Analog Devices Inc./Maxim Integrated MAX6385XS46D4-T

Overview

MAX6385XS46D4-T from Maxim Integrated is a precision microprocessor supervisory circuit with active-high push-pull reset output, factory-set 4.63V reset threshold (±2.5% over -40°C to +125°C), 1120ms VCC reset timeout, and debounced manual reset input. It monitors single-supply rails in battery-powered controllers and embedded systems where reliable power-up sequencing and brownout protection are critical.

For engineers reviewing the MAX6385XS46D4-T datasheet, MAX6385XS46D4-T pinout, MAX6385XS46D4-T application, or MAX6385XS46D4-T equivalent, key selection factors include its guaranteed reset validity down to VCC = 1V, 3μA supply current at 1.8V, 4-pin SC70 package footprint, and compatibility with manual reset switch interfaces requiring no external debounce.

Technical Context

The MAX6385XS46D4-T implements a precision bandgap-based voltage comparator for VCC monitoring, paired with an internal monostable timer that enforces a minimum 1120ms reset assertion after VCC rises above 4.63V. Its MR input features a 63kΩ internal pullup resistor and guarantees reset assertion for ≥140ms after MR release.

This device operates across -40°C to +125°C with ±2.5% reset threshold accuracy and supports stable reset generation even during fast negative-going VCC transients-immune to glitches ≤35µs at 100mV overdrive-making it suitable for noisy industrial power environments.

Key Specifications

Pinout & Package

MAX6385XS46D4-T is housed in a RoHS-compliant 4-pin SC70 package (outline 21-0098, land pattern 90-0187), offering compact footprint (1.3mm × 1.1mm) and 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 MAX6385XS46D4-T, the D3 variant offers faster reset release for latency-sensitive systems, while MAX6326XR46D4-T removes MR functionality to reduce pin count and package size-both require careful evaluation of reset timing margins and system-level reset architecture.

Availability

MAX6385XS46D4-T is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body electronics, portable medical sensors, and battery-powered smart meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6385XS46D4-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 reliability, low power, and high integration.

The MAX6381–MAX6390 family delivers ultra-low-power, high-accuracy supervisory circuits optimized for microprocessor reset in space-constrained, thermally harsh, and battery-sensitive systems.

FAQ

What is the exact reset threshold voltage of MAX6385XS46D4-T and how stable is it over temperature?

The MAX6385XS46D4-T has a factory-set nominal reset threshold of 4.63V, with guaranteed accuracy of ±2.5% across the full operating temperature range of -40°C to +125°C. This stability is achieved through laser-trimmed bandgap references and process-compensated comparator design, ensuring predictable trip points in automotive and industrial environments where voltage rails may drift with temperature.

Does MAX6385XS46D4-T support manual reset functionality, and what are the electrical requirements for the MR pin?

Yes, MAX6385XS46D4-T includes a debounced manual reset (MR) input with a 63kΩ internal pullup resistor to VCC. To assert reset, MR must be driven below 0.3×VCC (for VTH < 4V) or below 0.8V (for VTH > 4V). The MR pin accepts TTL/CMOS logic levels and requires no external components-momentary switch-to-GND connection suffices. Minimum pulse width is 1µs, with 100ns glitch rejection.

What is the maximum supply voltage the MAX6385XS46D4-T can withstand, and what happens if VCC drops below 1.0V?

MAX6385XS46D4-T supports an absolute maximum VCC of +6.0V and operates down to 1.0V. Below 1.0V, the device ceases guaranteed operation-but crucially, the RESET output remains valid and correctly asserted or deasserted down to VCC = 1.0V. For applications requiring reset validity to 0V, external pulldown resistors are needed only for push-pull variants like MAX6385XS46D4-T.

How does the 1120ms reset timeout of MAX6385XS46D4-T compare to other members of the MAX6381–MAX6390 family?

The 1120ms timeout (denoted by suffix "D4") is one of seven standard delays available in the MAX6381–MAX6390 family. It is specifically selected for systems requiring extended initialization windows-such as those with slow-starting power supplies or complex bootloader sequences. Other options include 1ms (D1), 140ms (D3), and 1200ms (D7); MAX6385XS46D4-T does not support shorter or longer timeouts than its specified D4 configuration.

Is MAX6385XS46D4-T pin-compatible with legacy Maxim reset ICs such as MAX809 or MAX6326?

Yes, MAX6385XS46D4-T is pin-compatible with MAX809/MAX810/MAX803/MAX6326/MAX6327/MAX6328/MAX6346/MAX6347/MAX6348, and MAX6711/MAX6712/MAX6713 in the same 4-pin SC70 package. This allows drop-in replacement in existing designs-though designers must verify matching reset polarity (active-high), threshold (4.63V), and timeout (1120ms) to ensure functional equivalence.