Analog Devices Inc./Maxim Integrated MAX6385XS29D3+T

Overview

MAX6385XS29D3+T from Maxim Integrated is a low-power, active-high push-pull μP supervisory circuit with factory-set 2.93V reset threshold, 140ms minimum VCC reset timeout, and manual reset input (MR). It monitors +1.8V to +5.0V supply rails in space-constrained embedded systems and guarantees valid reset output down to VCC = 1V. Designed for battery-powered controllers and critical microprocessor power sequencing.

For engineers reviewing the MAX6385XS29D3+T datasheet, MAX6385XS29D3+T pinout, MAX6385XS29D3+T application, or MAX6385XS29D3+T equivalent, key selection criteria include its 2.93V ±2.5% threshold accuracy over –40°C to +125°C, 3μA supply current at 1.8V, MR debounce capability, and 4-pin SC70 package compatibility with legacy MAX809/MAX810 designs.

Technical Context

The MAX6385XS29D3+T implements a precision bandgap-based voltage comparator with ±2.5% threshold accuracy across temperature, paired with a monolithic RC timer for deterministic 140ms reset assertion after VCC recovery. Its internal 63kΩ MR pullup resistor enables direct connection of a momentary switch to GND without external components.

This device belongs to the MAX6384–MAX6390 family with active-high push-pull RESET output and debounced MR input. Unlike open-drain variants, it drives high during reset assertion and requires no external pullup; unlike dual-monitor parts, it lacks RESET IN functionality and monitors only VCC.

Key Specifications

Pinout & Package

MAX6385XS29D3+T is housed in a RoHS-compliant 4-pin SC70 package (outline 21-0098, land pattern 90-0187), measuring 1.3mm × 1.6mm × 0.95mm, optimized for high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6385XS29D3+T, MAX6326XR29D3+T saves board space by omitting MR but forces redesign of reset logic polarity, while TPS3123E18DBVR reduces supply current by 60% yet removes field-serviceability via manual reset - making MAX6385XS29D3+T optimal for balanced performance, serviceability, and footprint in industrial edge nodes.

Availability

MAX6385XS29D3+T is available at Aetrix Electronics and suitable for industrial PLC controllers, battery-powered data loggers, automotive body control modules, and portable medical diagnostics requiring stable component supply and long-term lifecycle support.

Supply support for MAX6385XS29D3+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 demanding industrial, automotive, and computing applications, with emphasis on low-power, high-reliability solutions.

The MAX6381–MAX6390 family delivers single/dual-supply μP reset supervision with sub-μA quiescent current and AEC-Q100 qualification, targeting space- and power-constrained embedded systems needing guaranteed power-on reset behavior.

FAQ

What is the exact reset threshold voltage of MAX6385XS29D3+T and how tightly is it specified?

The MAX6385XS29D3+T has a nominal reset threshold of 2.93V, with guaranteed tolerance of ±2.5% over the full operating temperature range of –40°C to +125°C. This specification is validated per the Electrical Characteristics table in the official datasheet, where VTH min = 2.85V and VTH max = 3.00V at TA = –40°C to +125°C. The threshold is factory-trimmed using laser or fuse techniques and does not require external calibration.

Does MAX6385XS29D3+T support manual reset, and what is the internal pullup value?

Yes, MAX6385XS29D3+T features a debounced active-low manual reset input (MR) with an internal 63kΩ pullup resistor to VCC. This allows direct connection of a normally open momentary switch between MR and GND - no external components are needed. The MR input accepts TTL/CMOS logic levels and remains functional down to VCC = 1.0V, as confirmed in the Electrical Characteristics table under "MR Internal Pullup Resistance".

What package type and dimensions does MAX6385XS29D3+T use, and is it RoHS-compliant?

MAX6385XS29D3+T is supplied in a lead(Pb)-free, RoHS-compliant 4-pin SC70 package (outline number 21-0098, land pattern 90-0187), measuring 1.3mm × 1.6mm × 0.95mm. The "+T" suffix explicitly denotes tape-and-reel packaging with RoHS compliance, and thermal resistance values (θJA = 322.6°C/W) are published for multilayer board mounting per JEDEC JESD51-7.

Can MAX6385XS29D3+T operate reliably at VCC = 1.0V, and what is its behavior below that?

Yes, MAX6385XS29D3+T guarantees correct RESET output logic state for VCC ≥ 1.0V - meaning it will assert active-high RESET properly during brownout and deassert cleanly upon recovery, even at 1.0V. Below 1.0V, operation is not specified; the device enters undervoltage lockout and RESET behavior becomes undefined. This 1.0V lower limit is explicitly stated in the Absolute Maximum Ratings and Electrical Characteristics tables.

How does the 140ms reset timeout of MAX6385XS29D3+T compare to other timing options in the MAX6384–MAX6390 family?

The "D3" suffix in MAX6385XS29D3+T specifies a minimum reset timeout of 140ms, one of seven standard delays (1ms, 20ms, 140ms, 280ms, 560ms, 1120ms, 1200ms). This value is selected for mid-range microcontrollers requiring sufficient initialization time without excessive boot delay. It matches the D3 option in MAX6384/MAX6386 variants and differs from MAX6390's split timing (e.g., 1120ms VCC + 140ms MR), confirming identical timeout architecture within the MAX6384–MAX6386 subgroup.