Analog Devices Inc./Maxim Integrated MXD1813UR44+T

Overview

MXD1813UR44+T from Maxim Integrated is a low-power microprocessor reset supervisor IC designed for +5V systems, featuring an open-drain active-low RESET output with internal 5.5kΩ pullup resistor, factory-set 4.37V reset threshold (±2.5% over temperature), 100ms minimum reset timeout, and debounced manual-reset detection triggered by ≥1.5μs low pulse on RESET pin. It monitors VCC in embedded controllers and portable equipment to prevent code-execution errors during power-up, brownout, or push-button-initiated reset.

For engineers reviewing the MXD1813UR44+T datasheet, MXD1813UR44+T pinout, MXD1813UR44+T application, or MXD1813UR44+T equivalent, key selection criteria include its 4.37V threshold accuracy, manual-reset debounce timing, open-drain drive capability (10mA sink), guaranteed operation down to VCC = +1V, and compatibility with mechanical switch interfaces in space-constrained industrial and battery-powered designs.

Technical Context

The MXD1813UR44+T implements a precision voltage comparator with hysteresis-free threshold detection at 4.37V, coupled to a monostable timer that asserts RESET for ≥100ms after VCC rises above threshold or after release of a debounced manual reset signal. Its internal circuitry rejects transients ≤1.5μs duration when VCC falls below threshold by up to 100mV.

As an open-drain active-low supervisor, it interfaces directly with bidirectional μP reset pins without external pullups and supports manual reset initiation via the same RESET pin-functioning as both input (for push-button detect) and output (for reset assertion)-with built-in filtering to suppress mechanical switch bounce.

Key Specifications

Pinout & Package

MXD1813UR44+T is housed in a 3-pin SOT23 package (U3-1 outline), measuring 2.92mm × 1.3mm × 1.0mm, rated for -40°C to +105°C operation and RoHS-compliant (lead-free).

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, MXD1813UR44+T uniquely combines 4.37V precision threshold, integrated manual-reset debounce, open-drain output with internal pullup, and ultra-low 4μA supply current in a 3-pin SOT23 - making it optimal for cost-sensitive, space-constrained +5V systems requiring robust human-interface reset capability.

Availability

MXD1813UR44+T is available at Aetrix Electronics and suitable for industrial controller monitoring, portable medical device power management, set-top box power sequencing, embedded network router supervision, and battery-backed data loggers requiring stable component supply across extended temperature ranges.

Supply support for MXD1813UR44+T 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, and interface applications.

The MXD1810–MXD1813/MXD1815–MXD1818 product line delivers low-power, precision reset supervision for microprocessor-based systems, targeting portable, industrial, and consumer electronics where reliability, small size, and minimal external components are essential.

FAQ

What is the exact reset threshold voltage of MXD1813UR44+T and how accurate is it over temperature?

The MXD1813UR44+T has a factory-set reset threshold of 4.37V, specified with ±2.5% accuracy across the full operating temperature range of -40°C to +105°C. This value is guaranteed by design and verified during production testing at +25°C, with limits over temperature ensured through characterization and process control - not statistical estimation. The MXD1813UR44+T maintains this accuracy without external calibration or trimming components.

Does MXD1813UR44+T support manual reset, and how does its debounce function work?

Yes, MXD1813UR44+T supports hardware-debounced manual reset via its RESET pin, which acts as both output and input. A logic-low pulse ≥1.5μs on RESET initiates a 100ms minimum reset timeout period; shorter pulses are ignored, effectively filtering mechanical switch bounce. The MXD1813UR44+T integrates this detection logic internally - no external RC network or firmware polling is required. Release of the external switch triggers the reset period.

What output type does MXD1813UR44+T use, and what are its drive capabilities?

MXD1813UR44+T features an open-drain, active-low RESET output with an internal 5.5kΩ pullup resistor to VCC. It can sink up to 10mA at VOUT = 0.4V when asserted, compatible with standard CMOS and TTL inputs. The open-drain architecture allows wired-OR connection with other reset sources and eliminates need for external pullup resistors - a key advantage over push-pull alternatives like MXD1812UR44+T.

Can MXD1813UR44+T operate reliably at very low supply voltages?

Yes, MXD1813UR44+T is guaranteed to maintain correct RESET logic state down to VCC = +1.0V, and operates across a full supply range of +1.0V to +5.5V. This ensures deterministic reset behavior during deep brownout conditions, unlike many competitors that lose output validity below +1.8V. However, for applications requiring valid RESET down to VCC = 0V, external pulldown/pullup resistors are recommended per Maxim's application guidance - the MXD1813UR44+T itself does not guarantee functionality at 0V.

What package and environmental ratings does MXD1813UR44+T have?

MXD1813UR44+T is supplied in a RoHS-compliant, lead-free 3-pin SOT23 package (U3-1 outline), with dimensions of 2.92mm × 1.3mm × 1.0mm. It is rated for operation from -40°C to +105°C ambient temperature and qualified for industrial-grade reliability, including 150°C junction temperature limit and 300°C soldering temperature tolerance. Tape-and-reel packaging is provided in 2500-unit increments.