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 across -40°C to +105°C. It ensures reliable power-on reset in portable battery-powered equipment.

For engineers reviewing the MXD1816UR29 datasheet, MXD1816UR29 pinout, MXD1816UR29 application, or MXD1816UR29 equivalent, key selection criteria include its 2.88V threshold accuracy, open-drain interface compatibility with bidirectional μP reset pins, manual-reset immunity (not supported), and SC70/SOT23 package footprint constraints.

Technical Context

The MXD1816UR29 implements a precision voltage-monitoring comparator with hysteresis to detect VCC drops below 2.88V, triggering an active-low reset signal. Its internal timer guarantees ≥100ms reset assertion after VCC recovers above threshold, independent of supply rise time.

As an open-drain device, MXD1816UR29 interfaces directly with microcontrollers having bidirectional reset pins (e.g., Motorola 68HC11) without external pullup components. It draws only 4μA typical supply current at +3.6V and maintains valid reset logic down to VCC = +1V.

Key Specifications

Pinout & Package

MXD1816UR29 is housed in a 3-pin SOT23 package (U3-1 outline), with 0.95mm pitch, 1.3mm width, and 2.92mm length. Pin 1 is RESET (open-drain active-low), Pin 2 is VCC (supply input and threshold monitor), 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 MXD1816UR29, MAX809TRD3-T requires external pullup for bidirectional reset pin use, while TPS3808G125DBVR offers lower current and adjustable timing but demands more PCB area and design validation effort.

Availability

MXD1816UR29 is available at Aetrix Electronics and suitable for industrial controllers, portable instrumentation, set-top boxes, and battery-powered embedded systems requiring stable component supply across extended temperature ranges.

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.

The MXD1810–MXD1818 family delivers low-power, factory-trimmed reset supervision for microprocessor-based systems operating on +2.5V to +5V rails, targeting space-constrained and battery-sensitive designs.

FAQ

What is the exact reset threshold voltage of MXD1816UR29 and how is it trimmed?

The MXD1816UR29 has a factory-trimmed reset threshold of 2.88V with ±2.5% accuracy over -40°C to +105°C. This value is laser-trimmed during production and verified per the Reset Threshold Table in the datasheet; the "R29" suffix explicitly denotes the 2.88V variant. MXD1816UR29 achieves this without external components, relying on internal BiCMOS comparator architecture.

Does MXD1816UR29 support manual reset via pushbutton, and what is its debounce behavior?

No, MXD1816UR29 does not support manual reset or debounce functionality. That feature is exclusive to MXD1813/MXD1818 variants (e.g., MXD1818UR29). MXD1816UR29 is an open-drain active-low reset supervisor without RESET pin monitoring; its only trigger is VCC falling below 2.88V. For pushbutton capability, select MXD1818UR29 instead.

What is the maximum sink current capability of the MXD1816UR29 RESET output?

The MXD1816UR29 RESET output can sink up to 10mA when asserted (low), tested at VCC ≥ 2.7V and VOUT = 0.4V. This is sufficient to drive standard CMOS inputs and small LED indicators directly. The internal 5.5kΩ pullup ensures proper high-state voltage level without external components, and the output remains functional down to VCC = +1.2V.

Can MXD1816UR29 be used with a +2.5V supply, and what is its minimum operating voltage?

Yes, MXD1816UR29 is specified for +2.5V/+3.0V/+3.3V systems and operates from VCC = +1.2V to +5.5V. Its 2.88V threshold makes it ideal for +3.3V rails, but it remains functional at +2.5V - though reset will assert continuously since VCC < VTH. The device guarantees valid RESET/RESET logic states down to VCC = +1V, enabling graceful shutdown detection in deep brownout scenarios.

Is MXD1816UR29 pin-compatible with other members of the MXD181x family, and which packages are supported?

Yes, MXD1816UR29 shares identical 3-pin SOT23 (U3-1) and SC70 (X3-2) footprints with all MXD1810–MXD1818 variants. Pin 1 is RESET, Pin 2 is VCC, and Pin 3 is GND across the family. This allows drop-in replacement between thresholds (e.g., R26, R29, R31) and output types (open-drain vs. push-pull) within the same package, simplifying design reuse and inventory management.