Analog Devices Inc./Maxim Integrated MAX6386XS31D3+T

Overview

MAX6386XS31D3+T from Maxim Integrated is a low-power microprocessor supervisory circuit with open-drain active-low reset output, factory-set 3.08V reset threshold (±2.5% over –40°C to +125°C), 140ms minimum VCC reset timeout, and debounced manual reset input (MR) with internal 63kΩ pullup. It monitors single supply voltage in battery-powered embedded systems requiring reliable power-on reset and brownout protection.

For engineers reviewing the MAX6386XS31D3+T datasheet, MAX6386XS31D3+T pinout, MAX6386XS31D3+T application, or MAX6386XS31D3+T equivalent, key selection criteria include its 3.08V threshold accuracy, 140ms reset hold time, MR debounce capability, open-drain output compatibility with mixed-voltage logic, and guaranteed valid reset state down to VCC = 1V.

Technical Context

The device implements a precision bandgap-based reset comparator with ±2.5% threshold tolerance across temperature, paired with a digital timeout counter that guarantees minimum 140ms assertion after VCC recovery. Its MR input features internal pullup and 1µs minimum pulse width support, enabling direct connection to momentary switches without external RC networks.

Reset assertion occurs on VCC falling below 3.08V or MR pulled low; deassertion follows only after both conditions clear and the 140ms timer expires. The open-drain RESET output requires an external pullup and sinks up to 3.2mA at VCC ≥ 4.5V with VOL ≤ 0.4V, ensuring interoperability with I²C-bus and other open-drain systems.

Key Specifications

Pinout & Package

MAX6386XS31D3+T is packaged in a RoHS-compliant 4-pin SC70 (package code X4+1, outline 21-0098), measuring 2.0mm × 2.1mm × 0.95mm, suitable for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6386XS31D3+T, MAX809TRD3+T offers simpler drive but no MR, while TPS3808G30DBVR provides longer timeout and TI-specific qualification - MAX6386XS31D3+T uniquely balances MR integration, ultra-low 1.8V current, and precise 3.08V threshold in a 4-pin SC70 package.

Availability

MAX6386XS31D3+T is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, automotive body control units, and smart home hub power management requiring stable component supply and long-term lifecycle support.

Supply support for MAX6386XS31D3+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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and communications applications.

The MAX6381–MAX6390 family was designed specifically for low-voltage, low-power microprocessor supervision in space- and energy-constrained systems, emphasizing precision threshold accuracy, minimal quiescent current, and robust noise immunity.

FAQ

What is the exact reset threshold voltage of MAX6386XS31D3+T and how stable is it over temperature?

The MAX6386XS31D3+T has a factory-set nominal reset threshold of 3.08V, with guaranteed tolerance of ±2.5% over the full operating temperature range of –40°C to +125°C. This stability is achieved through laser-trimmed bandgap references and validated by production testing per the datasheet's Electrical Characteristics table. The MAX6386XS31D3+T maintains this accuracy without external calibration or compensation components.

Does MAX6386XS31D3+T support manual reset, and what are the electrical requirements for the MR pin?

Yes, MAX6386XS31D3+T includes a debounced manual reset input (MR) with an internal 63kΩ pullup resistor to VCC. To assert reset, MR must be driven below 0.3×VCC (for VTH < 4V) for ≥1µs. The pin accepts TTL/CMOS logic levels and open-drain signals. No external components are required - the MAX6386XS31D3+T handles debouncing internally, making it ideal for direct pushbutton interfacing.

What is the function of the open-drain RESET output in MAX6386XS31D3+T, and what pullup value is recommended?

The open-drain RESET output in MAX6386XS31D3+T allows wired-OR connection with other reset sources and level translation across voltage domains. It sinks up to 3.2mA at VCC ≥ 4.5V with VOL ≤ 0.4V. A 10kΩ pullup to the target logic rail (e.g., 3.3V) is typical; values from 4.7kΩ to 100kΩ are acceptable depending on rise time and bus capacitance. The MAX6386XS31D3+T does not include an internal pullup.

Can MAX6386XS31D3+T operate reliably during deep brownout conditions?

Yes, MAX6386XS31D3+T guarantees correct reset output state down to VCC = 1.0V, ensuring the RESET signal remains asserted and logically valid even as the supply collapses. This behavior is specified in the Electrical Characteristics table and verified across temperature. Unlike push-pull supervisors, the open-drain output of MAX6386XS31D3+T requires an external pullup to maintain high state above VCC, but assertion (low) remains robust down to 1V.

Is MAX6386XS31D3+T pin-compatible with other members of the MAX6381–MAX6390 family?

MAX6386XS31D3+T uses the 4-pin SC70 package shared with MAX6384, MAX6385, MAX6387–MAX6390 in XS-prefix variants, and is pin-compatible within that group (VCC, RESET, MR, GND). However, it is not pin-compatible with 3-pin SC70 (MAX6381–MAX6383) or 6-pin μDFN versions. Always verify pin mapping against the "Pin Configurations" section of the MAX6386XS31D3+T datasheet before board reuse.