Analog Devices Inc./Maxim Integrated MXD1816XR29

Overview

MXD1816XR29 from Maxim Integrated is an open-drain, active-low microprocessor reset supervisor IC designed for +2.5V/+3.0V/+3.3V systems. It monitors VCC and asserts RESET when voltage falls below 2.88V (±2.5% accuracy), maintains reset for ≥100ms after VCC recovery, features internal 5.5kΩ pullup, consumes only 4μA typical supply current, and operates across –40°C to +105°C - ideal for portable battery-powered controllers and embedded μP monitoring.

For engineers reviewing the MXD1816XR29 datasheet, MXD1816XR29 pinout, MXD1816XR29 application, or MXD1816XR29 equivalent, key selection criteria include its 2.88V factory-set reset threshold, SC70-3 open-drain output configuration, manual-reset immunity (not supported), guaranteed RESET validity down to VCC = +1V, and compatibility with bidirectional μP reset pins without external pullups.

Technical Context

The MXD1816XR29 implements a precision bandgap-based voltage comparator with hysteresis to detect VCC drops below its factory-trimmed 2.88V threshold. Its internal timer guarantees a minimum 100ms reset timeout after VCC rises above threshold, independent of supply ramp rate.

As an open-drain device, MXD1816XR29 drives RESET low during fault conditions while relying on its integrated 5.5kΩ pullup resistor to maintain high state otherwise - enabling direct interface with bidirectional microcontroller reset pins (e.g., Motorola 68HC11) and eliminating need for external components.

Key Specifications

Pinout & Package

MXD1816XR29 is housed in a 3-pin SC70 package (outline X3-2), measuring 2.0mm × 1.25mm × 0.95mm, optimized for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MXD1816XR29, MAX809TRD3-T offers lower quiescent current but demands external pullup for open-drain operation, while TPS3808G125DBVR adds configurability and watchdog capability at the cost of pin count and BOM complexity - MXD1816XR29 delivers optimal balance of integration, precision, and footprint for fixed-threshold 3.3V systems.

Availability

MXD1816XR29 is available at Aetrix Electronics and suitable for computers and controllers, intelligent instruments, set-top boxes, and portable/battery-powered equipment requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MXD1816XR29 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 analog, mixed-signal, and power management ICs for industrial, communications, and consumer applications.

The MXD1810–MXD1818 family was designed specifically for low-power, space-constrained microprocessor reset supervision in portable and industrial systems - emphasizing precision threshold accuracy, minimal external components, and wide temperature operation.

FAQ

What is the exact reset threshold voltage of MXD1816XR29 and how tightly is it specified?

The MXD1816XR29 has a factory-set reset threshold of 2.88V, with guaranteed accuracy of ±2.5% over the full operating temperature range (–40°C to +105°C). This specification ensures reliable detection of brownout conditions on 3.3V rails without requiring system-level calibration or trimming. The value is laser-trimmed during production and documented in the Electrical Characteristics table of the official datasheet.

Does MXD1816XR29 support manual reset functionality via the RESET pin?

No, MXD1816XR29 does not support manual reset detection. Only the MXD1813 and MXD1818 variants in the family include debounced manual-reset circuitry that triggers on a >1.5μs low pulse to the RESET pin. MXD1816XR29 is configured solely for power-supply monitoring and lacks this feature - its RESET pin serves only as an open-drain output, not an input.

What package type and dimensions does MXD1816XR29 use, and is it RoHS-compliant?

MXD1816XR29 is supplied in a 3-pin SC70 package (outline X3-2), measuring 2.0mm × 1.25mm × 0.95mm. It is available in lead(Pb)-free packaging - indicated by the "+T" suffix in ordering codes - and fully complies with RoHS Directive 2011/65/EU. The SC70 footprint enables high-density PCB layouts typical in portable electronics.

Can MXD1816XR29 interface directly with a microcontroller that has a bidirectional reset pin?

Yes, MXD1816XR29 can interface directly with bidirectional reset pins (e.g., Motorola 68HC11) because its open-drain RESET output and integrated 5.5kΩ pullup resistor eliminate the need for external components. When the microcontroller asserts reset, it pulls the shared line low; when idle, MXD1816XR29's internal pullup holds the line high - enabling true wired-OR reset arbitration without signal contention.

What is the minimum supply voltage at which MXD1816XR29 guarantees valid RESET output logic states?

MXD1816XR29 guarantees correct RESET logic state (high or low) down to VCC = +1V. Below this level, output behavior is not specified. This ensures deterministic reset signaling during deep brownout conditions common in battery-powered systems, where VCC may sag to ~1.1V before cutoff - supporting robust fail-safe operation in portable equipment.