Analog Devices Inc./Maxim Integrated MAX6389XS30D2+T

Overview

MAX6389XS30D2+T from Maxim Integrated is a low-power microprocessor supervisory circuit with open-drain active-low reset output, factory-set 3.00V ±2.5% reset threshold, and 20ms minimum reset timeout period. It monitors VCC from +1.8V to +5.0V while consuming only 3μA at +1.8V, and includes auxiliary RESET IN input for dual-voltage monitoring in battery-powered instrumentation.

For engineers reviewing the MAX6389XS30D2+T datasheet, MAX6389XS30D2+T pinout, MAX6389XS30D2+T application, or MAX6389XS30D2+T equivalent, key selection considerations include its 4-pin SC70 package, guaranteed reset validity down to VCC = 1V, ±2.5% threshold accuracy over –40°C to +125°C, and compatibility with resistor-divider–based secondary voltage monitoring via RESET IN.

Technical Context

The MAX6389XS30D2+T implements a precision bandgap-based reset comparator with 60ppm/°C tempco and internal +1.27V reference for the auxiliary RESET IN input. Its reset assertion logic responds to either VCC falling below 3.00V or RESET IN falling below 1.27V, with independent 4.5µs propagation delay from RESET IN to RESET output.

It features negative-going VCC transient immunity up to 150µs (at 100mV overdrive), guaranteed open-drain RESET output low voltage of 0.3V at 1.2mA sink current (VCC ≥ 2.5V), and 1.0µA leakage when not asserted - enabling reliable interface with 1.8V–5V logic systems without external level-shifting.

Key Specifications

Pinout & Package

MAX6389XS30D2+T is housed in a RoHS-compliant 4-pin SC70 package (outline 21-0098, land pattern 90-0187), with 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 MAX6389XS30D2+T, the D3 variant offers longer reset hold time for demanding boot sequences, while TLV809M30DBZR provides basic single-rail supervision at lower cost but omits the critical RESET IN feature required for dual-voltage systems.

Availability

MAX6389XS30D2+T is available at Aetrix Electronics and suitable for industrial sensor nodes, automotive body control modules, medical point-of-care devices, and portable test equipment requiring stable component supply with AEC-Q100–compatible sourcing.

Supply support for MAX6389XS30D2+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, mixed-signal, and power management ICs for demanding industrial, automotive, and computing applications.

The MAX6381–MAX6390 family delivers low-power, high-accuracy μP reset supervision with configurable thresholds, timeouts, and dual-voltage monitoring - targeting space- and power-constrained embedded systems requiring robust power-fail detection.

FAQ

What is the exact reset threshold voltage of MAX6389XS30D2+T and how stable is it over temperature?

The MAX6389XS30D2+T has a factory-set nominal reset threshold of 3.00V, with guaranteed tolerance of ±2.5% (±75mV) over the full operating temperature range of –40°C to +125°C. This stability is achieved through laser-trimmed bandgap references and low-tempco design, ensuring consistent brownout detection without external calibration. The MAX6389XS30D2+T maintains this accuracy across automotive and industrial thermal environments.

Does MAX6389XS30D2+T support monitoring of a second voltage rail, and how is it implemented?

Yes, MAX6389XS30D2+T includes a dedicated RESET IN input that compares an external voltage to an internal +1.27V reference. To monitor a second rail, connect a resistor divider between the target voltage and ground, with the midpoint fed to RESET IN. The MAX6389XS30D2+T asserts reset if either VCC falls below 3.00V or the divided voltage at RESET IN drops below 1.27V - enabling true dual-supply supervision in a single 4-pin device.

What is the function of the open-drain RESET output on MAX6389XS30D2+T, and what pullup voltage should be used?

The open-drain RESET output on MAX6389XS30D2+T requires an external pullup resistor to define the inactive (high) logic level. The pullup voltage may be set independently of VCC - e.g., 1.8V for interfacing with low-voltage I/O, 3.3V for standard logic, or 5V for legacy systems - providing voltage-level flexibility. The MAX6389XS30D2+T guarantees VOL ≤ 0.3V at 1.2mA sink current (VCC ≥ 2.5V), ensuring clean logic transitions across mixed-voltage designs.

Can MAX6389XS30D2+T operate reliably during brief power supply transients, and what is its immunity specification?

Yes, MAX6389XS30D2+T provides built-in immunity to negative-going VCC transients. According to its datasheet, it rejects glitches up to 150µs in duration when the overdrive (VTH – VCC) is 100mV - meaning it will not falsely assert reset during short dips that remain above the noise margin. This is validated by the "Maximum Transient Duration vs. Reset Comparator Overdrive" graph in the MAX6389XS30D2+T datasheet, making it suitable for electrically noisy automotive and industrial environments.

What package type and footprint does MAX6389XS30D2+T use, and are PCB layout guidelines available?

MAX6389XS30D2+T is supplied in a 4-pin SC70 package (outline number 21-0098, land pattern 90-0187), measuring 1.6mm × 1.6mm with 0.65mm pitch. Maxim provides verified land patterns and thermal guidelines - including θ_JA = 322.6°C/W on multilayer board - on their packaging portal. The MAX6389XS30D2+T requires no special layout beyond standard high-impedance analog routing for RESET IN and a solid ground connection to GND pin for accurate threshold sensing.