Analog Devices Inc./Maxim Integrated MAX6381XR29D4+T

Overview

MAX6381XR29D4+T from Maxim Integrated is a low-power microprocessor supervisory circuit with factory-set 2.93V reset threshold, 1120ms V_CC reset timeout, and active-low open-drain reset output in a 3-pin SC70 package. It monitors +1.8V to +5.0V supply rails, consumes only 3μA at +1.8V, guarantees valid reset state down to V_CC = 1V, and targets brownout protection in portable battery-powered systems.

For engineers reviewing the MAX6381XR29D4+T datasheet, MAX6381XR29D4+T pinout, MAX6381XR29D4+T application, or MAX6381XR29D4+T equivalent, key selection considerations include its ±2.5% reset threshold accuracy over –40°C to +125°C, immunity to negative-going V_CC transients, compatibility with dual-voltage monitoring architectures, and RoHS-compliant lead-free packaging.

Technical Context

The MAX6381XR29D4+T implements a precision voltage comparator with internal 2.93V reference and a monostable timer for reset assertion. Its open-drain RESET output requires an external pullup resistor and remains asserted for ≥1120ms after V_CC rises above 2.93V, ensuring μP initialization stability during power-up sequencing.

This device belongs to the MAX6381–MAX6390 family of single-supply supervisors with no manual reset (MR) or auxiliary RESET IN inputs-confirmed by part number decoding (XR = 3-pin SC70, 29 = 2.93V threshold, D4 = 1120ms timeout) and pin configuration tables showing only RESET, V_CC, and GND terminals.

Key Specifications

Pinout & Package

MAX6381XR29D4+T uses a 3-pin SC70 package (outline 21-0075, land pattern 90-0208) with exposed pad not electrically connected. Pin 1 is RESET (active-low open-drain), Pin 2 is V_CC, and Pin 3 is GND - confirmed by "Pin Configurations" diagram on page 9 and "Pin Description" table on page 6 of the datasheet.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6381XR29D4+T, MAX6326XR29D4+T simplifies BOM by removing the pullup resistor but increases leakage risk in high-impedance reset networks, while TPS3808G33DBVR offers superior current efficiency above 2.5V but requires PCB redesign due to 5-pin SOT-23 footprint and adds unused MR functionality.

Availability

MAX6381XR29D4+T is available at Aetrix Electronics and suitable for portable medical sensors, battery-powered data loggers, industrial PLC I/O modules, and automotive body control units requiring stable component supply with guaranteed long-term availability.

Supply support for MAX6381XR29D4+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 power management, sensing, and connectivity applications, serving industrial, automotive, and computing markets.

MAX6381XR29D4+T belongs to the MAX6381–MAX6390 family of low-power μP supervisors engineered specifically for reliable power-on reset and brownout protection in space- and energy-constrained embedded systems.

FAQ

What is the exact reset threshold voltage of MAX6381XR29D4+T?

The MAX6381XR29D4+T has a factory-set nominal reset threshold voltage of 2.93V, with guaranteed tolerance of ±2.5% over the full operating temperature range of –40°C to +125°C. This value is confirmed by the "Reset Thresholds" table on page 7 of the datasheet, where suffix "29" corresponds to V_TH(nom) = 2.93V, V_TH(min) = 2.85V, and V_TH(max) = 3.00V. The MAX6381XR29D4+T uses this fixed threshold without external adjustment components.

Does MAX6381XR29D4+T include a manual reset input (MR)?

No, MAX6381XR29D4+T does not feature a manual reset input. Per the "Selector Guide" on page 9 and "Pin Configurations" on page 10, only MAX6384/MAX6385/MAX6386/MAX6390 variants include MR functionality. The MAX6381XR29D4+T is a 3-pin device with RESET, V_CC, and GND terminals only - confirmed by its pinout diagram and absence of MR in the "Features" list applicable to MAX6381.

What is the function of the RESET pin on MAX6381XR29D4+T?

The RESET pin on MAX6381XR29D4+T is an active-low open-drain output. It pulls low when V_CC falls below 2.93V and remains low for ≥1120ms after V_CC rises above the threshold. Because it is open-drain, an external pullup resistor is required to establish a defined high state. This configuration enables wired-OR reset bus topologies and compatibility with mixed-voltage systems - all explicitly documented in the "Pin Description" section for MAX6381 on page 6.

What package type and dimensions does MAX6381XR29D4+T use?

MAX6381XR29D4+T uses a 3-pin SC70 package (outline number 21-0075, land pattern 90-0208) measuring 1.25mm × 0.8mm with 0.65mm pitch. This information is specified in the "Ordering Information" table on page 1 and verified by the "Package Information" section on page 2. The package code "X3+2" denotes the RoHS-compliant SC70 variant, and the "+T" suffix confirms tape-and-reel packaging.

Is MAX6381XR29D4+T qualified for automotive applications?

The base MAX6381XR29D4+T is not automotive-qualified; however, the /V variant (e.g., MAX6381XR29D4/V+T) is AEC-Q100 qualified for automotive use. As stated in the "Features" section on page 1, AEC-Q100 qualification applies only to parts with the "/V" suffix in the ordering code. The MAX6381XR29D4+T lacks this suffix and is rated for –40°C to +125°C operation but does not carry formal automotive qualification documentation.