Analog Devices Inc./Maxim Integrated MAX6389XS30D2+

Overview

MAX6389XS30D2+ from Maxim Integrated is a low-power microprocessor supervisory circuit with open-drain active-low reset output, factory-set 3.00V reset threshold (±2.5% over -40°C to +125°C), and 20ms minimum reset timeout. It monitors VCC from +1.8V to +5.0V while consuming only 3μA at +1.8V, and features an auxiliary RESET IN input for dual-voltage monitoring in embedded power management systems.

For engineers reviewing the MAX6389XS30D2+ datasheet, MAX6389XS30D2+ pinout, MAX6389XS30D2+ application, or MAX6389XS30D2+ equivalent, key selection criteria include its 4-pin SC70 package, guaranteed reset validity down to VCC = 1V, ±2.5% threshold accuracy over temperature, and compatibility with dual-rail systems requiring independent core/I/O voltage supervision.

Technical Context

The MAX6389XS30D2+ implements a precision bandgap-based reset comparator with internal +1.27V reference for the RESET IN input, enabling user-adjustable secondary voltage monitoring via external resistor divider. Its open-drain RESET output requires an external pullup and guarantees correct logic state down to VCC = 1V.

It features negative-going VCC transient immunity up to 35µs at 100mV overdrive, supports manual reset assertion via MR input (internal 63kΩ pullup), and delivers stable reset timing across -40°C to +125°C with <60ppm/°C reset threshold tempco.

Key Specifications

Pinout & Package

MAX6389XS30D2+ is housed in a RoHS-compliant 4-pin SC70 package (package code X4+1), footprint-optimized for space-constrained PCB layouts. Pin 1 = VCC, Pin 2 = RESET (open-drain active-low), Pin 3 = GND, Pin 4 = RESET IN.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6389XS30D2+, MAX6389XS30D3+ extends reset hold time for complex boot sequences, while TLV809K30DBZR trades dual-monitoring capability for lower cost and simpler integration in single-rail systems - neither offers pin-compatible replacement due to differing pin count and functionality.

Availability

MAX6389XS30D2+ is available at Aetrix Electronics and suitable for industrial PLC power monitoring, automotive body control modules, medical portable diagnostic devices, and smart energy meters requiring stable component supply with AEC-Q100-aligned reliability.

Supply support for MAX6389XS30D2+ 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 power efficiency and reliability.

The MAX6381–MAX6390 family delivers low-power, temperature-stable microprocessor supervision with configurable thresholds and dual-rail monitoring - engineered specifically for mission-critical embedded systems needing deterministic reset behavior under voltage stress.

FAQ

What is the exact reset threshold voltage of MAX6389XS30D2+ and how does it vary with temperature?

The MAX6389XS30D2+ has a factory-set nominal reset threshold of 3.00V, with a minimum of 2.93V and maximum of 3.08V at +25°C. Over the full operating temperature range of -40°C to +125°C, the threshold maintains ±2.5% accuracy (i.e., 2.925V to 3.075V at worst-case extremes), supported by a 60ppm/°C tempco for predictable drift behavior in thermal cycling environments.

Does MAX6389XS30D2+ support monitoring of two independent voltage rails?

Yes, MAX6389XS30D2+ supports dual-rail monitoring: its primary VCC pin monitors the main supply (e.g., 3.3V or 5V), while the dedicated RESET IN pin connects to an external resistor divider to set a custom threshold for a second rail (e.g., 1.8V core or 2.5V analog). Reset asserts if either voltage falls below its respective threshold, making MAX6389XS30D2+ ideal for SoC or multi-domain power systems.

What is the function of the RESET IN pin on MAX6389XS30D2+ and how is it configured?

The RESET IN pin on MAX6389XS30D2+ is a high-impedance input to an internal +1.27V comparator. To monitor a secondary voltage, connect it to the center node of a resistor divider between the target rail and ground. The threshold is calculated as V_TH = 1.27V × (R1/R2 + 1), where R2 is selected first and R1 derived accordingly. MAX6389XS30D2+ asserts reset if the voltage at RESET IN drops below 1.27V, enabling precise, user-defined supervision of auxiliary supplies.

What package type and pin count does MAX6389XS30D2+ use, and is it RoHS-compliant?

MAX6389XS30D2+ uses a 4-pin SC70 package (land pattern 90-0187, package code X4+1), measuring 2.0mm × 2.1mm with 0.65mm pitch. The "+" suffix confirms lead(Pb)-free and RoHS-compliant construction. This compact footprint supports high-density PCB layouts in space-constrained applications such as portable medical devices and automotive ECUs.

How does the open-drain RESET output of MAX6389XS30D2+ differ from push-pull alternatives?

The open-drain RESET output of MAX6389XS30D2+ requires an external pullup resistor to define the high-state voltage, enabling wired-OR connection with other reset sources (e.g., watchdog timers or manual reset buttons) on a shared reset bus. Unlike push-pull outputs, it cannot actively drive high, eliminating contention risk and allowing flexible voltage translation - essential for mixed-voltage systems where reset logic levels must interface with diverse IC families.