Analog Devices Inc./Maxim Integrated MXD1816UR29+

Overview

MXD1816UR29+ from Maxim Integrated is a low-power microprocessor reset supervisor IC designed for +2.5V/+3.0V/+3.3V digital systems. It provides active-low, open-drain RESET output with internal 5.5kΩ pullup resistor, 2.88V ±2.5% factory-trimmed reset threshold, 100ms minimum reset timeout, and operates from -40°C to +105°C in SOT23-3 package - used for reliable power-on reset in portable microcontroller applications.

For engineers reviewing the MXD1816UR29+ datasheet, MXD1816UR29+ pinout, MXD1816UR29+ application, or MXD1816UR29+ equivalent, key selection criteria include reset threshold accuracy over temperature, guaranteed RESET validity down to VCC = +1V, manual-reset debounce capability (not supported), open-drain interface compatibility with bidirectional μP reset pins, and lead-free SOT23-3 packaging compliance.

Technical Context

The MXD1816UR29+ implements a precision bandgap-based voltage monitor with comparator hysteresis to reject fast VCC transients, ensuring robust brownout detection without false triggering. Its internal reset timer guarantees a minimum 100ms assertion period after VCC rises above the 2.88V threshold, meeting JEDEC JESD84-B4.8 power-up timing requirements for embedded microcontrollers.

As an open-drain active-low supervisor, MXD1816UR29+ interfaces directly with bidirectional μP reset pins (e.g., Motorola 68HC11) without external pullup components. It draws only 4μA typical supply current at +3.6V and maintains valid logic states across its full operating range of +1.2V to +5.5V VCC.

Key Specifications

Pinout & Package

MXD1816UR29+ is housed in a RoHS-compliant, lead-free 3-pin SOT23 package (U3-1 outline), footprint-compatible with industry-standard 3-pin supervisory ICs and optimized for high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MXD1816UR29+, MAX809TRD3+T offers stronger push-pull drive but lacks integrated pullup for bidirectional interfaces, while TPS3808G33DBVR provides timeout adjustability at the cost of higher quiescent current and larger package - MXD1816UR29+ balances minimal footprint, ultra-low ICC, and seamless bidirectional reset support.

Availability

MXD1816UR29+ is available at Aetrix Electronics and suitable for computers and controllers, intelligent instruments, and portable/battery-powered equipment requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for MXD1816UR29+ 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 consumer applications, emphasizing reliability, integration, and low-power operation.

The MXD1810–MXD1818 family targets cost-sensitive, space-constrained embedded systems requiring dependable power-on reset without external components - optimized for portable, battery-operated, and industrial-grade microcontroller platforms.

FAQ

What is the exact reset threshold voltage of MXD1816UR29+ and how tightly is it specified?

The MXD1816UR29+ has a factory-set reset threshold of 2.88V with ±2.5% accuracy over the full -40°C to +105°C temperature range. This value is trimmed during production and guaranteed per the Electrical Characteristics table; typical performance shows 2.80V to 2.97V across temperature and process variation. The 2.88V point corresponds to the "R29" suffix in the part number and is validated for +2.5V/+3.0V/+3.3V supply monitoring applications.

Does MXD1816UR29+ support manual reset via an external pushbutton?

No, MXD1816UR29+ does not include manual reset or pushbutton debounce functionality. That feature is exclusive to the MXD1813 and MXD1818 variants (e.g., MXD1813UR29+). MXD1816UR29+ provides only power-supply monitoring and automatic reset assertion on VCC drop below 2.88V. Its RESET pin is open-drain active-low and not designed to detect or debounce external switch signals.

What package type and lead finish does MXD1816UR29+ use?

MXD1816UR29+ is supplied in a 3-pin SOT23 package (outline U3-1) with lead-free (Pb-free) termination, indicated by the "+" suffix in the part number. It complies with RoHS Directive 2011/65/EU and uses matte tin plating over copper leadframe. The package is tape-and-reel packaged in 2500-unit reels and rated for reflow soldering per JEDEC J-STD-020.

Can MXD1816UR29+ operate reliably at VCC = +1.2V?

Yes, MXD1816UR29+ is fully specified to operate down to VCC = +1.2V (minimum) across -40°C to +105°C. Its internal comparator and reset generator remain functional and guarantee correct RESET/RESET logic states at this voltage. However, the open-drain output's sinking capability degrades below +2.7V, so external load conditions should be verified if driving heavy capacitive or resistive loads near the lower VCC limit.

Is MXD1816UR29+ pin-compatible with other members of the MXD181x family?

Yes, all MXD181x devices - including MXD1816UR29+ - share identical 3-pin SOT23 pinout (VCC, RESET, GND) and SC70 pinout, enabling direct substitution within the same package type. Functionality differs by reset threshold, output type (push-pull vs. open-drain), and optional features (e.g., manual reset), but mechanical and electrical interface compatibility is maintained across the family for drop-in replacement where functional requirements align.