Analog Devices Inc./Maxim Integrated MAX6385XS27D4-T

Overview

MAX6385XS27D4-T from Maxim Integrated is a push-pull active-high microprocessor supervisory circuit with factory-set 2.70V reset threshold, 1120ms VCC reset timeout, and manual reset input. It monitors +1.8V to +5.0V supply rails, consumes only 3μA at +1.8V, guarantees valid reset output down to VCC = 1V, and operates across -40°C to +125°C for industrial and automotive power monitoring.

For engineers reviewing the MAX6385XS27D4-T datasheet, MAX6385XS27D4-T pinout, MAX6385XS27D4-T application, or MAX6385XS27D4-T equivalent, key selection criteria include its active-high push-pull reset output, 2.70V ±2.5% threshold accuracy over temperature, 1120ms minimum VCC reset timeout, manual reset debounce capability, and 4-pin SC70 package compatibility with space-constrained embedded systems.

Technical Context

The MAX6385XS27D4-T implements a precision voltage comparator with internal 2.70V reference and ±2.5% threshold accuracy over -40°C to +125°C, paired with a monolithic timer generating a guaranteed-minimum 1120ms reset assertion after VCC recovery. Its MR input features an internal 63kΩ pullup resistor and supports TTL/CMOS logic levels.

This device uses BiCMOS process technology to achieve ultra-low quiescent current (3μA at +1.8V) while maintaining robust negative-going VCC transient immunity and guaranteed reset state validity down to VCC = 1V - enabling reliable brownout detection in battery-powered and low-voltage microcontroller systems.

Key Specifications

Pinout & Package

MAX6385XS27D4-T is housed in a RoHS-compliant 4-pin SC70 package (outline 21-0098), measuring 2.0mm × 2.1mm × 0.95mm, with thermal resistance θ_JA = 322.6°C/W on multilayer board.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6385XS27D4-T, the MAX6385LT27D4-T offers identical functionality in a thermally superior but larger package, while the MAX6326XR27D4-T trades 0.5% threshold accuracy and 2μA higher quiescent current for potential cost savings in non-critical applications.

Availability

MAX6385XS27D4-T is available at Aetrix Electronics and suitable for industrial PLC power monitoring, automotive body control modules, portable medical sensor hubs, and battery-powered smart meters requiring stable component supply with guaranteed long-term availability.

Supply support for MAX6385XS27D4-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 industrial, automotive, communications, and computing markets, with emphasis on low-power, high-reliability solutions.

The MAX6381–MAX6390 family delivers single/dual low-voltage microprocessor supervisory circuits optimized for ultra-low quiescent current, wide temperature operation, and compact packaging in SC70 and μDFN formats.

FAQ

What is the exact reset threshold voltage of the MAX6385XS27D4-T and how stable is it over temperature?

The MAX6385XS27D4-T has a factory-set nominal reset threshold of 2.70V, with guaranteed accuracy of ±2.5% over the full operating temperature range of -40°C to +125°C. This stability is achieved through laser-trimmed internal references and BiCMOS process optimization, ensuring reliable brownout detection without external calibration. The MAX6385XS27D4-T maintains this specification across all production lots and environmental conditions specified in the datasheet.

Does the MAX6385XS27D4-T require an external pullup resistor on its RESET output?

No, the MAX6385XS27D4-T features an active-high push-pull RESET output that actively drives high during reset assertion and sinks current when deasserted. This eliminates the need for an external pullup resistor, simplifying schematic design and reducing component count. The output remains valid down to VCC = 1V, ensuring correct logic levels even during deep brownout conditions. This characteristic is inherent to the MAX6385XS27D4-T's internal driver architecture.

What is the function and electrical behavior of the MR pin on the MAX6385XS27D4-T?

The MR (Manual Reset) pin on the MAX6385XS27D4-T is an active-low input that forces a reset when pulled below 0.3×VCC. It includes an internal 63kΩ pullup resistor to VCC, allowing direct connection of a momentary switch to ground without external components. The MAX6385XS27D4-T guarantees MR glitch rejection of 100ns and supports TTL/CMOS logic levels. MR assertion holds reset active for the full 1120ms timeout period after release, matching the VCC reset timing.

Can the MAX6385XS27D4-T monitor a second voltage rail like V_CORE or V_I/O?

No, the MAX6385XS27D4-T monitors only the VCC supply rail and does not include an auxiliary RESET IN input. That feature is reserved for the MAX6387/MAX6388/MAX6389 variants. The MAX6385XS27D4-T is a single-supply supervisor with dedicated MR input and active-high push-pull output. For dual-rail monitoring, designers must select a different member of the MAX6381–MAX6390 family such as MAX6387XS27D4-T, which adds the RESET IN comparator referenced to +1.27V.

What package type and dimensions does the MAX6385XS27D4-T use, and is it RoHS-compliant?

The MAX6385XS27D4-T uses a 4-pin SC70 package (outline number 21-0098) measuring 2.0mm × 2.1mm × 0.95mm, with land pattern number 90-0187. The "+T" suffix confirms it is lead(Pb)-free and RoHS-compliant. Thermal resistance is θ_JA = 322.6°C/W on a multilayer board. This compact package enables high-density placement in space-constrained applications such as wearables and automotive ECUs, and the MAX6385XS27D4-T meets all applicable environmental compliance requirements.