+T&R achieves this timing internally without external capacitors, simplifying design versus RC-based reset circuits.

Can DS1811-5+T&R be used with 3.3V microcontrollers?

Yes, the DS1811-5+T&R's open-drain RST output is compatible with 3.3V logic when pulled up to 3.3V externally - though its V_CC trip point remains fixed at ~4.62 V. For true 3.3V supply monitoring, a different variant like DS1811-33 would be required. The DS1811-5+T&R must be powered from the 5V rail it monitors, not the 3.3V domain.

What package type is supplied for DS1811-5+T&R?

The DS1811-5+T&R is supplied in SOT-23-3 package (1.3 mm × 2.9 mm), tape-and-reel format (T&R). This compact surface-mount package supports automated assembly and meets industrial thermal requirements. Pinout matches TO-92 variant electrically but differs mechanically - the DS1811-5+T&R uses SOT-23 exclusively per ordering code "+T&R".