Analog Devices Inc./Maxim Integrated MXD1813UR41+

Overview

MXD1813UR41+ from Maxim Integrated is a low-power microprocessor reset supervisor IC designed for +5V systems, featuring open-drain active-low RESET output with debounced manual-reset capability, 4.12V reset threshold (±2.5% over temperature), 100ms minimum reset timeout, and operation down to VCC = +1V. It monitors supply voltage integrity and initiates system reset during power-up, brownout, or push-button events in embedded controllers and portable equipment.

For engineers reviewing the MXD1813UR41+ datasheet, MXD1813UR41+ pinout, MXD1813UR41+ application, or MXD1813UR41+ equivalent, key selection criteria include its factory-trimmed 4.12V threshold, 1.5μs manual-reset detection window, internal 5.5kΩ pullup resistor, -40°C to +105°C operating range, and SOT23-3 package compatibility with DS181x-series designs.

Technical Context

The MXD1813UR41+ integrates a precision voltage comparator with hysteresis, an internal timer for fixed 100ms reset assertion after VCC recovery, and dedicated debouncing logic for external RESET pin transitions. Its open-drain output interfaces directly with bidirectional μP reset pins without external pullups.

It supports manual reset initiation via a logic-low pulse ≥1.5μs on the RESET terminal, triggering a guaranteed 100ms reset timeout independent of VCC behavior. The device maintains valid RESET output state down to VCC = +1V and rejects transients ≤20μs at 4.12V overdrive.

Key Specifications

Pinout & Package

MXD1813UR41+ is housed in a 3-pin SOT23 package (JEDEC MO-178AA), with 1.3mm pitch, 2.9mm × 1.6mm body, and exposed pad optional per manufacturer variant. Pin 1 is RESET (open-drain active-low), Pin 2 is VCC (supply input and threshold reference), and Pin 3 is GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MXD1813UR41+, MAX809TRD3+T offers simpler reset timing but no manual-reset capability, while TPS3808G33DBVR provides greater flexibility at the cost of larger footprint and higher quiescent current-making MXD1813UR41+ optimal for space-constrained, push-button-enabled 5V systems needing minimal BOM and guaranteed 100ms hold time.

Availability

MXD1813UR41+ is available at Aetrix Electronics and suitable for industrial controller monitoring, portable medical device power management, set-top box power sequencing, network router system initialization, and critical μP brownout protection requiring stable component supply across extended temperature ranges.

Supply support for MXD1813UR41+ 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 and mixed-signal ICs for power, sensing, connectivity, and interface applications.

The MXD1810–MXD1813/MXD1815–MXD1818 product line delivers ultra-low-power, precision reset supervision for microprocessor-based systems operating across harsh industrial and portable environments.

FAQ

What is the exact reset threshold voltage of the MXD1813UR41+?

The MXD1813UR41+ has a factory-set reset threshold of 4.12V, with guaranteed tolerance of ±2.5% over the full operating temperature range (-40°C to +105°C). This value is confirmed in the Electrical Characteristics table under "MXD181_ _ R41" entry, where VTH min = 4.00V, typ = 4.12V, max = 4.24V at TA = -40°C to +105°C.

Does the MXD1813UR41+ support manual reset, and how does it work?

Yes, the MXD1813UR41+ supports debounced manual reset via its RESET pin: a logic-low pulse ≥1.5μs triggers a guaranteed 100ms reset timeout period. This feature is exclusive to MXD1813/MXD1818 variants and eliminates external debounce components-critical for reliable operation with mechanical switches in portable equipment.

What package type and footprint does the MXD1813UR41+ use?

The MXD1813UR41+ uses a 3-pin SOT23 package (JEDEC MO-178AA), identical in outline and land pattern to the DS181x family. Pin 1 = RESET (open-drain), Pin 2 = VCC, Pin 3 = GND. The "U" in the part number explicitly denotes SOT23 packaging, and the "+" suffix indicates lead(Pb)-free RoHS-compliant construction.

Can the MXD1813UR41+ operate reliably at low supply voltages?

Yes, the MXD1813UR41+ guarantees correct RESET/RESET logic state down to VCC = +1.0V, as specified in Absolute Maximum Ratings and Electrical Characteristics. Its internal comparator and timer remain functional through deep brownout, enabling robust reset assertion even as 5V rails collapse toward 1V during power failure.

Is an external pullup resistor required for the MXD1813UR41+ RESET output?

No, the MXD1813UR41+ includes an internal 5.5kΩ pullup resistor on its open-drain RESET output, eliminating the need for external components. This is explicitly documented in the Electrical Characteristics table ("Internal Pullup Resistor, Open-Drain") and Pin Descriptions, confirming RP = 3.1kΩ (min) to 7.5kΩ (max) for MXD1813/MXD1818 variants.