Analog Devices Inc./Maxim Integrated MXD1817UR22+T

Overview

MXD1817UR22+T from Maxim Integrated is a precision microprocessor reset supervisor IC with active-high push-pull RESET output, factory-set 2.18V reset threshold, 100ms minimum reset timeout, and operation down to VCC = +1V. It monitors +2.5V/+3.0V/+3.3V power rails in portable and industrial embedded systems, ensuring reliable μP initialization during power-up, brownout, and manual reset events.

For engineers reviewing the MXD1817UR22+T datasheet, MXD1817UR22+T pinout, MXD1817UR22+T application, or MXD1817UR22+T equivalent, key selection criteria include its active-high push-pull output configuration, ±2.5% threshold accuracy over -40°C to +105°C, 4μA supply current, SC70/SOT23 package compatibility, and guaranteed RESET validity at low VCC - critical for battery-powered and safety-critical μP monitoring.

Technical Context

The MXD1817UR22+T implements a precision bandgap-based voltage comparator with hysteresis to detect VCC falling below 2.18V (±2.5% over temperature), triggering an active-high RESET assertion. Its internal timer guarantees ≥100ms reset pulse width after VCC recovers above threshold, independent of VCC slew rate.

Unlike open-drain variants, this device uses a push-pull output stage capable of sourcing 350μA while asserted and sinking 10mA when deasserted, eliminating external pullup resistors. It is not equipped with manual-reset debounce circuitry - that feature is exclusive to MXD1813/MXD1818 variants.

Key Specifications

Pinout & Package

SOT23-3 plastic surface-mount package (3-pin, 1.3mm × 2.9mm × 1.0mm), lead(Pb)-free, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TRD3+T and TPS3808G12QDBVRQ1, the MXD1817UR22+T offers a fixed 2.18V active-high reset in standard SOT23-3 with ultra-low 4μA quiescent current - making it optimal for space-constrained, battery-sensitive +2.5V/+3.3V systems where simplicity and low power are prioritized over adjustability or automotive certification.

Availability

MXD1817UR22+T is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, smart energy meters, and automotive infotainment subsystems requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for MXD1817UR22+T 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, communications, computing, and consumer applications.

The MXD1810–MXD1818 family was engineered specifically for low-power, high-accuracy microprocessor reset supervision in space-constrained embedded systems - emphasizing factory-trimmed thresholds, minimal external components, and wide-temperature reliability.

FAQ

What is the reset threshold voltage of the MXD1817UR22+T?

The MXD1817UR22+T has a factory-set reset threshold of 2.18V, with ±2.5% accuracy guaranteed over the full operating temperature range of -40°C to +105°C. This value is laser-trimmed during production and applies specifically to the "R22" suffix variant within the MXD1815–MXD1818 series for +2.5V/+3.0V/+3.3V systems.

Does the MXD1817UR22+T support manual reset functionality?

No, the MXD1817UR22+T does not include manual reset debounce circuitry. That feature is exclusive to the MXD1813 and MXD1818 variants. The MXD1817UR22+T provides only power-supply monitoring and automatic reset assertion - it lacks the internal logic to detect and debounce external pushbutton signals on the RESET pin.

What is the output configuration of the MXD1817UR22+T?

The MXD1817UR22+T features an active-high push-pull RESET output. When VCC drops below 2.18V, RESET transitions from low to high and remains high for at least 100ms after VCC rises above threshold. This eliminates the need for an external pullup resistor and allows direct interfacing with μP reset pins requiring active-high assertion.

Can the MXD1817UR22+T operate reliably at very low supply voltages?

Yes, the MXD1817UR22+T guarantees valid RESET output down to VCC = +1.0V, as confirmed in its Absolute Maximum Ratings and Electrical Characteristics tables. This ensures deterministic reset behavior during deep brownout conditions - a key differentiator versus many competing supervisors that lose output validity below 1.5V.

Is the MXD1817UR22+T pin-compatible with other devices in the MXD181x family?

The MXD1817UR22+T shares the same SOT23-3 pinout (RESET, VCC, GND) with all MXD181x variants, including MXD1810–MXD1813 and MXD1815–MXD1818. However, output polarity (active-high vs. active-low) and internal features (e.g., manual reset) differ - so functional substitution requires verification of reset logic level and system timing requirements, not just pin alignment.