Analog Devices Inc./Maxim Integrated MXD1817UR29+

Overview

MXD1817UR29+ from Maxim Integrated is a low-power microprocessor reset supervisor IC designed for +2.5V/+3.0V/+3.3V digital systems. It provides active-high push-pull RESET output, 2.88V factory-set reset threshold (±2.5% over temperature), 100ms minimum reset timeout, and guaranteed operation down to VCC = +1V. It is used in portable battery-powered equipment to ensure reliable μP initialization during power-up, brownout, and manual reset events.

For engineers reviewing the MXD1817UR29+ datasheet, MXD1817UR29+ pinout, MXD1817UR29+ application, or MXD1817UR29+ equivalent, key selection criteria include reset threshold accuracy, active-high push-pull drive capability, manual-reset compatibility (not supported), supply current at 4μA typical, and SOT23-3 package compatibility with space-constrained embedded designs.

Technical Context

The MXD1817UR29+ integrates a precision voltage comparator monitoring VCC against a trimmed 2.88V reference, an internal timer enforcing ≥100ms reset assertion after VCC recovery, and a push-pull output stage capable of sourcing 350μA while asserted. It operates across -40°C to +105°C with no external components required.

Unlike MXD1813/MXD1818 variants, it lacks manual-reset debounce circuitry and open-drain configuration - its RESET pin is strictly active-high push-pull, eliminating need for external pullup resistors and enabling direct interface with μP reset inputs requiring high-valid reset signals.

Key Specifications

Pinout & Package

MXD1817UR29+ is housed in a 3-pin SOT23 package (U3-1 outline) with gull-wing leads, RoHS-compliant lead-free finish (+T suffix), and thermal pad not present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TRD3+T, MXD1817UR29+ offers tighter threshold accuracy (±2.5% vs ±3%) and lower quiescent current (4μA vs 12μA); compared with TPS3808G125DBVR, it eliminates external components and reduces board area but fixes threshold at 2.88V.

Availability

MXD1817UR29+ is available at Aetrix Electronics and suitable for portable medical monitors, industrial PLC I/O modules, smart energy meters, and wireless sensor nodes requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MXD1817UR29+ 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, computing, communications, and consumer applications.

The MXD1810–MXD1818 family was developed specifically to deliver low-cost, space-efficient, single-chip reset supervision for battery-powered and thermally demanding embedded systems using 2.5V/3.0V/3.3V or 5V rails.

FAQ

What is the exact reset threshold voltage of the MXD1817UR29+ and how stable is it over temperature?

The MXD1817UR29+ has a factory-set reset threshold of 2.88V with ±2.5% accuracy over the full operating temperature range of -40°C to +105°C. This specification is guaranteed by design and production-tested per Maxim's datasheet limits. The MXD1817UR29+ uses laser-trimmed on-chip references to maintain stability, and typical normalized threshold variation across temperature is less than ±0.5% relative to room-temperature value.

Does the MXD1817UR29+ support manual reset functionality via the RESET pin?

No, the MXD1817UR29+ does not support manual reset detection. Unlike MXD1813/MXD1818 variants, it lacks internal debouncing circuitry and push-button detect logic. Its RESET pin is strictly an active-high push-pull output driven solely by VCC monitoring - pulling RESET low externally has no effect on device state. For manual reset capability, consider MXD1818UR29+ instead.

What is the maximum sink/source current capability of the MXD1817UR29+ RESET output?

The MXD1817UR29+ RESET output can source up to 350μA when asserted (driving high) and sink up to 10mA when deasserted (driving low), tested at VCC ≥ 2.7V and VOUT = 0.4V. This push-pull drive strength allows direct interfacing with standard CMOS inputs and short PCB traces without external buffering, and exceeds typical μP reset input leakage requirements.

Can the MXD1817UR29+ operate reliably at VCC = +1.2V, and what happens to RESET output below that?

Yes, the MXD1817UR29+ is guaranteed to assert and deassert RESET correctly down to VCC = +1.0V, per datasheet Absolute Maximum Ratings and Electrical Characteristics. Below +1.0V, operation is not specified; RESET output becomes indeterminate due to insufficient headroom for internal comparators and output stage. For applications requiring valid reset down to 0V, a 100kΩ pullup resistor from RESET to VCC is recommended per Maxim Application Note.

Is the MXD1817UR29+ pin-compatible with industry-standard reset supervisors like the MAX809 series?

Yes, the MXD1817UR29+ uses the standard SOT23-3 package (U3-1 outline) with identical pinout (VCC–RESET–GND) and electrical behavior as MAX809TRD3+T and similar active-high push-pull reset ICs. No PCB layout changes are required for drop-in replacement, provided the 2.88V threshold meets system requirements - always verify timing and voltage margins in final design validation.