Analog Devices Inc./Maxim Integrated MAX6381XR29D3

Overview

The MAX6381XR29D3 from Maxim Integrated is a low-power microprocessor supervisory circuit with factory-set 2.93V reset threshold, 140ms minimum reset timeout, active-low open-drain reset output, and operation down to VCC = 1.0V. It monitors single supply voltage in portable electronics and embedded controllers, consuming only 3µA at +1.8V and offering ±2.5% threshold accuracy over -40°C to +125°C.

For engineers reviewing the MAX6381XR29D3 datasheet, MAX6381XR29D3 pinout, MAX6381XR29D3 application, or MAX6381XR29D3 equivalent, key selection criteria include its SC70-3 package, guaranteed reset assertion down to 1V VCC, immunity to negative-going VCC transients, and compatibility with battery-powered systems requiring ultra-low quiescent current.

Technical Context

This device implements a precision bandgap-based voltage comparator with internal 1.27V reference for threshold detection and a temperature-compensated RC timer for reset timeout generation. The open-drain RESET output requires an external pull-up resistor and asserts low when VCC falls below 2.93V (min), remaining asserted for ≥140ms after VCC recovers.

No manual reset (MR) or auxiliary RESET IN inputs are present - the MAX6381XR29D3 is a minimal-function variant optimized for space-constrained single-supply monitoring. Its BiCMOS process ensures stable operation across automotive-grade temperature range (-40°C to +125°C) with 60ppm/°C reset threshold tempco.

Key Specifications

Pinout & Package

MAX6381XR29D3 uses the 3-pin SC70-3 package (package code X3-2), measuring 2.0mm × 2.1mm × 0.95mm with gull-wing leads. Pin 1 = RESET (active-low open-drain), Pin 2 = VCC, Pin 3 = GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TRD3+T and TPS3808G33DBVR, the MAX6381XR29D3 provides the smallest footprint (SC70-3), lowest ICC among open-drain variants, and optimal balance of timing, accuracy, and thermal robustness for space- and power-constrained designs without manual reset needs.

Availability

MAX6381XR29D3 is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, automotive body control units, and smart energy meters requiring stable component supply with long-term lifecycle support.

Supply support for MAX6381XR29D3 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 communications applications.

The MAX6381–MAX6390 family delivers ultra-low-power, high-accuracy reset supervision for battery-operated and thermally harsh systems where reliability and minimal board area are critical.

FAQ

What is the exact reset threshold voltage range for MAX6381XR29D3?

The MAX6381XR29D3 has a factory-set reset threshold of 2.93V (minimum), 3.00V (nominal), and 3.08V (maximum) over the full temperature range of -40°C to +125°C. This 2.93V min threshold ensures reliable detection of brownout conditions in +3.3V systems while maintaining margin against noise-induced false triggers. The ±2.5% accuracy is guaranteed across temperature without calibration.

Does MAX6381XR29D3 support manual reset functionality?

No, the MAX6381XR29D3 does not include a manual reset (MR) input. It is a dedicated single-supply supervisor with only RESET, VCC, and GND pins. Manual reset capability is present only in MAX6384–MAX6386 and MAX6390 variants. For designs requiring MR, consider MAX6390XS29D4 or MAX6384XS29D3 instead - both share the same 2.93V threshold and SC70-4 package.

What package type and dimensions does MAX6381XR29D3 use?

MAX6381XR29D3 uses the 3-pin SC70-3 package (package code X3-2), with nominal dimensions of 2.0mm × 2.1mm × 0.95mm and gull-wing lead form. It is RoHS-compliant and lead-free. This compact outline occupies ~40% less board area than standard SOT-23-3 packages, making it ideal for wearables and miniaturized IoT endpoints where space is constrained.

Can MAX6381XR29D3 operate reliably below 1.8V supply?

Yes, MAX6381XR29D3 is fully specified from VCC = 1.0V to 5.5V. At 1.0V, it guarantees correct RESET output logic state and valid reset assertion - critical for systems recovering from deep brownout. Its 3µA supply current at 1.8V scales downward at lower voltages, enabling operation in energy-harvesting applications powered by weak sources such as piezoelectric or thermoelectric generators.

Is an external pull-up resistor required for MAX6381XR29D3's RESET output?

Yes, an external pull-up resistor is mandatory because MAX6381XR29D3 features an open-drain active-low RESET output. A typical value is 10kΩ to 100kΩ connected between RESET and the monitored supply (e.g., 3.3V). This configuration allows wired-OR connection with other reset sources and supports level translation to different logic families. Without the pull-up, RESET remains floating and cannot drive a valid high level.