Analog Devices Inc./Maxim Integrated MAX6385XS42D3-T

Overview

MAX6385XS42D3-T from Maxim Integrated is a push-pull active-high microprocessor supervisory circuit with factory-set 4.20V reset threshold, 140ms minimum VCC reset timeout, and manual reset input. It monitors +1.8V to +5.0V supply rails in low-power embedded systems, consumes only 3μA at +1.8V, and guarantees valid reset output down to VCC = 1V. Used in portable equipment and critical μP power sequencing.

For engineers reviewing the MAX6385XS42D3-T datasheet, MAX6385XS42D3-T pinout, MAX6385XS42D3-T application, or MAX6385XS42D3-T equivalent, key selection criteria include its 4.20V ±2.5% threshold accuracy over –40°C to +125°C, 140ms reset timeout, active-high push-pull output, integrated MR pullup (63kΩ), and 4-pin SC70 package compatibility with space-constrained designs.

Technical Context

The MAX6385XS42D3-T implements a precision voltage comparator with internal 4.20V reference and a monostable timer for reset assertion. Its reset logic asserts high when VCC falls below 4.20V or when the manual reset (MR) pin is pulled low, holding the active state for ≥140ms after recovery.

It features an internal 63kΩ pullup on MR, supports VCC operation from 1.0V to 5.5V, and maintains guaranteed reset output validity down to VCC = 1V. The device uses BiCMOS process technology and meets AEC-Q100 requirements for automotive-grade versions (though this variant is standard industrial).

Key Specifications

Pinout & Package

MAX6385XS42D3-T is housed in a RoHS-compliant 4-pin SC70 package (outline 21-0098, land pattern 90-0187), measuring 2.0mm × 2.1mm × 0.95mm, optimized for high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326XR42D3+T and TPS3808G33DBVR, MAX6385XS42D3-T uniquely combines 4.20V precision threshold, active-high push-pull drive, and integrated MR pullup in a 4-pin SC70 - reducing BOM count and layout complexity for new designs targeting 4.2V supply supervision with manual reset.

Availability

MAX6385XS42D3-T is available at Aetrix Electronics and suitable for portable/battery-powered equipment, critical μP and μC power monitoring, and intelligent instruments requiring stable component supply and long-term production continuity.

Supply support for MAX6385XS42D3-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, sensing, and interface applications in industrial, automotive, and computing markets.

The MAX6381–MAX6390 family delivers low-power, factory-trimmed μP supervisory circuits optimized for space-constrained, battery-sensitive systems requiring accurate voltage monitoring and robust reset generation.

FAQ

What is the exact reset threshold voltage of MAX6385XS42D3-T and how stable is it over temperature?

The MAX6385XS42D3-T has a factory-set nominal reset threshold of 4.20V, 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 matching, ensuring consistent brownout detection without external calibration. The MAX6385XS42D3-T maintains this tolerance across all production lots and lifetime stress conditions.

Does MAX6385XS42D3-T require an external pullup resistor on its RESET pin?

No, MAX6385XS42D3-T does not require an external pullup resistor on its RESET pin because it features an active-high push-pull output stage. The internal driver actively pulls the RESET line high during assertion and sinks current to pull it low when deasserted. This eliminates the need for external biasing components and ensures clean, rail-to-rail logic transitions compatible with standard CMOS and TTL inputs.

What is the function and electrical behavior of the MR pin on MAX6385XS42D3-T?

The MR (Manual Reset) pin on MAX6385XS42D3-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 it to remain unconnected if unused. MR accepts TTL/CMOS logic levels and supports momentary switch interfacing directly to GND. The MAX6385XS42D3-T guarantees MR-to-RESET delay of ≤200ns and rejects glitches <100ns, enabling noise-immune manual reset in industrial environments.

Can MAX6385XS42D3-T operate reliably when VCC drops below 1.8V?

Yes, MAX6385XS42D3-T is fully specified to operate down to VCC = 1.0V and guarantees valid RESET output state (logic high during assertion) even at 1.0V supply. Its internal bandgap reference and comparator remain functional at sub-1.8V levels, and the push-pull output maintains defined voltage levels (VOH ≥ 0.8×VCC, VOL ≤ 0.3V) down to 1.0V. This ensures fail-safe reset assertion during deep brownout conditions before system collapse.

What package type and dimensions does MAX6385XS42D3-T use, and is it RoHS-compliant?

MAX6385XS42D3-T uses a 4-pin SC70 package (outline 21-0098) measuring 2.0mm × 2.1mm × 0.95mm with gull-wing leads. The "+T" suffix confirms it is lead(Pb)-free and RoHS-compliant. This compact footprint supports high-density PCB layouts in portable and wearable electronics, and its thermal resistance (θJA = 322.6°C/W on multilayer board) enables operation in thermally constrained enclosures without heatsinking.