Analog Devices Inc./Maxim Integrated MXD1811XR41+

Overview

MXD1811XR41+ from Maxim Integrated is an open-drain, active-low microprocessor reset supervisor IC designed for +5V systems. It monitors VCC and asserts RESET when voltage falls below 4.12V (±2.5% over temperature), maintains reset for ≥100ms after recovery, and features an internal 5.5kΩ pullup resistor. It operates from -40°C to +105°C with 4μA supply current and is used in portable equipment and critical μP monitoring.

For engineers reviewing the MXD1811XR41+ datasheet, MXD1811XR41+ pinout, MXD1811XR41+ application, or MXD1811XR41+ equivalent, key selection criteria include its 4.12V reset threshold, SC70-3 open-drain output, manual-reset immunity (not supported), guaranteed RESET validity down to VCC = +1V, and compatibility with bidirectional μP reset pins without external pullups.

Technical Context

The MXD1811XR41+ implements a precision bandgap-based reset comparator with transient immunity, asserting RESET low when VCC drops below its factory-trimmed 4.12V threshold. Its open-drain output structure enables direct interfacing with bidirectional microcontroller reset pins (e.g., Motorola 68HC11) and eliminates need for external pullup resistors.

Unlike MXD1813/MXD1818 variants, it lacks manual-reset debounce circuitry and does not respond to external low pulses on RESET. Its reset timeout is fixed at ≥100ms after VCC rise, and it guarantees functional RESET/RESET logic states down to VCC = +1V - critical for brownout detection in battery-powered systems.

Key Specifications

Pinout & Package

MXD1811XR41+ is housed in a 3-pin SC70 package (outline X3-2), measuring 2.0mm × 1.25mm × 0.9mm, optimized for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor reset supervision applications.

Compared with MAX809TRD3+T and TPS3808G33DBVR, MXD1811XR41+ uniquely combines 4.12V precision threshold, SC70 footprint, open-drain output with integrated pullup, and guaranteed operation down to VCC = +1V - making it optimal for space-constrained +5V μP systems requiring minimal external components and bidirectional reset support.

Availability

MXD1811XR41+ is available at Aetrix Electronics and suitable for computers and controllers, intelligent instruments, and portable/battery-powered equipment requiring stable component supply across industrial temperature ranges and long-lifecycle programs.

Supply support for MXD1811XR41+ 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) is a semiconductor company specializing in analog, mixed-signal, and power-management ICs for industrial, computing, and communications markets.

The MXD1810–MXD1818 family was designed specifically for low-power, precision microprocessor reset supervision in space-constrained +2.5V to +5V systems - emphasizing factory-trimmed thresholds, ultra-low ICC, and robust transient immunity.

FAQ

What is the exact reset threshold voltage of MXD1811XR41+ and how accurate is it over temperature?

The MXD1811XR41+ has a factory-set reset threshold of 4.12V, with guaranteed accuracy of ±2.5% across the full operating temperature range of -40°C to +105°C. This value is specified in the Electrical Characteristics table under "MXD181__ R41" row, with min/typ/max values of 4.00V/4.12V/4.24V. The ±2.5% tolerance ensures reliable detection of 5V rail collapse without false triggers during thermal cycling.

Does MXD1811XR41+ support manual reset via an external pushbutton?

No, MXD1811XR41+ does not support manual reset. Only MXD1813 and MXD1818 variants include debounced manual-reset detection (requiring RESET pin low for ≥1.5μs). MXD1811XR41+ is a dedicated power-supply monitor with no input pin functionality beyond VCC and GND - its RESET pin is output-only, open-drain, and active-low.

What package type and dimensions does MXD1811XR41+ use?

MXD1811XR41+ uses the 3-pin SC70 package (outline X3-2), with body dimensions of 2.0mm × 1.25mm × 0.9mm and lead pitch of 0.65mm. This is confirmed in the "Package Information" section and "Ordering Information" table, where "MXD1811XR__-T" denotes SC70 packaging. The "+" suffix indicates lead(Pb)-free RoHS-compliant construction.

Can MXD1811XR41+ interface directly with a microcontroller that has a bidirectional reset pin?

Yes, MXD1811XR41+ is explicitly designed for this use case. Its open-drain, active-low RESET output - combined with the internal 5.5kΩ pullup resistor - allows direct connection to bidirectional reset pins (e.g., Motorola 68HC11) without external components. As stated in "Applications Information", this eliminates the need for an external pullup and enables either device to assert reset on the shared line.

What is the minimum VCC voltage at which MXD1811XR41+ guarantees valid RESET output logic states?

MXD1811XR41+ guarantees valid RESET/RESET logic states down to VCC = +1.0V, as specified in the Absolute Maximum Ratings and Electrical Characteristics tables. This ensures deterministic reset behavior during deep brownout conditions - critical for preventing undefined μP states in battery-backed or unregulated supply applications. Note that validity ends at +1.0V; operation below this is not characterized.