Analog Devices Inc./Maxim Integrated MAX6381XR29D2+

Overview

MAX6381XR29D2+ from Maxim Integrated is a low-power microprocessor supervisory circuit in a 3-pin SC70 package, featuring a factory-set 2.93V reset threshold (±2.5% over -40°C to +125°C), 20ms minimum reset timeout, and active-low push-pull reset output. It monitors VCC from +1.8V to +5.0V while consuming only 3μA at +1.8V, and guarantees valid reset state down to VCC = 1V - ideal for battery-powered embedded controllers requiring reliable power-on reset.

For engineers reviewing the MAX6381XR29D2+ datasheet, MAX6381XR29D2+ pinout, MAX6381XR29D2+ application, or MAX6381XR29D2+ equivalent, key selection considerations include its fixed 2.93V threshold accuracy, 20ms timeout timing, SC70 footprint compatibility with legacy MAX809/MAX810, and guaranteed operation across automotive temperature range (-40°C to +125°C).

Technical Context

The MAX6381XR29D2+ implements a precision bandgap-based voltage comparator with ±2.5% threshold tolerance over full temperature range and 60ppm/°C tempco, paired with a monolithic RC timer for deterministic 20ms reset assertion after VCC recovery. Its push-pull active-low RESET output drives directly into μP reset inputs without external pullup.

No manual reset (MR) or auxiliary RESET IN inputs are included - this variant belongs to the base MAX6381 series, distinguishing it from MR-equipped MAX6384–MAX6386 or dual-monitor MAX6387–MAX6389 families. Reset assertion occurs on VCC falling below 2.93V and remains asserted for ≥20ms after VCC rises above threshold.

Key Specifications

Pinout & Package

3-pin SC70 package (Outline Number 21-0075, Land Pattern 90-0208), surface-mount, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TRD2+T, MAX6381XR29D2+ adds automotive temperature range and tighter tempco; versus TPS3808G18DBVR, it offers lower power and simpler push-pull interface at the cost of no enable functionality.

Availability

MAX6381XR29D2+ is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, portable medical sensor hubs, and battery-powered smart meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6381XR29D2+ 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, with emphasis on low-power, high-reliability solutions.

The MAX6381–MAX6390 family delivers single-supply voltage supervision with factory-trimmed thresholds and configurable timeouts, targeting space-constrained, battery-sensitive, and automotive-grade embedded systems requiring guaranteed reset behavior.

FAQ

What is the exact reset threshold voltage of the MAX6381XR29D2+ and how stable is it over temperature?

The MAX6381XR29D2+ has a nominal reset threshold of 2.93V, with guaranteed tolerance of ±2.5% over the full operating temperature range of -40°C to +125°C. Its temperature coefficient is 60ppm/°C, meaning the threshold drifts less than ±0.3% across the entire range - critical for automotive and industrial applications where ambient temperature varies widely. This specification is confirmed in the Electrical Characteristics table of the official datasheet.

Does the MAX6381XR29D2+ include a manual reset input (MR) pin?

No, the MAX6381XR29D2+ does not include a manual reset input. It belongs to the base MAX6381 series, which features only VCC monitoring and a push-pull active-low RESET output. Manual reset capability is present only in variants like MAX6384, MAX6385, MAX6386, and MAX6390 - all of which use 4-pin SC70 or 6-pin μDFN packages. The MAX6381XR29D2+ uses a 3-pin SC70 and has no MR pin.

What is the minimum VCC voltage at which the MAX6381XR29D2+ guarantees correct RESET output logic state?

The MAX6381XR29D2+ guarantees that its RESET output remains in a valid logic state down to VCC = 1.0V. Below this voltage, the internal circuitry may not sustain correct output levels. This feature ensures reliable reset assertion during deep brownout conditions - a key requirement for battery-backed systems and automotive applications where supply collapse is possible. This is explicitly specified in the Absolute Maximum Ratings and Electrical Characteristics sections.

Is the MAX6381XR29D2+ pin-compatible with older Maxim reset ICs like the MAX809?

Yes, the MAX6381XR29D2+ is pin-compatible with the MAX809 series in the 3-pin SC70 package. Both share identical pinout: Pin 1 = RESET (active-low push-pull), Pin 2 = VCC, Pin 3 = GND. However, MAX6381XR29D2+ extends the temperature range to -40°C to +125°C (AEC-Q100 qualified) and improves threshold accuracy stability versus the industrial-grade MAX809. No PCB changes are required for drop-in replacement in existing SC70 layouts.

What package type and dimensions does the MAX6381XR29D2+ use, and what land pattern is recommended?

The MAX6381XR29D2+ uses the 3-pin SC70 package (Outline Number 21-0075, Package Code X3+2), measuring 1.25mm × 0.85mm with 0.65mm pitch. The recommended land pattern is Maxim's Land Pattern Number 90-0208, optimized for reflow soldering on multilayer PCBs. Thermal resistance θJA is 340.4°C/W on a standard four-layer board - design guidelines are published in Maxim's thermal tutorial documentation.