Analog Devices Inc./Maxim Integrated MAX6385XS44D1-T

Overview

MAX6385XS44D1-T from Maxim Integrated is a low-power, active-high push-pull μP supervisory circuit designed to monitor +4.38V supply voltage and assert reset during power-up, brownout, or VCC drop below threshold. It features 140ms minimum reset timeout, manual reset input with internal pullup, guaranteed operation down to VCC = 1V, and consumes only 3μA at +1.8V. Used in portable battery-powered microcontroller systems requiring reliable power-on reset.

For engineers reviewing the MAX6385XS44D1-T datasheet, MAX6385XS44D1-T pinout, MAX6385XS44D1-T application, or MAX6385XS44D1-T equivalent, key selection criteria include factory-set 4.38V reset threshold accuracy (±2.5% over –40°C to +125°C), 140ms VCC reset timeout, active-high push-pull output logic, 4-pin SC70 package compatibility, and MR input debounce capability without external components.

Technical Context

The MAX6385XS44D1-T implements a precision bandgap-based voltage comparator monitoring VCC against a fixed +4.38V threshold, with ±2.5% tolerance across –40°C to +125°C. Its internal timer generates a guaranteed-minimum 140ms reset assertion after VCC rises above threshold.

It integrates a debounced manual reset input (MR) with 63kΩ internal pullup resistor, asserting reset on logic-low pulse ≥1μs width. Reset output remains active high for full timeout even if MR is released early, ensuring deterministic μP initialization in noisy embedded environments.

Key Specifications

Pinout & Package

MAX6385XS44D1-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 space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809SXR44D1-T, MAX6385XS44D1-T adds MR functionality in same footprint family while maintaining identical threshold and timing; versus TPS3808G14QDBVRQ1, it avoids external components and simplifies interface but lacks AEC-Q100 certification out-of-box.

Availability

MAX6385XS44D1-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 production continuity.

Supply support for MAX6385XS44D1-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 connectivity applications in industrial, automotive, and consumer markets.

The MAX6381–MAX6390 family delivers ultra-low-power, factory-trimmed supervisory circuits targeting battery-operated and thermally demanding embedded systems where reliability and minimal footprint are critical.

FAQ

What is the exact reset threshold voltage of the MAX6385XS44D1-T?

The MAX6385XS44D1-T has a factory-set nominal reset threshold of +4.38V, with guaranteed tolerance of ±2.5% over the full operating temperature range of –40°C to +125°C. This value is confirmed in the Reset Thresholds table of the datasheet (suffix "44" corresponds to 4.27V min / 4.38V nom / 4.48V max). The MAX6385XS44D1-T uses this precise threshold to monitor 4.5V rails in portable and industrial applications.

Does the MAX6385XS44D1-T support manual reset functionality?

Yes, the MAX6385XS44D1-T includes a dedicated active-low manual reset input (MR) with an internal 63kΩ pullup resistor to VCC. Driving MR low for ≥1μs forces reset assertion, which remains active for the full 140ms timeout period after MR is released. This feature is explicitly documented in the Pin Description and Features sections, and distinguishes MAX6385XS44D1-T from non-MR variants like MAX6381/MAX6382.

What package type and pin count does the MAX6385XS44D1-T use?

The MAX6385XS44D1-T is packaged in a 4-pin SC70 (SOT-323) outline, with pin 1 = VCC, pin 2 = RESET, pin 3 = GND, and pin 4 = MR. This is confirmed in the Ordering Information table (MAX6385XS_ _D_+T) and Pin Configurations diagram (page 9, SC70 top view showing 4 pins labeled VCC–RESET–GND–MR). The package code is X4+1, outline number 21-0098.

Is the MAX6385XS44D1-T compatible with microcontrollers requiring active-high reset signals?

Yes, the MAX6385XS44D1-T provides an active-high push-pull reset output, meaning RESET goes high during reset assertion and returns low when deasserted. This matches the active-high reset input requirements of many modern MCUs (e.g., STM32L4, NXP Kinetis). The datasheet explicitly states "MAX6382/MAX6385/MAX6388 have a push-pull active-high reset output", confirming direct compatibility without level-shifting.

What is the minimum supply voltage at which the MAX6385XS44D1-T guarantees correct reset output state?

The MAX6385XS44D1-T guarantees valid reset output logic state down to VCC = +1.0V, as specified in the Absolute Maximum Ratings and Electrical Characteristics tables. This ensures deterministic reset behavior during deep brownout conditions - for example, when a lithium coin cell discharges below 2.0V. The reset output remains functional and correctly asserted/deasserted even at this low voltage, a key reliability feature confirmed across –40°C to +125°C.