Analog Devices Inc./Maxim Integrated DS1811R-5/T&R

Overview

DS1811R-5/T&R from Maxim Integrated (now Analog Devices) is a 5V precision voltage-monitoring supervisor IC with open-drain active-low reset output, 4.62V typical VCC trip point, 150ms reset timeout, and -40°C to +85°C operating range-used for reliable microprocessor power-up sequencing in embedded control systems.

For engineers reviewing the DS1811R-5/T&R datasheet, DS1811R-5/T&R pinout, DS1811R-5/T&R application, or DS1811R-5/T&R equivalent, key selection criteria include guaranteed 4.50V–4.75V trip window, internal 5.5kΩ pull-up, 10mA sink capability, and SOT-23-3 package compatibility with space-constrained PCB layouts.

Technical Context

The DS1811R-5/T&R implements a temperature-compensated bandgap reference and comparator to detect VCC deviations beyond ±5% of nominal 5V. It asserts RST low on power failure and holds reset for 150ms after VCC returns within tolerance-ensuring stable processor initialization without external timing components.

Its open-drain RST output supports wired-OR configurations and interfaces directly with microcontroller reset inputs requiring active-low assertion. The internal 5.5kΩ pull-up eliminates need for external resistor in standard 5V logic systems, while 10mA sink current ensures robust drive into capacitive loads.

Key Specifications

Pinout & Package

SOT-23-3 surface-mount package with 1.3mm × 2.9mm footprint, 0.95mm height, and gull-wing leads-optimized for automated assembly and high-density PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G01DBVR and MAX6326UT46D3+, the DS1811R-5/T&R delivers lowest component count for fixed 5V supervision, integrates its own pull-up for shared-bus operation, and maintains identical trip accuracy-making it optimal for cost-sensitive, high-volume industrial controls where design stability is prioritized over configurability.

Availability

DS1811R-5/T&R is available at Aetrix Electronics and suitable for industrial PLC controllers, smart energy meters, point-of-sale terminals, and network router control boards requiring stable component supply and long-term lifecycle support.

Supply support for DS1811R-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-with emphasis on reliability, accuracy, and integration.

The DS1811R-5/T&R belongs to Maxim's EconoReset™ family of supervisory circuits, engineered specifically for cost-effective, single-supply voltage monitoring in resource-constrained embedded systems without sacrificing trip accuracy or timing consistency.

FAQ

What is the exact VCC trip voltage range specified for DS1811R-5/T&R?

The DS1811R-5/T&R has a guaranteed VCC trip point range of 4.50V (minimum) to 4.75V (maximum), with 4.62V typical-corresponding to a ±5% tolerance around 5V. This specification is tested and characterized across the full -40°C to +85°C operating temperature range and is defined in the DC Electrical Characteristics table of the official DS1811 datasheet.

Does DS1811R-5/T&R require an external pull-up resistor on the RST pin?

No, DS1811R-5/T&R includes an internal 5.5kΩ pull-up resistor on the RST pin, eliminating the need for an external component in standard 5V logic systems. An external pull-up is only required if interfacing to voltages above 5.5V or implementing a multi-drop wired-OR reset bus with other open-drain devices-otherwise, the internal resistor ensures proper high-state termination.

How long does the DS1811R-5/T&R hold the reset signal active after VCC returns to tolerance?

The DS1811R-5/T&R holds the RST signal active for a guaranteed minimum of 100ms and maximum of 300ms after VCC rises back into the in-tolerance window, with 150ms typical. This fixed timeout is internally generated and independent of external components-ensuring consistent microprocessor stabilization time across all units and operating conditions.

Can DS1811R-5/T&R operate with supply voltages below 5V?

Yes, DS1811R-5/T&R functions across a supply range of 1.2V to 5.5V. While its trip point is fixed at ~4.62V, it remains operational and continues to monitor VCC even during brown-out conditions down to 1.2V-allowing it to assert reset before the monitored rail collapses completely and maintain supervision integrity throughout low-voltage transients.

What package type is used for DS1811R-5/T&R, and is it RoHS compliant?

DS1811R-5/T&R is supplied in the SOT-23-3 package (TO-236AB), with lead (Pb)-free and RoHS-compliant construction per Analog Devices' standard product policy. The device carries the "/T&R" suffix indicating tape-and-reel packaging for automated assembly, and mechanical drawings confirm 1.3mm × 2.9mm body dimensions and 0.95mm maximum height.