Analog Devices Inc./Maxim Integrated MXD1816XR22

Overview

MXD1816XR22 from Maxim Integrated is a low-power, 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 2.18V (±2.5% accuracy), maintains reset for ≥100ms after VCC recovery, features an internal 5.5kΩ pullup resistor, and operates across –40°C to +105°C in SC70-3 packaging - used in portable battery-powered controllers and embedded μC monitoring.

For engineers reviewing the MXD1816XR22 datasheet, MXD1816XR22 pinout, MXD1816XR22 application, or MXD1816XR22 equivalent, key selection criteria include its 2.18V factory-trimmed reset threshold, open-drain output compatibility with bidirectional μP reset pins, 4μA supply current at +3.6V, and manual-reset immunity to switch bounce - critical for reliable power-up sequencing in space-constrained industrial and consumer electronics.

Technical Context

The MXD1816XR22 implements a precision bandgap-based voltage comparator with hysteresis to detect VCC drops below its fixed 2.18V threshold, coupled with a monolithic timer that guarantees ≥100ms reset assertion after VCC rises above threshold. Its open-drain RESET output interfaces directly with μPs like the Motorola 68HC11 without external pullups.

Unlike push-pull variants (e.g., MXD1812), MXD1816XR22 lacks manual-reset debounce logic and does not support external pushbutton-triggered reset - it is strictly a supply-monitoring device. Its internal 5.5kΩ pullup ensures defined logic-high state when RESET is inactive, and its design ignores transients <1.5μs at VTH–VCC = 200mV.

Key Specifications

Pinout & Package

MXD1816XR22 is housed in a 3-pin SC70 package (outline X3-2, land pattern 90-0208), with 0.65mm pitch and exposed pad optional per Maxim's package documentation. 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 MAX809TR29+T and TPS3808G12DBVR, MXD1816XR22 offers the lowest threshold (2.18V) among fixed-voltage reset ICs in SC70, integrates the pullup resistor to simplify bidirectional reset interfacing, and provides superior transient rejection - making it optimal for 2.5V/3.3V battery-backed systems where space and component count are constrained.

Availability

MXD1816XR22 is available at Aetrix Electronics and suitable for industrial PLC I/O modules, portable medical sensors, and smart home gateway designs requiring stable component supply, long-lifecycle availability, and RoHS-compliant packaging.

Supply support for MXD1816XR22 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 computing applications.

The MXD1810–MXD1818 family was engineered to replace discrete reset solutions in space- and power-constrained μP systems, delivering precision voltage monitoring with zero external components across 2.5V–5V supply rails.

FAQ

What is the exact reset threshold voltage of MXD1816XR22 and how tightly is it specified?

The MXD1816XR22 has a factory-set reset threshold of 2.18V, guaranteed over –40°C to +105°C with ±2.5% accuracy. This value is trimmed during production and documented in the Electrical Characteristics table under "MXD181_ _ R22" row; typical performance shows 2.12V (min) to 2.25V (max) across temperature and process variation. The MXD1816XR22 uses BiCMOS process technology to achieve this stability without external calibration.

Does MXD1816XR22 support manual reset via an external pushbutton?

No, MXD1816XR22 does not support manual reset. Only MXD1813 and MXD1818 variants in the family include debounced manual-reset detection logic triggered by a >1.5μs low pulse on the RESET pin. MXD1816XR22 is a dedicated supply-monitoring device with no internal circuitry to interpret external button presses - its RESET pin functions solely as an open-drain output.

Can MXD1816XR22 be used with a microcontroller that has a bidirectional reset pin?

Yes, MXD1816XR22 is explicitly 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 internal 5.5kΩ pullup resistor ensures a defined high state when inactive, and the output can be pulled low by either the MXD1816XR22 or the μP - enabling coordinated reset arbitration in multi-master systems.

What is the maximum supply voltage the MXD1816XR22 can tolerate on its VCC pin?

The absolute maximum rating for VCC on MXD1816XR22 is +6.0V, but the functional operating range is 1.2V to 5.5V. Operation above 5.5V risks permanent damage, while operation below 1.2V may result in undefined reset behavior. The device guarantees correct RESET/RESET logic states down to VCC = 1.2V, and its reset comparator remains active even as VCC declines toward 1.0V (absolute min).

Is MXD1816XR22 available in lead-free packaging and what is its RoHS status?

Yes, MXD1816XR22 is available in lead(Pb)-free packaging. Per Maxim's ordering information, the "+T" suffix denotes RoHS-compliant, lead-free tape-and-reel packaging (e.g., MXD1816XR22+T), while "-T" indicates standard leaded packaging. Both versions share identical electrical specifications and thermal performance, and the SC70 package outline (X3-2) is qualified for reflow soldering per JEDEC J-STD-020.