Analog Devices Inc./Maxim Integrated MAX6340UK44+T

Overview

MAX6340UK44+T from Analog Devices is a low-power microprocessor supervisor IC with open-drain active-low reset output, 4.375V nominal reset threshold (±2.5% over temperature), capacitor-adjustable reset timeout (3.0–5.75ms at CSRT = 1500pF), 1.6µA typical supply current, and guaranteed operation down to VCC = 1V. It monitors system supply voltage in portable, automotive, and medical equipment to prevent erroneous µP startup during brownout.

For engineers reviewing the MAX6340UK44+T datasheet, MAX6340UK44+T pinout, MAX6340UK44+T application, or MAX6340UK44+T equivalent, key selection criteria include reset threshold accuracy, open-drain logic compatibility with multiple supply rails, capacitor-set timeout flexibility, immunity to short VCC transients, and AEC-Q100 qualification eligibility (per MAX6340UK31/V+T variant).

Technical Context

The MAX6340UK44+T implements a precision voltage detector with laser-trimmed internal resistors setting a 4.375V reset threshold, referenced to an internal 0.65V bandgap. Its SRT pin sources a 240nA ramp current into an external capacitor to generate a programmable reset timeout period.

Reset assertion occurs when VCC falls below the threshold; deassertion requires both VCC rise above threshold and full capacitor ramp to 0.65V. The open-drain RESET output supports wired-OR configurations and pullup to any rail ≤5.5V, enabling interoperability across mixed-voltage µP systems.

Key Specifications

Pinout & Package

MAX6340UK44+T is housed in a 5-pin SOT23-5 package with exposed pad (not electrically connected), 1.3mm height, and RoHS-compliant lead-free finish (+T suffix). Pin 3 is internally unconnected (N.C.) and must be left floating or tied to GND per layout best practice.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NCP302LSN43T1G and TLV809K33DBZR, MAX6340UK44+T uniquely combines 4.375V precision threshold, capacitor-programmable timeout, and open-drain output in a 5-pin SOT23 - enabling design reuse across voltage domains and timing requirements without layout changes.

Availability

MAX6340UK44+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-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6340UK44+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 MAX6340 series belongs to Analog Devices' precision voltage supervisor product line, engineered for ultra-low-power, high-accuracy reset generation in space-constrained and battery-sensitive applications.

FAQ

What is the exact reset threshold voltage of MAX6340UK44+T?

The MAX6340UK44+T features a factory-laser-trimmed nominal reset threshold of 4.375V, with ±1.5% accuracy at +25°C and ±2.5% over the full -40°C to +125°C operating range. This value is confirmed in the Electrical Characteristics table of the official Analog Devices datasheet (Rev 11, 9/24), where "44" in the part number directly references the 4.375V threshold per Table 1.

Does MAX6340UK44+T support capacitor-adjustable reset timeout, and how is it calculated?

Yes, MAX6340UK44+T supports capacitor-adjustable reset timeout via the SRT pin. The timeout period tRP (in seconds) is calculated as tRP = (2.73 × 10⁶) × CSRT + 275µs, where CSRT is the capacitor value in farads. For example, a 1500pF capacitor yields a typical timeout of 4.375ms, as verified in the datasheet's Electrical Characteristics table under "Reset Timeout Period".

What is the function of Pin 3 (N.C.) on MAX6340UK44+T, and how should it be handled?

Pin 3 of MAX6340UK44+T is Not Connected (N.C.) - it has no internal connection and serves no electrical function. Per the datasheet's Pin Description and Layout Considerations sections, it may be left floating or tied to GND for mechanical stability and solder joint reliability; neither choice affects electrical performance.

Can MAX6340UK44+T drive a 5V-tolerant µP reset input directly?

No - MAX6340UK44+T has an open-drain RESET output and cannot actively drive high. It requires an external pullup resistor (typically 10kΩ–100kΩ) to the target logic rail (e.g., 5V, 3.3V, or 1.8V). This configuration is explicitly validated in the datasheet's "Interfacing to Other Voltages for Logic Compatibility" section and Figure 1.

Is MAX6340UK44+T qualified for automotive applications?

The MAX6340UK44+T itself is not explicitly AEC-Q100 qualified per the datasheet; however, the MAX6340UK31/V+T variant is listed as AEC-Q100 qualified. While MAX6340UK44+T shares identical architecture, package, and process (BiCMOS), qualification status is part-number-specific. For automotive designs, engineers must select the designated qualified variant or obtain formal qualification confirmation from Analog Devices.