Analog Devices Inc./Maxim Integrated MAX6387LT46D4+T

Overview

MAX6387LT46D4+T from Maxim Integrated is a dual-voltage microprocessor supervisory circuit with active-low push-pull reset output, factory-set 4.63V VCC reset threshold (±2.5% over –40°C to +125°C), 1120ms minimum VCC reset timeout, and auxiliary RESET IN input for monitoring a second voltage source. It consumes only 3μA at +1.8V and operates down to VCC = 1.0V, used in dual-rail power systems requiring reliable brownout detection and system-level reset coordination.

For engineers reviewing the MAX6387LT46D4+T datasheet, MAX6387LT46D4+T pinout, MAX6387LT46D4+T application, or MAX6387LT46D4+T equivalent, key selection considerations include its dual-monitoring capability (VCC + RESET IN), guaranteed reset validity at low supply voltages, ±2.5% threshold accuracy across automotive temperature range, and compatibility with 4-pin SC70 or 6-pin μDFN layouts.

Technical Context

The MAX6387LT46D4+T integrates two independent reset comparators: one monitors VCC against a fixed 4.63V threshold, while the second compares an external voltage applied to RESET IN against an internal 1.27V reference. Reset asserts when either monitored voltage falls below its respective threshold, and remains asserted for 1120ms after recovery.

It features a push-pull active-low RESET output capable of sinking 3.2mA at VCC ≥ 4.5V (VOL ≤ 0.4V), with guaranteed logic-state validity down to VCC = 1.0V. The device uses BiCMOS process technology and supports operation from –40°C to +125°C with AEC-Q100 qualification available in /V variants.

Key Specifications

Pinout & Package

MAX6387LT46D4+T is available in 4-pin SC70 (package code X4+1) and 6-pin μDFN (package code L611+1). The 4-pin SC70 variant is used in space-constrained designs where RESET IN functionality is retained without manual reset.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6387XS46D4+T, the MAX6387LT46D4+T offers higher thermal dissipation margin (167.7mW vs. 245mW) in μDFN, while TLV809E46DBZR trades dual monitoring and longer timeout for lower power and smaller size - making it unsuitable for applications requiring coordinated dual-rail reset assertion.

Availability

MAX6387LT46D4+T is available at Aetrix Electronics and suitable for industrial PLC power monitoring, automotive body control modules, medical infusion pump controllers, and smart energy meter designs requiring stable component supply with long-term lifecycle support.

Supply support for MAX6387LT46D4+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 emphasis on low-power, high-reliability solutions.

The MAX6381–MAX6390 family delivers single/dual low-voltage microprocessor supervisory circuits optimized for brownout protection, reset coordination, and dual-rail power integrity in harsh-environment systems.

FAQ

What is the exact reset threshold voltage of MAX6387LT46D4+T and how stable is it over temperature?

The MAX6387LT46D4+T has a factory-set nominal VCC reset threshold of 4.63V, 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 internal references and BiCMOS process design, ensuring consistent brownout detection without external calibration. The MAX6387LT46D4+T maintains this specification across all production units without binning or post-assembly adjustment.

Does MAX6387LT46D4+T support monitoring of a second voltage, and how is it implemented?

Yes, MAX6387LT46D4+T includes a dedicated RESET IN input that compares an external voltage to an internal 1.27V reference. To monitor a second rail (e.g., 3.3V or 2.5V), connect a resistor divider between that rail and GND, with the midpoint fed to RESET IN. The threshold is set using R1 = R2 × ((V_INTH/1.27V) – 1), where V_INTH is the desired trip point. The MAX6387LT46D4+T asserts reset if either VCC drops below 4.63V or the divided voltage at RESET IN falls below 1.27V.

What is the reset timeout duration for MAX6387LT46D4+T and is it adjustable?

The MAX6387LT46D4+T provides a fixed minimum VCC reset timeout of 1120ms, as indicated by the "D4" suffix in the part number. This value is factory-programmed and not user-adjustable. The timeout begins when VCC rises above 4.63V and ends 1120ms later, ensuring sufficient hold time for microprocessor initialization, memory clearing, and peripheral stabilization before release. No external components or configuration pins modify this interval.

Can MAX6387LT46D4+T operate reliably at very low supply voltages?

Yes, MAX6387LT46D4+T guarantees correct RESET output logic state down to VCC = 1.0V, enabling robust operation during deep brownout conditions. Its internal circuitry remains functional and the push-pull output maintains valid low/high states even as supply collapses - unlike open-drain alternatives that require external pullups and may float unpredictably. This behavior is verified across –40°C to +125°C and is critical for fail-safe shutdown sequencing in MAX6387LT46D4+T-based systems.

What package options are available for MAX6387LT46D4+T and what are their key mechanical differences?

MAX6387LT46D4+T is offered in two RoHS-compliant packages: 6-pin μDFN (outline 21-0147, land pattern 90-0080) and 4-pin SC70 (outline 21-0098, land pattern 90-0187). The μDFN measures 2mm × 2mm × 0.55mm with exposed pad for thermal enhancement (θ_JA = 477°C/W), while the SC70 is 1.3mm × 1.6mm × 0.9mm (θ_JA = 322.6°C/W). Both use lead-free terminations and support reflow soldering at +260°C.