Analog Devices Inc./Maxim Integrated MAX6423XS26+T

Overview

MAX6423XS26+T from Analog Devices is a low-power microprocessor supervisor IC with active-low open-drain reset output, 2.625V ±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 supply voltage in portable and battery-powered systems to prevent code-execution errors during power-up, brownout, or power-down.

For engineers reviewing the MAX6423XS26+T datasheet, MAX6423XS26+T pinout, MAX6423XS26+T application, or MAX6423XS26+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 below 100mV overdrive.

Technical Context

The MAX6423XS26+T implements a precision voltage-detection architecture using laser-trimmed resistors and a 0.65V internal reference. Its SRT pin hosts a 240nA constant-current ramp source that charges an external capacitor to set the reset timeout period via dV/dt = I/C.

Reset assertion occurs when VCC falls below 2.625V (±2.5% over −40°C to +125°C), with 80µs propagation delay on VCC fall. The open-drain RESET output requires an external pullup and remains valid for VCC ≥ 1V, supporting wired-OR configurations with auxiliary reset sources.

Key Specifications

Pinout & Package

MAX6423XS26+T is housed in a 4-pin SC70-4 package (package code X4+1, outline 21-0098), measuring 1.25mm × 0.85mm × 0.55mm, with wettable flanks and RoHS-compliant lead-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6423XS26+T, the MAX6423US26+T offers identical supervision functionality in a mechanically distinct but electrically interchangeable package, while the NCP302LS26T1G trades adjustable timeout and open-drain versatility for lower cost and simpler implementation in fixed-timing applications.

Availability

MAX6423XS26+T is available at Aetrix Electronics and suitable for battery-powered medical sensors, automotive body control modules, and industrial handheld terminals requiring stable component supply, long-lifecycle assurance, and RoHS-compliant packaging.

Supply support for MAX6423XS26+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 MAX6423XS26+T belongs to the MAX6340/MAX6421–MAX6426 family of low-power microprocessor supervisors, designed specifically for reliable power-monitoring in space-constrained, battery-sensitive, and thermally demanding embedded systems.

FAQ

What is the exact reset threshold voltage of the MAX6423XS26+T?

The MAX6423XS26+T has a factory-trimmed nominal reset threshold of 2.625V, with tolerance of ±2.5% over the full −40°C to +125°C temperature range. This value is laser-trimmed during production and specified in the Electrical Characteristics table under VTH parameter. The '26' suffix in MAX6423XS26+T directly denotes this 2.625V threshold per Table 1 in the datasheet.

Does the MAX6423XS26+T require an external capacitor to function?

The MAX6423XS26+T does not require an external capacitor to assert reset - it will trigger immediately upon VCC falling below 2.625V. However, a capacitor on the SRT pin is required to achieve the full reset timeout delay (e.g., 3.0–5.75ms with 1500pF). Without it, the timeout defaults to 275µs. The device remains fully functional with or without the capacitor, depending on system timing needs.

Can the MAX6423XS26+T drive a reset line directly without a pullup resistor?

No - the MAX6423XS26+T features an open-drain RESET output and cannot drive high without an external pullup resistor. A 10kΩ to 100kΩ resistor to any supply between 0V and 5.5V is required to establish a valid logic-high state. This architecture enables level translation and wired-OR reset sharing, but omission of the pullup results in floating or indeterminate reset logic levels.

Is the MAX6423XS26+T qualified for automotive applications?

The MAX6423XS26+T itself is not AEC-Q100 qualified; only the MAX6340UK31/V+T variant in the same family carries AEC-Q100 Grade 2 qualification. However, MAX6423XS26+T operates across −40°C to +125°C and is widely used in automotive body electronics where full qualification is not mandated, provided system-level validation confirms robustness under vehicle-specific stress conditions.

How does the MAX6423XS26+T handle VCC transients during operation?

The MAX6423XS26+T is immune to short negative-going VCC transients up to 50µs in duration when the overdrive is ≤100mV below the 2.625V threshold. This behavior is characterized in the "Maximum Transient Duration vs. Reset Threshold Overdrive" graph. Transients exceeding this limit will trigger reset, ensuring protection against sustained brownout while ignoring benign noise spikes.