Analog Devices Inc./Maxim Integrated MXD1816XR26+

Overview

MXD1816XR26+ from Maxim Integrated is an open-drain, active-low microprocessor reset supervisor IC designed for +2.5V/+3.0V/+3.3V digital systems. It monitors VCC and asserts RESET when supply voltage falls below 2.55V (±2.5% over temperature), maintains reset for ≥100ms after VCC recovery, consumes only 4μA typical supply current, and features an internal 5.5kΩ pullup resistor - ideal for portable, battery-powered μP monitoring applications.

For engineers reviewing the MXD1816XR26+ datasheet, MXD1816XR26+ pinout, MXD1816XR26+ application, or MXD1816XR26+ equivalent, key selection criteria include its 2.55V factory-trimmed reset threshold, SC70-3 package footprint, open-drain output compatibility with bidirectional μP reset pins (e.g., Motorola 68HC11), and guaranteed RESET validity down to VCC = +1V.

Technical Context

The MXD1816XR26+ implements a precision bandgap-based voltage comparator with hysteresis to detect VCC drops below its 2.55V threshold, coupled with a monolithic timer that enforces a minimum 100ms reset timeout period upon VCC recovery. Its open-drain RESET output interfaces directly with microcontrollers requiring external pullup or bidirectional reset control.

No external components are required: internal pullup (5.5kΩ) eliminates need for discrete resistors, and transient immunity circuitry suppresses false resets from sub-µs negative-going VCC glitches up to 100µs duration at 200mV overdrive. The device operates across -40°C to +105°C and remains functional down to VCC = +1V.

Key Specifications

Pinout & Package

MXD1816XR26+ is housed in a 3-pin SC70 package (outline X3-2, land pattern 90-0208), measuring 2.0mm × 2.1mm × 0.9mm, rated for -40°C to +105°C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MXD1816XR26+, MAX809TRD2+T offers lower current but lacks internal pullup and has mismatched threshold for 2.5V systems, while TPS3808G125DBVR provides flexibility at the cost of pin count and design complexity - MXD1816XR26+ delivers optimal balance of precision, integration, and footprint for fixed 2.55V supervision.

Availability

MXD1816XR26+ is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, smart home hub controllers, and automotive infotainment subsystems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MXD1816XR26+ 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 high-performance analog, mixed-signal, and power management ICs for industrial, communications, computing, and consumer applications.

The MXD1810–MXD1818 family was designed specifically to replace discrete reset solutions in space- and power-constrained μP systems, delivering factory-trimmed accuracy, zero-component operation, and robust transient immunity in miniature SC70/SOT23 packages.

FAQ

What is the exact reset threshold voltage of MXD1816XR26+ and how stable is it over temperature?

The MXD1816XR26+ has a factory-set reset threshold of 2.55V, with guaranteed accuracy of ±2.5% across the full operating temperature range of -40°C to +105°C. This stability is achieved through laser-trimmed bandgap reference circuitry and is confirmed in the Electrical Characteristics table under VTH for suffix R26. The MXD1816XR26+ maintains this precision without external calibration.

Does MXD1816XR26+ require an external pullup resistor on the RESET pin?

No, MXD1816XR26+ does not require an external pullup resistor. It integrates a 5.5kΩ internal pullup resistor on its open-drain RESET output, as specified in the Electrical Characteristics table under "Internal Pullup Resistor, Open-Drain" for MXD1816. This eliminates the need for discrete components and simplifies PCB layout.

Can MXD1816XR26+ operate reliably when VCC drops below 2.0V?

Yes, MXD1816XR26+ is guaranteed to assert and maintain a valid RESET signal down to VCC = +1.0V, as stated in the Absolute Maximum Ratings and Electrical Characteristics sections. This ensures deterministic μP reset behavior during deep brownout events where many competing supervisors fail to function.

What package type and dimensions does MXD1816XR26+ use?

MXD1816XR26+ uses the 3-pin SC70 package (outline X3-2), measuring 2.0mm × 2.1mm × 0.9mm. This compact footprint is documented in the Package Information section and matches land pattern 90-0208, enabling high-density placement in portable and wearable electronics.

Is MXD1816XR26+ compatible with microcontrollers that have bidirectional reset pins?

Yes, MXD1816XR26+ is fully compatible with microcontrollers featuring bidirectional reset pins (e.g., Motorola 68HC11). Its open-drain, active-low RESET output allows direct connection without level shifters or additional logic, as explicitly noted in the Applications Information section under "Interfacing to μPs with Bidirectional Reset Pins."