Analog Devices Inc./Maxim Integrated MAX6414UK18+

Overview

MAX6414UK18+ from Maxim Integrated is a low-power microprocessor supervisor IC with fixed 1.8V VCC reset threshold, manual reset input (MR), and active-low open-drain RESET output. It monitors supply voltage in battery-powered controllers and embedded systems, asserts reset during brownout or power-up, and provides capacitor-adjustable timeout (275µs to 5.75ms). Operating from -40°C to +125°C, it guarantees valid reset down to VCC = 1V.

For engineers reviewing the MAX6414UK18+ datasheet, MAX6414UK18+ pinout, MAX6414UK18+ application, or MAX6414UK18+ equivalent, key selection criteria include its SOT23-5 package, 1.8V ±2.5% threshold accuracy, 1.7µA typical quiescent current at 2V, open-drain output compatibility with mixed-voltage µPs, and AEC-Q100 qualification for automotive use.

Technical Context

The MAX6414UK18+ implements a precision bandgap-based voltage comparator for VCC monitoring and a dedicated manual reset input with internal 20kΩ pullup. Its reset timeout is set by an external capacitor on the SRT pin, driven by a 240nA ramp current source referenced to 0.65V.

It features guaranteed reset assertion validity down to VCC = 1V, power-supply transient immunity (e.g., 100mV overdrive tolerates ≤50µs glitches), and hysteresis of 4×VTH (≈7.2mV at 1.8V) to prevent chatter near threshold. The open-drain RESET output supports logic-level translation up to 5.5V via external pullup.

Key Specifications

Pinout & Package

SOT23-5 package: ultra-compact 2.9mm × 1.6mm surface-mount footprint with 0.95mm pitch, optimized for space-constrained portable and automotive PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6414UK18+, MAX6316LUK18+T omits manual reset for reduced complexity, while TPS3808G18DBVR trades temperature range and AEC-Q100 qualification for lower IQ - making MAX6414UK18+ optimal for high-reliability, thermally demanding designs requiring both automatic and manual reset.

Availability

MAX6414UK18+ is available at Aetrix Electronics and suitable for automotive body electronics, portable medical devices, industrial PLC modules, and smart energy metering systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6414UK18+ 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 demanding industrial, automotive, and medical applications, emphasizing reliability, low power, and high integration.

The MAX6412–MAX6420 family delivers configurable µP supervision with flexible reset timing and dual-voltage monitoring, targeting systems where deterministic power-up sequencing and brownout resilience are critical.

FAQ

What is the exact reset threshold voltage of the MAX6414UK18+?

The MAX6414UK18+ has a factory-trimmed VCC reset threshold of 1.800V, with ±2.5% accuracy over the full -40°C to +125°C temperature range. At +25°C, the tolerance tightens to ±1.25%, meaning the actual threshold falls between 1.7775V and 1.8225V. This value is laser-trimmed during production and documented in Table 1 of the datasheet under suffix "18".

How do I calculate the capacitor value for a 4.0ms reset timeout with the MAX6414UK18+?

Use the formula CSRT = (tRP − 275µs) / 2.71×10⁶, where tRP = 4.0ms = 0.004s. Substituting gives CSRT = (0.004 − 0.000275) / 2,710,000 ≈ 1375pF. A standard 1500pF ceramic capacitor yields ~4.375ms (within datasheet spec), and a 1200pF capacitor yields ~3.625ms - both acceptable for most µP requirements.

Does the MAX6414UK18+ require an external pullup resistor on the RESET pin?

Yes, the MAX6414UK18+ has an active-low open-drain RESET output and requires an external pullup resistor to establish a defined logic-high state when deasserted. A 10kΩ resistor to the target µP's I/O voltage (e.g., 3.3V or 5V) is typical. The datasheet confirms RESET leakage current is ≤1.0µA, ensuring minimal voltage drop across reasonable pullup values.

Is the MAX6414UK18+ qualified for automotive applications?

The base MAX6414UK18+ is not automotive-qualified, but the /V variant - MAX6414UK18/V+T - is AEC-Q100 qualified for Grade 0 (−40°C to +150°C junction) and intended for automotive use. This version undergoes additional stress testing and is marked with "/V" in the ordering code. Always verify the specific part number's qualification status in the official Maxim/Analog Devices ordering information table.

What is the maximum allowable leakage current for the SRT capacitor in the MAX6414UK18+?

The SRT capacitor in the MAX6414UK18+ must exhibit leakage current <10nA to prevent timing errors, as the internal 240nA ramp current charges it. Ceramic capacitors (e.g., X7R, C0G) meet this requirement and are explicitly recommended in the datasheet. Tantalum or electrolytic types are unsuitable due to higher leakage, which would extend the timeout beyond specification.