Analog Devices Inc./Maxim Integrated MAX6385XS31D1+

Overview

MAX6385XS31D1+ from Maxim Integrated is a precision active-high push-pull μP supervisory circuit designed for reliable power-on reset and brownout detection in low-voltage embedded systems. It features a factory-set 3.08V reset threshold (±2.5% over -40°C to +125°C), 140ms minimum VCC reset timeout, 3μA supply current at 1.8V, and operates down to VCC = 1.0V. It is used in portable battery-powered equipment requiring deterministic reset assertion during voltage sag.

For engineers reviewing the MAX6385XS31D1+ datasheet, MAX6385XS31D1+ pinout, MAX6385XS31D1+ application, or MAX6385XS31D1+ equivalent, key selection criteria include its 4-pin SC70 package, manual reset input with internal 63kΩ pullup, guaranteed valid reset output down to 1V, and compatibility with dual-rail voltage monitoring architectures.

Technical Context

The MAX6385XS31D1+ integrates a precision bandgap-based voltage comparator with hysteresis and an internal monostable timer. Its reset logic asserts high when VCC falls below 3.08V or when the MR pin is pulled low, holding the active-high RESET output for ≥140ms after recovery. The device guarantees correct output state down to VCC = 1.0V, enabling robust operation during deep brownout conditions.

It includes a debounced manual reset input (MR) with 1µs minimum pulse width support and 100ns glitch rejection. The internal 63kΩ pullup resistor allows direct connection of a momentary switch to GND without external components. Unlike variants with RESET IN, this part lacks auxiliary voltage monitoring capability.

Key Specifications

Pinout & Package

MAX6385XS31D1+ is housed in a RoHS-compliant 4-pin SC70 package (outline 21-0098, land pattern 90-0187), measuring 2.0mm × 2.1mm × 0.95mm. This ultra-compact footprint supports high-density portable designs while maintaining thermal resistance θJA = 322.6°C/W on multilayer boards.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6385XS31D1+, the μDFN variant offers better thermal performance at the expense of board area, while the MAX809TRD1+T sacrifices manual reset flexibility for minimal footprint - making MAX6385XS31D1+ optimal for space-constrained, user-serviceable portable electronics.

Availability

MAX6385XS31D1+ is available at Aetrix Electronics and suitable for portable medical sensors, battery-powered telematics units, industrial handheld scanners, and smart home edge controllers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6385XS31D1+ 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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and communications markets.

The MAX6381–MAX6390 family delivers ultra-low-power, precision reset supervision for battery-critical and thermally demanding embedded systems - engineered specifically for reliable operation in portable, automotive, and industrial control applications.

FAQ

What is the exact reset threshold voltage of MAX6385XS31D1+ and how stable is it over temperature?

The MAX6385XS31D1+ has a factory-set nominal reset threshold of 3.08V, 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 bandgap references and matched transistor pairs in the BiCMOS process, ensuring consistent trip points across automotive and industrial environments without external calibration.

Does MAX6385XS31D1+ support manual reset, and what are the interface requirements?

Yes, MAX6385XS31D1+ includes a dedicated MR (manual reset) input with an internal 63kΩ pullup resistor to VCC. To assert reset, drive MR low with a momentary switch to GND or compatible logic signal. The device accepts TTL/CMOS levels and rejects glitches <100ns. No external components are required unless additional noise immunity is needed - then a 0.1µF capacitor from MR to GND is recommended.

Can MAX6385XS31D1+ operate reliably when VCC drops below 1.8V?

Yes, MAX6385XS31D1+ guarantees correct reset output behavior down to VCC = 1.0V. Its internal comparator and timer remain functional at this level, ensuring the active-high RESET signal stays asserted until VCC recovers above 3.08V and the 140ms timeout expires. This capability is critical for brownout recovery in systems powered by depleting batteries or unstable energy harvesters.

What package type and dimensions does MAX6385XS31D1+ use, and is it RoHS-compliant?

MAX6385XS31D1+ uses a lead(Pb)-free, RoHS-compliant 4-pin SC70 package (outline 21-0098) measuring 2.0mm × 2.1mm × 0.95mm. The "+" suffix in the part number explicitly denotes RoHS compliance. Its compact size supports high-density layouts in wearables and handheld devices, while the thermal resistance θJA = 322.6°C/W is characterized per JEDEC JESD51-7 on multilayer boards.

How does the reset timeout period of MAX6385XS31D1+ compare to other members of the MAX6381–MAX6390 family?

MAX6385XS31D1+ provides a 140ms minimum reset timeout (D3 suffix), matching the timing of MAX6381–MAX6389 variants with the same D3 designation. This differs from MAX6390 (which offers 140ms/150ms manual reset timeout paired with 1120ms/1200ms VCC timeout) and shorter-duration versions like D1 (1ms) or longer ones like D7 (1200ms). The D3 value balances MCU initialization needs against system responsiveness.