Analog Devices Inc./Maxim Integrated MAX6385XS26D3+

Overview

MAX6385XS26D3+ from Maxim Integrated is a low-power, active-high push-pull microprocessor supervisory circuit with factory-set 2.63V reset threshold, 140ms minimum reset timeout, manual reset input (MR), and 4-pin SC70 package. It monitors VCC in battery-powered or low-voltage embedded systems and asserts RESET when supply drops below threshold, ensuring reliable µP initialization during brownout or power-up. Designed for portable instrumentation and industrial controllers requiring stable reset behavior down to VCC = 1V.

For engineers reviewing the MAX6385XS26D3+ datasheet, MAX6385XS26D3+ pinout, MAX6385XS26D3+ application, or MAX6385XS26D3+ equivalent, key selection considerations include its ±2.5% reset threshold accuracy over –40°C to +125°C, 3µA supply current at 1.8V, MR debounce capability, guaranteed valid output down to VCC = 1V, and compatibility with dual-supply monitoring architectures via external resistor dividers.

Technical Context

The MAX6385XS26D3+ implements a precision bandgap-based voltage comparator with internal 2.63V reference and a monolithic timer for fixed 140ms reset assertion after VCC recovery. Its active-high push-pull RESET output drives directly into µP reset inputs without external pull-up, and the debounced MR input includes a 63kΩ internal pullup to VCC.

This device operates across 1.0V–5.5V VCC range and guarantees correct logic state of RESET down to VCC = 1V. It features negative-going VCC transient immunity up to 35µs at 100mV overdrive and supports stable operation in noisy environments using optional 0.1µF MR-to-GND capacitor.

Key Specifications

Pinout & Package

MAX6385XS26D3+ uses a 4-pin SC70 package (X4-1 footprint, 1.0mm × 1.0mm × 0.55mm height) with exposed pad option not applicable. Pin 1 = VCC, Pin 2 = RESET, Pin 3 = MR, Pin 4 = GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326XR26D3+, MAX6385XS26D3+ adds MR functionality and push-pull drive, simplifying layout; versus TPS3123E18DBVR, it offers tighter timeout tolerance and integrated MR debounce, critical for field-serviceable designs.

Availability

MAX6385XS26D3+ is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, smart energy meters, and automotive body control units requiring stable component supply with guaranteed long-term availability.

Supply support for MAX6385XS26D3+ 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 industrial, automotive, communications, and computing markets.

The MAX6381–MAX6390 family delivers single/dual low-voltage supervisory circuits optimized for battery-powered and space-constrained embedded systems requiring ultra-low ICC, wide temperature operation, and robust reset timing control.

FAQ

What is the exact reset threshold voltage of MAX6385XS26D3+ and how tightly is it specified?

The MAX6385XS26D3+ has a factory-set reset threshold of 2.63V, with ±2.5% accuracy guaranteed over the full operating temperature range of –40°C to +125°C. This specification is confirmed in the Electrical Characteristics table under "VCC Reset Threshold" and applies directly to the MAX6385XS26D3+ variant. The threshold is trimmed during wafer sort and does not require external calibration.

Does MAX6385XS26D3+ support manual reset functionality, and how is it implemented?

Yes, MAX6385XS26D3+ includes a debounced manual reset input (MR) on Pin 3. Driving MR low for ≥1µs forces an immediate reset assertion, which remains active for the full 140ms timeout after MR returns high. An internal 63kΩ pullup resistor connects MR to VCC, so the pin may be left unconnected if unused - no external components are required for basic operation.

What package type and dimensions does MAX6385XS26D3+ use, and is it RoHS-compliant?

MAX6385XS26D3+ uses a 4-pin SC70 package (package code X4-1), measuring 1.0mm × 1.0mm × 0.55mm with standard lead-free finish. The "+" suffix in the part number explicitly denotes RoHS-compliant, lead-free construction per Maxim's ordering conventions and is verified in the Package Information section.

Can MAX6385XS26D3+ operate reliably during severe supply brownout conditions?

Yes, MAX6385XS26D3+ 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 even during deep brownout events common in automotive cranking or battery-depleted states - no external pulldown resistors are needed for active-high push-pull operation.

How does the reset timeout period of MAX6385XS26D3+ compare to other members of the MAX6381–MAX6390 family?

MAX6385XS26D3+ provides a fixed 140ms minimum reset timeout (suffix D3), matching the D3 option in the Reset Timeout Delay table. This is distinct from variants like MAX6385XS26D4 (1120ms) or MAX6385XS26D7 (1200ms). All timeouts are monotonic and guaranteed minimum values - actual duration may vary slightly with temperature but will never fall below the rated value.