Analog Devices Inc./Maxim Integrated MAX6414UK44

Overview

MAX6414UK44 from Maxim Integrated is a low-power, single-voltage microprocessor reset supervisor IC with factory-trimmed 4.375V VCC reset threshold, active-low open-drain RESET output, manual reset input (MR), and capacitor-adjustable reset timeout delay. It monitors supply voltage in battery-powered controllers and embedded systems, asserting reset during brownout or power-up until the external SRT capacitor discharges to 0.65V.

For engineers reviewing the MAX6414UK44 datasheet, MAX6414UK44 pinout, MAX6414UK44 application, or MAX6414UK44 equivalent, key selection criteria include its guaranteed reset validity down to VCC = 1V, 1.7µA typical quiescent current, SOT23-5 package compatibility, and open-drain output enabling level-shifting across 0–5.5V logic domains.

Technical Context

The MAX6414UK44 implements a precision bandgap-based voltage comparator for VCC monitoring and a 240nA constant-current ramp generator tied to the SRT pin. Reset assertion occurs when VCC falls below 4.375V ±2.5% or MR is pulled low; deassertion requires both VCC > 4.375V and SRT capacitor voltage ≥0.65V after timeout.

Its open-drain RESET output uses an NMOS pull-down stage with <0.4V VOL at 3.2mA sink, requiring an external pull-up for logic-high assertion. The internal 20kΩ MR pull-up resistor enables direct switch-to-ground connection without external components.

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 reset supervision applications.

Compared with MAX6414UK44, MAX6414UK43-T offers tighter threshold alignment for 4.3V rails but identical functionality, while TLV809K33DBZR reduces size and cost at the expense of manual reset capability and programmable timeout - critical for robust industrial startup sequences.

Availability

MAX6414UK44 is available at Aetrix Electronics and suitable for battery-powered controllers, automotive body electronics, and medical infusion pumps requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6414UK44 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 low power, high reliability, and wide temperature operation.

The MAX6412–MAX6420 product line delivers configurable microprocessor reset supervision with capacitor-adjustable timing, targeting applications where deterministic power-on reset behavior and ultra-low quiescent current are essential.

FAQ

What is the exact reset threshold voltage for MAX6414UK44?

The MAX6414UK44 has a factory-trimmed VCC reset threshold of 4.375V, with ±2.5% tolerance over the full -40°C to +125°C operating range. This value is confirmed in Table 1 of the datasheet (suffix "44") and Electrical Characteristics section, where it appears as the typical value within the 4.266V–4.484V min/max band. The MAX6414UK44 uses laser-trimmed resistors to achieve this precision without external components.

How do I calculate the reset timeout capacitor value for MAX6414UK44?

To set a desired reset timeout period (tRP) for MAX6414UK44, use the formula CSRT = (tRP − 275µs) / 2.71×10⁶, where tRP is in seconds and CSRT is in farads. For example, a 100ms timeout requires CSRT = (0.1 − 0.000275) / 2.71×10⁶ ≈ 36.8nF. The MAX6414UK44 datasheet specifies ceramic capacitors with <10nA leakage for best accuracy, and the SRT pin must be routed short and away from noisy traces.

Does MAX6414UK44 support manual reset functionality?

Yes, MAX6414UK44 includes a dedicated MR (manual reset) pin (Pin 3) that asserts reset when pulled low. It features an internal 20kΩ pull-up resistor, allowing direct connection of a normally-open momentary switch between MR and ground. Reset remains active for the full capacitor-programmed timeout period after the switch is released, eliminating need for external debounce circuitry in most applications.

What is the purpose of the open-drain RESET output on MAX6414UK44?

The open-drain RESET output (Pin 1) on MAX6414UK44 enables level-shifting across different voltage domains: it can interface with µPs powered from 1.8V, 3.3V, or 5V supplies by using an external pull-up resistor to the target logic rail. This avoids level translators and simplifies design in multi-voltage systems. The MAX6414UK44 itself operates from VCC (up to 5.5V), while RESET can safely sink current into any supply ≤5.5V.

Can MAX6414UK44 operate reliably at VCC = 1.2V?

Yes, MAX6414UK44 guarantees valid reset output behavior down to VCC = 1.0V, as stated in the Electrical Characteristics table ("Guaranteed Reset Valid to VCC = 1V"). At 1.2V, the device draws ~2.0µA (per typical supply current vs. voltage curve), maintains accurate 4.375V threshold detection relative to VCC, and sustains proper SRT capacitor charging. However, open-drain RESET cannot drive high without an external pull-up, and VOL remains <0.3V at 500µA sink.