Analog Devices Inc./Maxim Integrated MAX6381XR18D2

Overview

MAX6381XR18D2 from Maxim Integrated is a low-power microprocessor supervisory circuit with factory-set 1.8V reset threshold, 20ms minimum reset timeout, active-low push-pull reset output, and guaranteed operation down to VCC = 1V. It monitors single supply rails in portable electronics and embedded controllers where ultra-low quiescent current (3µA at 1.8V) and precise voltage supervision are critical.

For engineers reviewing the MAX6381XR18D2 datasheet, MAX6381XR18D2 pinout, MAX6381XR18D2 application, or MAX6381XR18D2 equivalent, key selection criteria include reset threshold accuracy (±2.5% over –40°C to +125°C), SC70-3 package compatibility, VCC reset assertion timing under brownout, and manual reset absence in this variant.

Technical Context

The MAX6381XR18D2 implements a precision bandgap-based voltage comparator with ±2.5% threshold accuracy across –40°C to +125°C and 60ppm/°C tempco. Its internal timer generates a fixed 20ms minimum reset timeout after VCC rises above the 1.8V threshold.

No manual reset input or auxiliary RESET IN is present - this is a dedicated single-supply monitor with push-pull active-low reset output that remains valid down to VCC = 1V and supports sink currents up to 3.2mA at VCC ≥ 4.5V.

Key Specifications

Pinout & Package

MAX6381XR18D2 is housed in a 3-pin SC70-3 package (package code X3-2), measuring 2.0mm × 2.1mm × 0.95mm, with gull-wing leads and lead-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TRD2+T, MAX6381XR18D2 delivers tighter threshold accuracy and lower ICC for extended battery life; versus TPS3808G18DBVR, it provides direct-drive push-pull output eliminating BOM components and layout overhead.

Availability

MAX6381XR18D2 is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, automotive body control units, and wearable health monitors requiring stable component supply with long-term lifecycle support.

Supply support for MAX6381XR18D2 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 power, sensing, and interface applications in industrial, automotive, and computing markets.

The MAX6381–MAX6390 family delivers ultra-low-power, high-accuracy voltage supervision for microprocessor-based systems where reliability under brownout and minimal quiescent current are essential design requirements.

FAQ

What is the exact reset threshold voltage of MAX6381XR18D2 and how tightly is it specified?

The MAX6381XR18D2 has a factory-set nominal reset threshold of 1.8V, with guaranteed accuracy of ±2.5% over the full operating temperature range of –40°C to +125°C. This means the actual trip point falls between 1.755V and 1.845V under all conditions, ensuring robust power-on reset for 1.8V logic domains without external trimming. The MAX6381XR18D2 achieves this via laser-trimmed on-chip references and BiCMOS process matching.

Does MAX6381XR18D2 include a manual reset input (MR) pin?

No, the MAX6381XR18D2 does not feature a manual reset input. It is a dedicated single-supply supervisory circuit with only three pins: VCC, GND, and active-low RESET. Manual reset capability is present only in variants such as MAX6384, MAX6385, MAX6386, and MAX6390 - the MAX6381XR18D2 is optimized for simplicity and minimal footprint in applications requiring only VCC monitoring.

What is the minimum supply voltage at which MAX6381XR18D2 guarantees correct reset output logic state?

The MAX6381XR18D2 guarantees valid reset output logic state down to VCC = 1.0V. Below this level, the internal comparator and output driver may become indeterminate. This specification ensures reliable reset assertion during deep brownout events common in battery-powered systems, distinguishing the MAX6381XR18D2 from many competitors that require VCC > 1.5V for guaranteed operation.

What package type and dimensions does MAX6381XR18D2 use?

The MAX6381XR18D2 is supplied in a 3-pin SC70-3 package (package code X3-2), with overall dimensions of 2.0mm × 2.1mm × 0.95mm and gull-wing surface-mount leads. Its compact footprint and low profile make it ideal for space-constrained PCBs in portable and wearable electronics. The device is lead-free and RoHS-compliant.

How does the 20ms reset timeout of MAX6381XR18D2 benefit system-level design?

The 20ms minimum reset timeout of MAX6381XR18D2 ensures the microprocessor remains held in reset long enough for power supplies, clocks, and internal registers to stabilize after VCC exceeds 1.8V - matching typical µP power-up sequences without requiring external timing components. This eliminates design uncertainty around reset duration and avoids premature code execution that could corrupt memory or peripherals. The MAX6381XR18D2 implements this via a precision on-chip RC timer with <±15% variation across temperature and voltage.