Analog Devices Inc./Maxim Integrated MAX6385XS26D3+T

Overview

MAX6385XS26D3+T from Maxim Integrated is a push-pull active-high microprocessor supervisory circuit with factory-set 2.63V reset threshold, 140ms minimum VCC reset timeout, and manual reset input. It monitors +1.8V to +5.0V supply rails, consumes only 3μA at +1.8V, and guarantees valid reset output down to VCC = 1V. Used in battery-powered controllers and portable instrumentation for reliable power-up/brownout protection.

For engineers reviewing the MAX6385XS26D3+T datasheet, MAX6385XS26D3+T pinout, MAX6385XS26D3+T application, or MAX6385XS26D3+T equivalent, key selection criteria include reset threshold accuracy (±2.5% over –40°C to +125°C), MR input pullup resistance (63kΩ), SC70-4 package footprint, and compatibility with dual-voltage monitoring systems requiring guaranteed reset assertion during low-VCC conditions.

Technical Context

The MAX6385XS26D3+T implements a precision bandgap-based voltage comparator with ±2.5% threshold accuracy across –40°C to +125°C, paired with a temperature-stable RC timer for 140ms minimum reset timeout. Its active-high push-pull RESET output drives high during fault conditions and deasserts cleanly after timeout, eliminating external pullup requirements.

It features a debounced manual reset input (MR) with internal 63kΩ pullup resistor referenced to VCC, supporting TTL/CMOS logic levels and momentary switch interfaces without external components. The device operates from 1.0V to 5.5V supply and maintains correct RESET logic state down to VCC = 1V.

Key Specifications

Pinout & Package

MAX6385XS26D3+T is housed in a RoHS-compliant 4-pin SC70 package (outline 21-0098, land pattern 90-0187), optimized for high-density PCB layouts and reflow-compatible assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6385XS26D3+T, the /V+T variant adds automotive qualification without altering timing or threshold behavior, while TPS3808G33DBVR trades MR capability and push-pull output for tighter threshold accuracy and broader supply range-making it suitable for non-manual-reset industrial applications demanding higher precision.

Availability

MAX6385XS26D3+T is available at Aetrix Electronics and suitable for portable instrumentation, industrial controllers, medical sensors, and dual-voltage embedded systems requiring stable component supply with guaranteed long-term availability.

Supply support for MAX6385XS26D3+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 is a semiconductor company specializing in analog and mixed-signal ICs for power, sensing, interface, and timing applications, now part of Analog Devices.

The MAX6381–MAX6390 family delivers ultra-low-power, precision reset supervision for battery-critical and automotive systems, designed specifically for reliable operation in harsh thermal environments and space-constrained portable electronics.

FAQ

What is the exact reset threshold voltage of MAX6385XS26D3+T and how stable is it over temperature?

The MAX6385XS26D3+T has a factory-set nominal reset threshold of 2.63V, with guaranteed accuracy of ±2.5% over the full –40°C to +125°C operating range. This stability is achieved through laser-trimmed bandgap references and low-drift comparator design, ensuring consistent brownout detection across automotive and industrial thermal profiles. The MAX6385XS26D3+T maintains this specification without requiring external calibration.

Does MAX6385XS26D3+T support manual reset functionality, and what are the electrical requirements for the MR pin?

Yes, MAX6385XS26D3+T includes a debounced manual reset input (MR) with an internal 63kΩ pullup resistor to VCC. The MR pin is active-low and accepts standard TTL/CMOS logic levels: VIH ≥ 0.7×VCC and VIL ≤ 0.3×VCC for VTH < 4V. A normally open momentary switch connected between MR and GND provides full manual reset capability without external components. The MAX6385XS26D3+T guarantees MR-to-RESET delay of 200ns maximum.

What package type and footprint does MAX6385XS26D3+T use, and is it compatible with standard reflow processes?

MAX6385XS26D3+T uses a 4-pin SC70 package (outline 21-0098, land pattern 90-0187), measuring 1.6mm × 1.6mm with 0.65mm pitch. It is RoHS-compliant (+ suffix) and qualified for standard lead-free reflow soldering per JEDEC J-STD-020, with peak temperature rating of +260°C. The MAX6385XS26D3+T's thermal resistance (θJA = 322.6°C/W on multilayer board) supports reliable operation in compact, thermally dense layouts.

How does the reset timeout behavior differ between power-on and manual reset events for MAX6385XS26D3+T?

The MAX6385XS26D3+T provides a single 140ms minimum timeout period for both VCC-initiated and MR-initiated resets. Unlike the MAX6390, it does not implement separate timeout values for power-on versus manual reset. When VCC falls below 2.63V or MR is pulled low, the active-high RESET output remains asserted for ≥140ms after the condition clears. This uniform timing simplifies system timing analysis and ensures consistent boot behavior regardless of reset trigger source. The MAX6385XS26D3+T guarantees this specification across –40°C to +125°C.

Can MAX6385XS26D3+T monitor a second voltage rail, and if not, what alternatives in the same family support dual-rail supervision?

No, MAX6385XS26D3+T does not support auxiliary voltage monitoring. It supervises only the VCC rail. For dual-rail supervision, select MAX6387XS26D3+T, MAX6388XS26D3+T, or MAX6389XS26D3+T - these variants include a dedicated RESET IN pin that compares an external voltage against an internal 1.27V reference, enabling user-configurable secondary rail monitoring via resistor divider. All three share identical 2.63V VCC threshold and 140ms timeout with MAX6385XS26D3+T, ensuring drop-in compatibility where dual supervision is required.