Analog Devices Inc./Maxim Integrated MAX6423US31+

Overview

MAX6423US31+ from Maxim Integrated is a low-power microprocessor supervisor IC that monitors 3.075V system supply voltage and asserts an active-low open-drain reset signal during undervoltage conditions. It features capacitor-adjustable reset timeout (2.73×10⁶ × C_SRT + 275µs), guaranteed operation down to V_CC = 1V, and 1.6µA typical quiescent current. It is used in battery-powered controllers to prevent code execution errors during brownout.

For engineers reviewing the MAX6423US31+ datasheet, MAX6423US31+ pinout, MAX6423US31+ application, or MAX6423US31+ equivalent, this page delivers verified electrical parameters, package mapping to SOT143-4, confirmed open-drain RESET behavior, temperature-stable threshold accuracy (±2.5% over –40°C to +125°C), and real-world timing characteristics for embedded µP reset design.

Technical Context

The MAX6423US31+ implements a precision voltage detector with laser-trimmed internal resistors setting a nominal 3.075V reset threshold (suffix "31"), ±2.5% over full temperature range. Its SRT pin hosts a 240nA constant-current ramp source charging an external capacitor to generate the reset timeout delay.

It uses open-drain RESET output requiring an external pullup, supports logic-level interfacing up to 5.5V, and maintains valid reset assertion down to V_CC = 1V. Immunity to short V_CC transients is confirmed via maximum transient duration vs. threshold overdrive curves.

Key Specifications

Pinout & Package

MAX6423US31+ is packaged in a 4-pin SOT143-4 (U4+1) surface-mount package, 1.3mm × 2.1mm footprint, 0.95mm height, lead-free (RoHS-compliant).

Key Features

Applications

Equivalent & Alternatives

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

Compared with NCP302LSN30T1G and TLV809K33DBZR, MAX6423US31+ offers field-configurable timeout, tighter threshold accuracy (±2.5% vs. ±3%), and open-drain output enabling robust reset bus architecture - critical for systems requiring precise brownout response and multi-source reset coordination.

Availability

MAX6423US31+ is available at Aetrix Electronics and suitable for battery-powered controllers, automotive body electronics, and medical infusion pumps requiring stable component supply with long-term lifecycle assurance.

Supply support for MAX6423US31+ 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 power, sensing, and interface applications in industrial, automotive, and medical markets.

The MAX642x series targets ultra-low-power microprocessor supervision in space-constrained, battery-sensitive systems - delivering accurate voltage monitoring, flexible reset timing, and robust noise immunity in minimal footprints.

FAQ

What is the exact reset threshold voltage of MAX6423US31+?

The MAX6423US31+ has a nominal reset threshold of 3.075V, with factory laser trimming per Table 1 suffix "31". The specification guarantees ±2.5% accuracy over the full operating temperature range (–40°C to +125°C), meaning the actual threshold falls between 2.998V and 3.152V under worst-case conditions. This value is measured at V_CC = 1.6V to 5V and is stable across temperature and supply voltage.

Does MAX6423US31+ support adjustable reset timeout, and how is it configured?

Yes, MAX6423US31+ supports capacitor-adjustable reset timeout via the SRT pin. Connect an external capacitor (C_SRT) between SRT and GND. The timeout period t_RP (in seconds) is calculated as t_RP = 2.73 × 10⁶ × C_SRT + 275µs, where C_SRT is in farads. For example, a 1500pF capacitor yields ~4.375ms typical timeout. Ceramic capacitors with leakage <10nA are recommended.

What package type and pin count does MAX6423US31+ use?

MAX6423US31+ is supplied in a 4-pin SOT143-4 package (package code U4+1), measuring 1.3mm × 2.1mm with 0.95mm height. Pinout is: Pin 1 = V_CC, Pin 2 = GND, Pin 3 = RESET (open-drain), Pin 4 = SRT. This matches the SC70/SOT143 footprint family and is distinct from the 5-pin SOT23 variants like MAX6425.

Can MAX6423US31+ drive a 5V microcontroller reset input?

Yes, MAX6423US31+ can interface with 5V µP reset inputs because its open-drain RESET output is rated to 5.5V. Simply connect an external pullup resistor (e.g., 10kΩ) from the RESET pin to the 5V supply. When asserted, RESET pulls low to ≤0.4V (at 3.2mA sink); when deasserted, the pullup brings it to 5V - ensuring full logic-level compatibility without level shifters.

Is MAX6423US31+ qualified for automotive applications?

No - MAX6423US31+ is not AEC-Q100 qualified. Only the MAX6340UK31/V+T variant (same threshold, 5-pin SOT23) carries AEC-Q100 Grade 2 qualification (–40°C to +105°C). MAX6423US31+ operates from –40°C to +125°C but lacks automotive stress testing and documentation. For automotive body control modules, MAX6340UK31/V+T is the qualified alternative.