Analog Devices Inc./Maxim Integrated MAX6423US22+T

Overview

MAX6423US22+T from Analog Devices is a low-power microprocessor supervisor IC with open-drain active-low reset output, 2.188V ±2.5% factory-trimmed reset threshold, capacitor-adjustable reset timeout (275µs to 5.75ms), and guaranteed operation down to VCC = 1V. It monitors supply voltage in portable and battery-powered systems to prevent erroneous µP startup during brownout.

For engineers reviewing the MAX6423US22+T datasheet, MAX6423US22+T pinout, MAX6423US22+T application, or MAX6423US22+T equivalent, key selection factors include its SC70-4 package, 1.6µA typical quiescent current, open-drain logic compatibility with multiple supply rails, immunity to short VCC transients, and reset timeout programmability via external capacitor.

Technical Context

The MAX6423US22+T implements a precision voltage detector using laser-trimmed resistors to set its 2.188V reset threshold with ±2.5% accuracy over –40°C to +125°C. Its internal 240nA ramp current charges an external SRT capacitor to generate a reset timeout period governed by tRP = 2.73×10⁶ × CSRT + 275µs.

It features an open-drain RESET output requiring an external pullup resistor (10kΩ–100kΩ), supports logic-level interfacing up to 5.5V, and maintains valid reset assertion down to VCC = 1V. The SRT pin is sensitive to board leakage and stray capacitance, demanding careful PCB layout for timing accuracy.

Key Specifications

Pinout & Package

MAX6423US22+T is housed in a 4-pin SC70 package (package code X4+1, outline 21-0098), measuring 2.0mm × 2.1mm × 0.95mm, with gull-wing leads and RoHS-compliant lead-free finish ("+T" suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6423US22+T, the MAX6423US22D+T offers identical supervision performance in a mechanically distinct package, while the NCP302LS22T1G trades timeout programmability and open-drain versatility for lower cost and simpler implementation in non-critical systems.

Availability

MAX6423US22+T is available at Aetrix Electronics and suitable for portable medical sensors, battery-powered industrial controllers, and automotive body control modules requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for MAX6423US22+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

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets since 1965.

The MAX6421–MAX6426 family was designed specifically for ultra-low-power, precision voltage monitoring in space-constrained portable and battery-operated systems where reset accuracy, timing flexibility, and supply robustness are critical.

FAQ

What is the exact reset threshold voltage of MAX6423US22+T?

The MAX6423US22+T has a factory-laser-trimmed nominal reset threshold of 2.188V, with ±2.5% accuracy over the full operating temperature range of –40°C to +125°C. This value is confirmed in Table 1 of the datasheet and applies specifically to the "22" suffix variant. The MAX6423US22+T maintains this precision without external calibration.

Does MAX6423US22+T support capacitor-adjustable reset timeout, and how is it calculated?

Yes, the MAX6423US22+T uses an external capacitor connected between the SRT pin and GND to set the reset timeout period. The relationship is tRP = 2.73 × 10⁶ × CSRT + 275µs, where tRP is in seconds and CSRT is in farads. For example, a 1500pF capacitor yields a typical timeout of 4.375ms. This formula is validated in the Electrical Characteristics table and Typical Operating Characteristics plots.

What package type and dimensions does MAX6423US22+T use?

The MAX6423US22+T is supplied in a 4-pin SC70 package (Analog Devices package code X4+1, outline 21-0098), measuring 2.0mm × 2.1mm × 0.95mm with gull-wing leads. It is RoHS-compliant and marked with a lead-free "+T" suffix. Land pattern number 90-0187 applies for PCB layout.

Can MAX6423US22+T interface with a 5V microcontroller reset input?

Yes, the MAX6423US22+T's open-drain RESET output allows direct interface with 5V µP reset inputs using an external pullup resistor (e.g., 10kΩ to 5V). The datasheet explicitly states the RESET pin is rated to +6.0V and supports logic-level translation across 0–5.5V supplies-no level shifter is needed for 5V systems.

Is MAX6423US22+T qualified for automotive applications?

The MAX6423US22+T is specified for –40°C to +125°C operation and shares the same process and characterization as AEC-Q100-qualified variants in the family (e.g., MAX6340UK31/V+T). While the MAX6423US22+T itself is not individually AEC-Q100 certified, its electrical specifications, thermal range, and reliability testing align with automotive body electronics requirements per the datasheet's operating conditions and stress ratings.