Analog Devices Inc./Maxim Integrated MXD1815UR22

Overview

MXD1815UR22 from Maxim Integrated is a precision low-power microprocessor reset supervisor IC designed for +2.5V/+3.0V/+3.3V digital systems. It monitors VCC and asserts an active-low push-pull RESET signal when supply voltage falls below 2.18V, maintains reset for ≥100ms after VCC recovery, draws only 4μA typical supply current, and operates across –40°C to +105°C - enabling reliable power-on reset in portable battery-powered controllers.

For engineers reviewing the MXD1815UR22 datasheet, MXD1815UR22 pinout, MXD1815UR22 application, or MXD1815UR22 equivalent, key selection criteria include its factory-trimmed 2.18V reset threshold (±2.5% over temperature), guaranteed RESET validity down to VCC = +1V, immunity to fast VCC transients, and compatibility with space-constrained SOT23-3 layouts.

Technical Context

The MXD1815UR22 implements a precision bandgap-based voltage comparator with hysteresis to detect VCC drops below its fixed 2.18V threshold, triggering a monostable timer that holds RESET asserted for a minimum 100ms timeout period upon VCC rise. Its internal architecture eliminates external components while ensuring robust operation during brownout and power-up sequencing.

This device belongs to the MXD1815–MXD1818 subfamily optimized for 2.5V/3.0V/3.3V systems and features a push-pull active-low RESET output - unlike open-drain variants - enabling direct drive of μP reset inputs without external pullups. It guarantees functional reset assertion even as VCC declines to +1V, supporting fail-safe behavior in low-voltage fault conditions.

Key Specifications

Pinout & Package

MXD1815UR22 is housed in a 3-pin SOT23 package (U3-1 outline) with 2.92mm × 1.3mm body size and standard 0.95mm lead pitch. The package supports reflow soldering and is available in both leaded and RoHS-compliant lead(Pb)-free versions.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MXD1815UR22, MAX809TRD3-T offers higher threshold and lower accuracy - limiting use in 2.5V/3.3V brownout detection - while TPS3808G12DBVR trades factory-trimmed precision and simplicity for adjustability and lower current, requiring additional components and layout area.

Availability

MXD1815UR22 is available at Aetrix Electronics and suitable for industrial controllers, portable medical devices, smart energy meters, and point-of-sale terminals requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for MXD1815UR22 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, mixed-signal, and power management ICs for industrial, computing, and communications markets.

The MXD1815UR22 belongs to the MXD1815–MXD1818 family of low-power μP reset supervisors targeting compact, battery-sensitive applications in 2.5V/3.0V/3.3V systems - emphasizing accuracy, minimal footprint, and guaranteed low-voltage operation.

FAQ

What is the exact reset threshold voltage of MXD1815UR22 and how stable is it over temperature?

The MXD1815UR22 has a factory-set reset threshold of 2.18V, specified with ±2.5% accuracy over the full –40°C to +105°C operating range. This stability is achieved through laser-trimmed bandgap references and on-die compensation, ensuring consistent brownout detection across industrial thermal environments without external calibration.

Does MXD1815UR22 support manual reset functionality via an external pushbutton?

No, MXD1815UR22 does not include manual reset detection. That feature is exclusive to the MXD1813/MXD1818 variants (e.g., MXD1818UR22), which incorporate debounced push-button sensing on the RESET pin. MXD1815UR22 provides only power-supply monitoring and automatic reset assertion.

Can MXD1815UR22 operate reliably when VCC drops below 2.0V?

Yes - MXD1815UR22 is explicitly guaranteed to maintain valid RESET logic states down to VCC = +1.0V. Its internal circuitry remains functional and asserts or deasserts RESET correctly even at this low voltage, making it suitable for deep brownout scenarios where other supervisors fail.

What is the maximum sink/source capability of the MXD1815UR22 RESET output?

The MXD1815UR22 RESET pin delivers up to 10mA sink current when asserted (low) and sources ~350μA when deasserted (high). This push-pull drive strength allows direct interfacing with most μP reset inputs without external buffers or pullup resistors, simplifying interface design.

Is MXD1815UR22 pin-compatible with legacy DS181x reset ICs?

Yes - MXD1815UR22 uses the same SOT23-3 pinout and electrical behavior as the DS181x family (e.g., DS1815R22), enabling drop-in replacement in existing designs. Both share identical VCC–GND–RESET pin assignments, voltage thresholds, and timing characteristics, minimizing redesign effort.