Analog Devices Inc./Maxim Integrated MXD1817UR31+T

Overview

MXD1817UR31+T from Maxim Integrated is a low-power microprocessor reset supervisor IC in SOT23-3 package, featuring active-high push-pull RESET output, factory-set 3.06V reset threshold (±2.5% over temperature), 100ms minimum reset timeout, and guaranteed operation down to VCC = +1V. It monitors +2.5V/+3.0V/+3.3V power rails in portable embedded systems requiring reliable power-on reset and brownout protection.

For engineers reviewing the MXD1817UR31+T datasheet, MXD1817UR31+T pinout, MXD1817UR31+T application, or MXD1817UR31+T equivalent, key selection criteria include reset threshold accuracy, active-high output logic, manual-reset absence, supply current at 4µA (typ), and compatibility with battery-powered μP systems operating from -40°C to +105°C.

Technical Context

The MXD1817UR31+T implements a precision bandgap-based voltage comparator with hysteresis to detect VCC drops below 3.06V, triggering an active-high RESET signal. Its internal timer ensures reset remains asserted for ≥100ms after VCC recovers above threshold, independent of VCC slew rate.

Unlike MXD1813/MXD1818 variants, MXD1817UR31+T lacks manual-reset input detection and debouncing circuitry. It uses push-pull output architecture-no external pullup required-and guarantees valid RESET logic state even as VCC declines to +1V, enabling robust reset assertion during deep brownout conditions.

Key Specifications

Pinout & Package

MXD1817UR31+T is housed in a 3-pin SOT23 package (outline U3-1). Pin 1 = VCC (supply input and threshold monitor node); Pin 2 = RESET (active-high push-pull output); Pin 3 = GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MXD1817UR31+T, MAX809TRD3+T offers tighter threshold tolerance but requires redesign for active-low signaling, while TPS3808G30DBVR reduces current draw by 75% but adds unnecessary manual-reset circuitry and changes reset polarity-neither provides drop-in replacement capability due to output logic mismatch.

Availability

MXD1817UR31+T is available at Aetrix Electronics and suitable for industrial PLC controllers, portable medical monitors, smart energy meters, and automotive infotainment head units requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MXD1817UR31+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 and mixed-signal ICs for industrial, communications, computing, and consumer applications.

The MXD1810–MXD1818 family targets cost-sensitive, space-constrained embedded systems requiring highly reliable, low-power reset supervision with factory-trimmed thresholds and minimal external components.

FAQ

What is the exact reset threshold voltage of MXD1817UR31+T and how stable is it over temperature?

The MXD1817UR31+T has a factory-set reset threshold of 3.06V with ±2.5% accuracy over the full -40°C to +105°C operating range. This specification is guaranteed by design-not just typical-and ensures consistent brownout detection across industrial environments without requiring recalibration or external compensation networks.

Does MXD1817UR31+T support manual reset functionality via an external pushbutton?

No, MXD1817UR31+T does not include manual reset detection. That feature is exclusive to MXD1813/MXD1818 variants. MXD1817UR31+T provides only power-supply monitoring and automatic reset assertion; external reset initiation requires separate circuitry or a different device variant.

What output configuration does MXD1817UR31+T use, and why does it matter for my microprocessor interface?

MXD1817UR31+T uses an active-high push-pull RESET output. This means it actively drives the RESET line high during assertion and sinks current when deasserted-eliminating the need for an external pullup resistor. It's essential for interfacing with μPs that require active-high reset signals (e.g., certain ARM and RISC-V cores), unlike open-drain alternatives that mandate external biasing.

Can MXD1817UR31+T operate reliably when the supply voltage drops below 2.0V?

Yes, MXD1817UR31+T is guaranteed to maintain correct RESET/RESET logic state down to VCC = +1.0V. This allows it to assert reset cleanly even during deep brownout conditions-such as failing batteries or severe load transients-ensuring the connected microprocessor remains held in reset until power is fully restored.

Is MXD1817UR31+T pin-compatible with other devices in the MXD181x family?

MXD1817UR31+T shares the same SOT23-3 pinout (VCC–RESET–GND) with all MXD181x variants in the U-suffix package, including MXD1810–MXD1813 and MXD1815–MXD1818. However, output polarity (active-high vs. active-low) and features (e.g., manual reset) differ-so electrical compatibility requires verification of reset logic level and functional requirements, not just pin mapping.