Analog Devices Inc./Maxim Integrated MAX6423US26+T

Overview

MAX6423US26+T from Analog Devices is a low-power microprocessor supervisor IC with open-drain active-low reset output, 2.625V ±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 MAX6423US26+T datasheet, MAX6423US26+T pinout, MAX6423US26+T application, or MAX6423US26+T equivalent, key selection criteria include its SC70-4 package, 1.6µA typical quiescent current, open-drain logic compatibility with multiple supply rails, and immunity to sub-50µs VCC transients at 100mV overdrive.

Technical Context

The MAX6423US26+T implements a precision voltage detector using laser-trimmed resistors to set its 2.625V reset threshold with ±2.5% accuracy over –40°C to +125°C. Its reset assertion is triggered by VCC falling below threshold and held for a user-defined timeout period determined by an external SRT-to-ground capacitor.

Internally, a 240nA current source charges the SRT capacitor; reset deassertion occurs when the ramp voltage reaches 0.65V. The open-drain RESET output requires an external pullup and remains valid for VCC ≥ 1V, enabling reliable µP reset coordination across diverse logic families.

Key Specifications

Pinout & Package

MAX6423US26+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 compatible with standard reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6423US26+T, the MAX6423US26D+ offers identical electrical behavior in a different package, while TLV803EB26DBZR trades timing adjustability for ultra-low current and smaller footprint-making it suitable only where fixed delay is acceptable and layout density is critical.

Availability

MAX6423US26+T is available at Aetrix Electronics and suitable for portable equipment, battery-powered controllers, and automotive body electronics requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6423US26+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.

The MAX6421–MAX6426 family was designed specifically for low-power, precision voltage supervision in space-constrained, battery-sensitive applications where adjustable reset timing and robust transient immunity are essential.

FAQ

What is the exact reset threshold voltage of the MAX6423US26+T?

The MAX6423US26+T features a factory-laser-trimmed reset threshold of 2.625V with ±2.5% accuracy over the full –40°C to +125°C temperature range. This value is confirmed in Table 1 of the datasheet under suffix "26", and applies specifically to the MAX6423US26+T variant-not the broader MAX6423 family.

Does the MAX6423US26+T require an external capacitor to function?

The MAX6423US26+T operates as a basic voltage detector without an external capacitor by floating the SRT pin, delivering ~275µs reset timeout. However, to achieve longer, user-defined timeouts (up to 5.75ms), a capacitor must be connected between SRT and GND per the formula tRP = 2.73×10⁶ × CSRT + 275µs. Ceramic capacitors <10nA leakage are recommended.

Can the MAX6423US26+T drive a 3.3V microcontroller reset input directly?

Yes-the MAX6423US26+T's open-drain RESET output can interface directly with a 3.3V µP reset input when paired with a 3.3V pullup resistor (e.g., 10kΩ). The device guarantees VOL ≤ 0.3V at ISINK = 500µA when VCC ≥ 1.8V, ensuring solid logic-low assertion, and VOH = 0.8×VCC when sourcing 1µA, allowing clean high-state definition via the external rail.

What package type is used for the MAX6423US26+T?

The MAX6423US26+T uses a 4-pin SC70 package (Analog Devices package code X4+1, outline 21-0098), with dimensions 2.0mm × 2.1mm × 0.95mm. This differs from the SOT143 variant (MAX6423US26+T with "US" prefix denotes SOT143; "XS" denotes SC70-but per Ordering Information table, MAX6423US26+T is explicitly listed under SOT143-4, confirming US = SOT143).

Is the MAX6423US26+T qualified for automotive applications?

The MAX6423US26+T itself is not individually AEC-Q100 qualified, but belongs to the MAX6340/MAX6421–MAX6426 family, within which the MAX6340UK31/V+T variant is explicitly AEC-Q100 qualified. The MAX6423US26+T shares identical process (BiCMOS), design, and operating temperature range (–40°C to +125°C), and is widely deployed in automotive body electronics-though formal qualification applies only to designated part numbers.