Analog Devices Inc./Maxim Integrated MAX6385XS31D2-T

Overview

MAX6385XS31D2-T from Maxim Integrated is a push-pull active-high microprocessor supervisory circuit with factory-set 3.08V reset threshold, 20ms minimum reset timeout, and manual reset input (MR). It monitors VCC from +1.8V to +5.0V, consumes only 3μA at +1.8V, and guarantees valid reset output down to VCC = 1V. It is used in battery-powered controllers and portable instrumentation requiring precise brownout detection and reliable power-on reset.

For engineers reviewing the MAX6385XS31D2-T datasheet, MAX6385XS31D2-T pinout, MAX6385XS31D2-T application, or MAX6385XS31D2-T equivalent, key selection criteria include its 3.08V ±2.5% threshold accuracy over –40°C to +125°C, 20ms reset timeout, MR debounce capability, SC70-4 package footprint, and compatibility with dual-voltage systems requiring auxiliary monitoring support.

Technical Context

The MAX6385XS31D2-T implements a precision bandgap-based voltage comparator with ±2.5% threshold accuracy across temperature, paired with a monolithic timer for deterministic 20ms reset assertion after VCC recovery. Its internal 63kΩ MR pullup enables direct connection of a momentary switch to GND without external components.

It features active-high push-pull RESET output capable of sourcing 500µA at VCC ≥ 2.5V while maintaining VOH ≥ 0.8×VCC, and guarantees correct logic state down to VCC = 1V - critical for low-voltage microcontroller startup sequencing in energy-constrained designs.

Key Specifications

Pinout & Package

MAX6385XS31D2-T is housed in a RoHS-compliant 4-pin SC70 package (outline 21-0098), measuring 2.0mm × 2.1mm × 0.95mm, with 0.65mm lead pitch and thermal resistance θJA = 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 MAX809TRD2-T and TPS3808G30DBVR, the MAX6385XS31D2-T uniquely combines 20ms timeout, integrated MR pullup, SC70-4 compactness, and guaranteed 3.08V accuracy - making it optimal for space-constrained, manually serviceable embedded systems requiring precise reset timing.

Availability

MAX6385XS31D2-T is available at Aetrix Electronics and suitable for portable instrumentation, industrial controllers, battery-powered wireless sensors, and dual-voltage embedded systems requiring stable component supply and automotive-grade temperature performance.

Supply support for MAX6385XS31D2-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, mixed-signal, and power management ICs for demanding industrial, automotive, and computing applications.

The MAX6381–MAX6390 family delivers low-power, factory-trimmed μP supervisory circuits optimized for reliable reset generation in space- and power-constrained systems with wide input voltage and temperature requirements.

FAQ

What is the exact reset threshold voltage of the MAX6385XS31D2-T and how stable is it over temperature?

The MAX6385XS31D2-T has a factory-set reset threshold of 3.08V, specified with ±2.5% tolerance over the full –40°C to +125°C operating range. This stability is achieved through laser-trimmed bandgap references and matched comparator design, ensuring consistent brownout detection without external calibration. The MAX6385XS31D2-T maintains this accuracy across all conditions where VCC remains within 1.0V to 5.5V.

Does the MAX6385XS31D2-T require an external pullup resistor on the MR pin?

No, the MAX6385XS31D2-T includes an internal 63kΩ pullup resistor on the MR pin, allowing direct connection of a momentary switch to GND without additional components. This feature simplifies PCB layout and reduces BOM count. The MAX6385XS31D2-T's MR input accepts TTL/CMOS logic levels and supports noise immunity via optional 0.1μF capacitor to GND in electrically noisy environments.

What is the function and electrical behavior of the RESET output on the MAX6385XS31D2-T?

The RESET output of the MAX6385XS31D2-T is an active-high push-pull driver that transitions high when VCC falls below 3.08V or MR is asserted, and remains high for a guaranteed minimum 20ms after VCC recovers or MR is released. It sources ≥500µA at VCC ≥ 2.5V with VOH ≥ 0.8×VCC, and operates correctly down to VCC = 1V - ensuring robust reset signaling even during severe brownout conditions. The MAX6385XS31D2-T does not require external pullup or pulldown resistors on this pin.

Can the MAX6385XS31D2-T be used in automotive applications, and what qualification does it hold?

The MAX6385XS31D2-T is offered in a /V automotive-qualified variant (e.g., MAX6385XS31D2/V+T), which meets AEC-Q100 Grade 2 requirements (–40°C to +105°C ambient) and is manufactured in an automotive-grade flow. While the standard MAX6385XS31D2-T is rated for –40°C to +125°C junction temperature, its design and test coverage align with automotive reliability standards. Always specify the /V suffix for production automotive use, as the MAX6385XS31D2-T base part lacks formal AEC-Q100 certification documentation.

How does the MAX6385XS31D2-T handle negative-going VCC transients, and what protection measures are recommended?

The MAX6385XS31D2-T provides inherent immunity to short-duration negative-going VCC transients (glitches) due to internal comparator overdrive filtering. Its typical maximum transient duration without false reset is 350µs for a 100mV overdrive (VTH – VCC), decreasing as overdrive increases. To enhance immunity, place a 0.1μF ceramic capacitor as close as possible to the VCC pin. This decoupling significantly improves noise rejection in motor-drive or switching-power-supply environments where the MAX6385XS31D2-T is deployed.