Analog Devices Inc./Maxim Integrated MAX6426UK46+T

Overview

MAX6426UK46+T from Analog Devices is a low-power microprocessor supervisor IC with open-drain active-low reset output, 4.625V ±2.5% factory-trimmed reset threshold, capacitor-adjustable reset timeout (3.0–5.75ms with 1500pF), and guaranteed operation down to VCC = 1V. It monitors system supply voltage in portable, automotive, and medical equipment to prevent erroneous µP execution during brownout.

For engineers reviewing the MAX6426UK46+T datasheet, MAX6426UK46+T pinout, MAX6426UK46+T application, or MAX6426UK46+T equivalent, key selection criteria include its SOT23-5 open-drain RESET output, 1.6µA typical quiescent current, -40°C to +125°C operating range, and compatibility with wired-OR reset architectures requiring external pullup.

Technical Context

The MAX6426UK46+T implements a precision voltage detector using laser-trimmed resistors to set its 4.625V reset threshold with ±2.5% accuracy over temperature. Its reset assertion logic responds to VCC falling below threshold with 80µs propagation delay and holds RESET low for a user-defined timeout period determined by an external capacitor on the SRT pin.

A 240nA internal ramp current charges the SRT capacitor to a 0.65V internal reference; deassertion occurs when that voltage is reached. The open-drain RESET output supports logic-level translation up to 5.5V and enables wired-OR configurations with auxiliary reset sources.

Key Specifications

Pinout & Package

MAX6426UK46+T is housed in a RoHS-compliant 5-pin SOT23-5 package (outline 21-0057) with 0.95mm pitch, designed for reflow soldering and automated assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PST9246 and NCP302HS46T1G, the MAX6426UK46+T uniquely combines AEC-Q100 readiness, proven transient immunity, and open-drain flexibility-making it the preferred choice for automotive and safety-critical portable designs where reset reliability and architectural adaptability are non-negotiable.

Availability

MAX6426UK46+T is available at Aetrix Electronics and suitable for automotive body control modules, portable medical devices, industrial PLC expansion cards, and set-top box power management units requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6426UK46+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 MAX6426UK46+T belongs to the MAX6340/MAX6421–MAX6426 family of ultra-low-power voltage supervisors, engineered specifically for robust reset generation in battery-constrained and thermally demanding embedded systems.

FAQ

What is the exact reset threshold voltage of the MAX6426UK46+T?

The MAX6426UK46+T features a factory-laser-trimmed reset threshold of 4.625V with ±2.5% accuracy over the full -40°C to +125°C operating temperature range. This value is confirmed in the Electrical Characteristics table of the official Analog Devices datasheet (Rev 11, p.2), where VTH is specified as 4.509V (min), 4.625V (typ), and 4.741V (max) at TA = -40°C to +125°C.

Does the MAX6426UK46+T support wired-OR reset functionality?

Yes, the MAX6426UK46+T supports wired-OR reset through its open-drain RESET output. As documented in the Applications Information section (p.5), an external open-drain logic signal can be directly connected to the RESET pin to hold the system in reset. This configuration is explicitly illustrated in Figure 2 of the datasheet and requires no additional components beyond a shared pullup resistor.

What capacitor value sets a 4.375ms reset timeout for the MAX6426UK46+T?

A 1500pF capacitor on the SRT pin yields a nominal 4.375ms reset timeout for the MAX6426UK46+T, as stated in the Electrical Characteristics table (p.2) under "Reset Timeout Period" with condition CSRT = 1500pF. The relationship is linear: tRP = 2.73 × 10⁶ × CSRT + 275µs, so 1500pF produces exactly the typical value shown in the datasheet.

Is the MAX6426UK46+T qualified for automotive applications?

No-the MAX6426UK46+T itself is not AEC-Q100 qualified. Only the MAX6340UK31/V+T variant in this family carries AEC-Q100 qualification (as noted in the Benefits and Features section, p.1). The MAX6426UK46+T shares the same process and package but lacks formal automotive qualification documentation and testing evidence per the published datasheet.

Can the MAX6426UK46+T operate reliably below 1.6V supply voltage?

Yes-the MAX6426UK46+T guarantees functional reset assertion down to VCC = 1.0V, as specified in the Absolute Maximum Ratings (p.2) and Electrical Characteristics (p.2, "Supply Voltage Range"). Its reset output remains valid and its internal comparator operates correctly at 1.0V, though quiescent current rises to 2.5µA (max) at VCC ≤ 2.0V per the ICC specifications.