Analog Devices Inc./Maxim Integrated MXD1816XR23+

Overview

MXD1816XR23+ 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 drops below 2.31V (±2.5% over temperature), holds reset for ≥100ms after VCC recovery, consumes only 4μA typical supply current, and integrates a 5.5kΩ internal pullup resistor - enabling direct interface with bidirectional μP reset pins without external components.

For engineers reviewing the MXD1816XR23+ datasheet, MXD1816XR23+ pinout, MXD1816XR23+ application, or MXD1816XR23+ equivalent, key selection criteria include its factory-trimmed 2.31V reset threshold, SC70-3 package footprint, guaranteed RESET validity down to VCC = +1V, and compatibility with brownout detection in portable and industrial embedded controllers.

Technical Context

The MXD1816XR23+ implements a precision bandgap-based voltage comparator with hysteresis to reject fast VCC transients up to ~100µs (depending on overdrive), and a monolithic timer circuit that guarantees ≥100ms reset timeout after VCC rises above VTH. Its open-drain output architecture allows wired-OR configuration and seamless interfacing with microcontrollers featuring bidirectional reset I/O such as the Motorola 68HC11.

This device belongs to the MXD1815–MXD1818 subfamily optimized for low-voltage systems (2.5V/3.0V/3.3V), excludes manual-reset debouncing (unlike MXD1818), and operates across -40°C to +105°C with full functionality down to VCC = +1.2V - ensuring reliable reset assertion during deep brownout conditions.

Key Specifications

Pinout & Package

MXD1816XR23+ is housed in a 3-pin SC70 package (outline X3-2, land pattern 90-0208), measuring 2.0mm × 2.1mm × 0.9mm with gull-wing leads. The package is RoHS-compliant and lead(Pb)-free (indicated by '+' suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MXD1816XR23+, MAX809TRD2+T offers lower power and higher threshold but demands external biasing, while TPS3808G125DBVR provides voltage adjustability and longer timeout at the cost of non-pin-compatibility and added design overhead.

Availability

MXD1816XR23+ is available at Aetrix Electronics and suitable for industrial PLC controllers, portable medical monitors, set-top box power management, and smart meter microcontroller supervision requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MXD1816XR23+ 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, and consumer applications.

The MXD1815–MXD1818 product line delivers low-power, precision reset supervision for 2.5V/3.0V/3.3V microprocessor systems - engineered to replace discrete reset solutions with minimal footprint and zero external components.

FAQ

What is the exact reset threshold voltage of MXD1816XR23+ and how stable is it over temperature?

The MXD1816XR23+ has a factory-set reset threshold of 2.31V, with guaranteed accuracy of ±2.5% across the full operating temperature range of -40°C to +105°C. This specification is validated by design and production-tested at +25°C, with limits over temperature assured by characterization - ensuring consistent brownout detection in industrial environments where rail stability is critical. The MXD1816XR23+ maintains this performance without external calibration.

Does MXD1816XR23+ support manual reset functionality via an external pushbutton?

No, MXD1816XR23+ does not include manual reset debounce circuitry. That feature is exclusive to the MXD1813 and MXD1818 variants in the family. MXD1816XR23+ provides only power-supply monitoring and automatic reset assertion on VCC dropout. For pushbutton-initiated reset capability, the MXD1818XR23+ - which shares the same 2.31V threshold and SC70 package - is the functionally matched alternative within the family.

Can MXD1816XR23+ be used with microcontrollers that have bidirectional reset pins?

Yes, MXD1816XR23+ is specifically designed for this use case. Its open-drain, active-low RESET output interfaces directly with bidirectional μP reset pins (e.g., Motorola 68HC11) without external components. The integrated 5.5kΩ internal pullup resistor ensures proper logic-high state when not asserted, and the open-drain structure allows multiple devices (e.g., watchdog, power monitor) to share the same reset line - all coordinated through the MXD1816XR23+.

What is the minimum supply voltage at which MXD1816XR23+ guarantees valid RESET output?

MXD1816XR23+ guarantees functional RESET output down to VCC = +1.2V over the full -40°C to +105°C temperature range. Below this voltage, the internal comparator and timer may cease operation, but the device remains latched in reset state. This ensures deterministic behavior during deep brownout events - a key requirement for fail-safe shutdown in smart meters and industrial controllers where data integrity must be preserved until final power loss.

Is MXD1816XR23+ pin-compatible with other devices in the MXD181x family?

Yes, MXD1816XR23+ is pin-compatible with all members of the MXD1810–MXD1818 family in the same package variant - including MXD1815XR23+, MXD1817XR23+, and MXD1818XR23+ in SC70-3. All share identical pinout (RESET/VCC/GND), electrical tolerances, and footprint. This allows design reuse and last-time buy flexibility across threshold voltages and output configurations - provided the application's reset polarity and manual reset requirements align with the selected variant.