Analog Devices Inc./Maxim Integrated MAX6381XR44D3+T

Overview

MAX6381XR44D3+T from Maxim Integrated is a low-power microprocessor supervisory circuit in 3-pin SC70 package, featuring a factory-set 4.38V reset threshold (±2.5% over -40°C to +125°C), 140ms minimum VCC reset timeout, and active-low push-pull reset output. It monitors single supply voltage down to 1.0V, consumes only 3μA at 1.8V, and guarantees valid reset state during brownout - used in portable battery-powered equipment requiring reliable power-on reset.

For engineers reviewing the MAX6381XR44D3+T datasheet, MAX6381XR44D3+T pinout, MAX6381XR44D3+T application, or MAX6381XR44D3+T equivalent, key selection criteria include reset threshold accuracy, ultra-low quiescent current, guaranteed operation down to VCC = 1V, compatibility with 1.8V–5.5V systems, and SC70 footprint constraints for space-constrained designs.

Technical Context

The device implements a precision bandgap-based voltage comparator with ±2.5% threshold accuracy across temperature, coupled to a monolithic RC timer for deterministic 140ms reset assertion after VCC recovery. Its push-pull output drives directly into μP reset inputs without external pullup, and internal logic ensures reset remains asserted during VCC transients below 4.38V until timeout expires.

No manual reset (MR) or auxiliary RESET IN input is present - this variant is optimized for single-supply monitoring only, distinguishing it from MAX6384–MAX6390 (MR-enabled) and MAX6387–MAX6389 (dual-monitor) families. The 3-pin SC70 configuration eliminates unused terminals, reducing board area and parasitic capacitance.

Key Specifications

Pinout & Package

Package: 3-pin SC70 (outline 21-0075, land pattern 90-0208), footprint-compatible with industry-standard low-pin-count supervisory ICs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TRD3+T and TPS3808G33DBVR, MAX6381XR44D3+T delivers optimal balance of ultra-low 3μA supply current, precise 140ms timeout matching common processor requirements, and push-pull output eliminating external components - making it ideal for new designs prioritizing size, power, and simplicity.

Availability

MAX6381XR44D3+T is available at Aetrix Electronics and suitable for portable/battery-powered equipment, critical μP and μC power monitoring, and computers requiring stable component supply with automotive-grade (-40°C to +125°C) temperature performance.

Supply support for MAX6381XR44D3+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 demanding industrial, automotive, and computing applications.

The MAX6381–MAX6390 family delivers low-power, high-accuracy voltage supervision in miniature packages - engineered specifically for space- and power-constrained microprocessor systems needing guaranteed reset behavior across wide temperature ranges.

FAQ

What is the exact reset threshold voltage of MAX6381XR44D3+T and how stable is it over temperature?

The MAX6381XR44D3+T has a nominal reset threshold of 4.38V, with a guaranteed range of 4.27V to 4.48V at +25°C and ±2.5% variation over -40°C to +125°C. This stability is achieved via factory laser trimming of an internal bandgap reference, ensuring consistent performance without external calibration. The MAX6381XR44D3+T maintains this accuracy across its full operating temperature range, critical for reliable reset in automotive and industrial environments.

Does MAX6381XR44D3+T support manual reset functionality?

No, MAX6381XR44D3+T does not include a manual reset (MR) input. It is part of the MAX6381/MAX6382/MAX6383 subgroup, which lacks MR and auxiliary RESET IN pins. Manual reset capability is only available in MAX6384–MAX6390 variants (e.g., MAX6384XR44D3+T). The MAX6381XR44D3+T is designed exclusively for automatic VCC monitoring with no user-initiated reset provision.

What is the minimum supply voltage at which MAX6381XR44D3+T guarantees correct reset output behavior?

The MAX6381XR44D3+T guarantees valid reset output logic state down to VCC = 1.0V, as specified in the Absolute Maximum Ratings and Electrical Characteristics tables. Below this level, the internal circuitry may not function reliably. This feature ensures robust reset assertion during deep brownout conditions before complete power collapse - a key reliability advantage of the MAX6381XR44D3+T over supervisors that require ≥1.5V to operate.

Can MAX6381XR44D3+T be used to monitor a 1.8V supply rail?

Yes, MAX6381XR44D3+T can monitor a 1.8V supply, but its 4.38V reset threshold means it will not assert reset for undervoltage on a 1.8V rail. It is intended for monitoring higher-voltage rails such as 3.3V or 5V. To supervise a 1.8V rail, select a variant with appropriate threshold (e.g., MAX6381XR18D3+T, 1.80V threshold). The MAX6381XR44D3+T's VCC operating range (1.0V–5.5V) supports powering from 1.8V while monitoring a separate 3.3V/5V rail.

What package type and pin count does MAX6381XR44D3+T use, and is it RoHS-compliant?

MAX6381XR44D3+T uses the 3-pin SC70 package (outline 21-0075), with pinout: Pin 1 = RESET (active-low push-pull), Pin 2 = VCC, Pin 3 = GND. The "+T" suffix confirms lead(Pb)-free and RoHS-compliant construction per Maxim Integrated's ordering conventions. This compact package measures 2.0mm × 2.1mm × 0.95mm, enabling high-density PCB layouts in portable electronics.