Analog Devices Inc./Maxim Integrated MAX6381XR31D3

Overview

MAX6381XR31D3 from Maxim Integrated is a low-power microprocessor supervisory circuit with factory-set 3.08V 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 battery-powered embedded systems and asserts reset during brownout or power-up sequencing. Designed for space-constrained applications, it consumes only 3µA at +1.8V.

For engineers reviewing the MAX6381XR31D3 datasheet, MAX6381XR31D3 pinout, MAX6381XR31D3 application, or MAX6381XR31D3 equivalent, key selection criteria include its precise ±2.5% threshold accuracy over –40°C to +125°C, guaranteed valid reset state at VCC ≥ 1V, immunity to negative-going VCC transients, SC70-3 package footprint, and compatibility with manual reset–free designs requiring minimal quiescent current.

Technical Context

The MAX6381XR31D3 implements a precision bandgap-based voltage comparator with internal 1.27V reference for threshold detection and a temperature-compensated RC timer for deterministic reset timeout. Its open-drain RESET output requires an external pullup and remains asserted low until VCC exceeds 3.08V and sustains for ≥140ms.

No manual reset (MR) input or auxiliary RESET IN functionality is integrated - this variant is optimized for single-supply monitoring with minimal external components and no user-initiated reset capability. The device operates across full industrial temperature range without requiring external timing capacitors or resistors.

Key Specifications

Pinout & Package

MAX6381XR31D3 is housed in a 3-pin SC70-3 package (package code X3-2), measuring 2.0mm × 2.1mm × 0.95mm, with exposed pad option not applicable. 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 and TPS3808G33DBVR, the MAX6381XR31D3 uniquely balances precise 3.08V threshold alignment with open-drain versatility and industry-leading transient immunity - making it optimal for 3.0V–3.3V systems where reset bus sharing or noise resilience is required.

Availability

MAX6381XR31D3 is available at Aetrix Electronics and suitable for battery-powered IoT sensors, industrial PLC I/O modules, automotive body control units, and medical wearable monitors requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6381XR31D3 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, emphasizing low power, small size, and high reliability.

The MAX6381–MAX6390 family delivers single/dual low-voltage supervisory circuits targeting space- and power-constrained embedded systems where deterministic reset behavior and thermal stability are non-negotiable.

FAQ

What is the exact reset threshold voltage of the MAX6381XR31D3?

The MAX6381XR31D3 has a factory-set nominal reset threshold of 3.08V, with guaranteed limits of 3.00V (min) and 3.15V (max) over the full operating temperature range of –40°C to +125°C. This value is laser-trimmed during production and does not require external adjustment. The MAX6381XR31D3 achieves ±2.5% accuracy across temperature, confirmed by production testing per Maxim's datasheet specifications.

Does the MAX6381XR31D3 include a manual reset input (MR)?

No, the MAX6381XR31D3 does not feature a manual reset input. It belongs to the MAX6381/MAX6382/MAX6383 subgroup, which lacks MR functionality. Only MAX6384–MAX6386 and MAX6390 variants include MR. The MAX6381XR31D3 is designed exclusively for automatic VCC monitoring and reset assertion, simplifying layout and reducing component count in applications where user-initiated reset is unnecessary.

What package type and dimensions does the MAX6381XR31D3 use?

The MAX6381XR31D3 is supplied in a 3-pin SC70-3 package (package code X3-2), with body dimensions of 2.0mm × 2.1mm × 0.95mm and a lead pitch of 0.65mm. It has no exposed thermal pad. This ultra-small outline enables high-density placement in wearables and miniature sensors, and is compatible with standard SC70 reflow profiles per JEDEC J-STD-020.

Can the MAX6381XR31D3 operate reliably below 1.8V supply voltage?

Yes, the MAX6381XR31D3 is fully specified to operate from VCC = 1.0V to 5.5V. Its reset output remains valid and correctly asserted/deasserted down to VCC = 1.0V, and supply current drops to ~2.5µA at 1.5V. This capability ensures robust brownout protection in Li-ion/LiPo systems experiencing deep discharge or cold-temperature voltage sag, where many competing reset ICs cease functional operation.

Is the MAX6381XR31D3 pin-compatible with other members of the MAX6381–MAX6390 family?

The MAX6381XR31D3 shares the same 3-pin SC70-3 pinout with MAX6381LTxxDx, MAX6382XRxxDx, and MAX6383XRxxDx variants, but is not pin-compatible with 4-pin SC70 or 6-pin µDFN versions (e.g., MAX6384–MAX6390). All SC70-3 variants use identical Pin 1 (RESET), Pin 2 (VCC), Pin 3 (GND) assignment - enabling direct substitution within the same package format when threshold and timeout match design requirements.