Analog Devices Inc./Maxim Integrated MAX6385XS33D5-T

Overview

MAX6385XS33D5-T from Maxim Integrated is a push-pull active-high microprocessor supervisory circuit with factory-set 3.3V reset threshold, 280ms minimum VCC reset timeout, and manual reset input. It monitors +1.8V to +5.0V supply rails, consumes only 3μA at +1.8V, guarantees valid reset output down to VCC = 1V, and operates across –40°C to +125°C for use in battery-powered industrial controllers.

For engineers reviewing the MAX6385XS33D5-T datasheet, MAX6385XS33D5-T pinout, MAX6385XS33D5-T application, or MAX6385XS33D5-T equivalent, key selection criteria include its 3.3V ±2.5% threshold accuracy over temperature, 280ms reset timeout, 4-pin SC70 package, active-high push-pull output, and integrated MR pullup resistor - all critical for reliable power-on reset in space-constrained embedded systems.

Technical Context

The MAX6385XS33D5-T implements a precision voltage comparator with internal 3.3V reference and a monostable timer that asserts RESET high when VCC falls below 3.3V (±2.5% over –40°C to +125°C) and holds it for ≥280ms after VCC recovers. Its MR input features a 63kΩ internal pullup and accepts TTL/CMOS logic levels.

This device belongs to the MAX6384–MAX6390 family of low-power supervisors, distinguished by active-high push-pull output and debounced manual reset capability. Unlike open-drain variants, it drives RESET high without external components and maintains output validity down to VCC = 1V - enabling robust reset signaling during brownout recovery.

Key Specifications

Pinout & Package

MAX6385XS33D5-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 with gull-wing leads. Thermal resistance θ_JA = 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 MAX6385XS33D3-T, the MAX6385XS33D5-T provides double the reset timeout for systems needing extended initialization windows; versus TPS3123E18DBVR, it integrates MR functionality and uses a smaller SC70 footprint but trades off absolute threshold tolerance for broader temperature stability.

Availability

MAX6385XS33D5-T is available at Aetrix Electronics and suitable for industrial PLC controllers, battery-powered sensor nodes, automotive body control modules, medical handheld diagnostic devices, and portable instrumentation requiring stable component supply and long-term lifecycle support.

Supply support for MAX6385XS33D5-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 industrial, automotive, and computing applications, with expertise in low-power supervision and power management.

The MAX6381–MAX6390 product line delivers single/dual-voltage microprocessor reset circuits optimized for ultra-low quiescent current, wide temperature operation, and compact packaging in SC70 and μDFN formats.

FAQ

What is the exact reset threshold voltage of MAX6385XS33D5-T and how does it vary with temperature?

The MAX6385XS33D5-T has a factory-set nominal reset threshold of 3.3V, with ±2.5% accuracy guaranteed over the full –40°C to +125°C operating range. At +25°C, the threshold is specified as 3.3V ±1.5%. This tight tolerance ensures reliable detection of 3.3V supply faults without false triggering during thermal cycling in industrial or automotive environments. The MAX6385XS33D5-T uses laser-trimmed on-chip resistors to achieve this stability.

Does MAX6385XS33D5-T support manual reset, and what is the internal pullup value on the MR pin?

Yes, MAX6385XS33D5-T includes a debounced manual reset input (MR) pin 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 required. The MR pin accepts TTL/CMOS logic levels and remains functional down to VCC = 1V. The MAX6385XS33D5-T datasheet confirms the pullup value is 32kΩ to 100kΩ (typical 63kΩ) across temperature.

What is the minimum VCC voltage at which MAX6385XS33D5-T guarantees correct RESET output logic state?

The MAX6385XS33D5-T guarantees valid RESET output logic state down to VCC = 1.0V. Below this voltage, the internal circuitry may not maintain defined output behavior. This specification ensures deterministic reset signaling during slow power-down events - critical for preventing spurious microprocessor execution in battery-backed or energy-harvesting systems. The MAX6385XS33D5-T achieves this via proprietary low-voltage comparator design.

What package type and dimensions does MAX6385XS33D5-T use, and is it RoHS-compliant?

MAX6385XS33D5-T uses a 4-pin SC70 package (outline number 21-0098, land pattern 90-0187), measuring 2.0mm × 2.1mm × 0.95mm with gull-wing leads. It is RoHS-compliant and lead-free, indicated by the "+" suffix in the ordering code. The package supports reflow soldering per JEDEC J-STD-020 (peak 260°C) and has thermal resistance θ_JA = 322.6°C/W on a multilayer PCB. This compact footprint makes the MAX6385XS33D5-T ideal for space-constrained portable electronics.

How does the reset timeout period of MAX6385XS33D5-T compare to other members of the MAX6384–MAX6390 family?

The MAX6385XS33D5-T has a 280ms minimum VCC reset timeout, corresponding to the "D5" suffix in its part number. This places it between the 140ms (D3) and 560ms (D6) variants. All timeouts are monotonic and guaranteed minimum values - actual durations may be longer due to process variation. The MAX6385XS33D5-T shares identical timeout architecture with MAX6384/MAX6386 but differs from MAX6390, which offers separate VCC (1120ms/1200ms) and MR (140ms/150ms) timeout periods.