Analog Devices Inc./Maxim Integrated MAX6412UK44-T

Overview

MAX6412UK44-T from Maxim Integrated is a low-power microprocessor reset supervisor IC with fixed 4.375V VCC reset threshold, manual reset input (MR), and capacitor-adjustable reset timeout delay. It features active-low push-pull RESET output, guaranteed valid operation down to VCC = 1V, and operates across –40°C to +125°C in SOT23-5 package. It is used for reliable power-on reset and brownout protection in battery-powered controllers and embedded systems.

For engineers reviewing the MAX6412UK44-T datasheet, MAX6412UK44-T pinout, MAX6412UK44-T application, or MAX6412UK44-T equivalent, key selection criteria include its factory-trimmed 4.375V threshold accuracy (±2.5% over temperature), 1.7µA typical quiescent current, capacitor-programmable timeout (275µs base + 2.71×10⁶ × CSRT), manual reset support, and automotive-grade temperature range.

Technical Context

The MAX6412UK44-T implements a precision voltage comparator with laser-trimmed resistors to monitor VCC against a fixed 4.375V threshold (per Table 1 suffix "44"), plus a high-impedance MR input that asserts reset when pulled low. Reset assertion is synchronized to VCC crossing the threshold or MR activation, with deassertion delayed by an externally set timeout period generated via a 240nA current source charging the SRT capacitor to a 0.65V internal reference.

Its push-pull RESET output drives logic-compatible levels: VOL ≤ 0.4V at ISINK = 3.2mA (VCC ≥ 4.5V) and VOH ≥ 0.8×VCC at ISOURCE = 800µA, ensuring robust interface with µP reset inputs. The device guarantees valid reset signaling even as VCC drops to 1V, and includes built-in immunity to short negative-going transients on VCC (e.g., ≤50µs for 100mV overdrive).

Key Specifications

Pinout & Package

MAX6412UK44-T is housed in a 5-pin SOT23-5 surface-mount package (outline U5-2, land pattern 90-0174), with gull-wing leads and RoHS-compliant lead-free finish (denoted by "+T" variant; standard "-T" is leaded).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6412UK44-T, MAX6326UT44D3+ offers open-drain flexibility but sacrifices MR functionality and doubles quiescent current, while TPS3808G33DBVR provides lower ICC but mismatches the required 4.375V threshold and demands board-level changes.

Availability

MAX6412UK44-T is available at Aetrix Electronics and suitable for automotive body control modules, portable medical monitors, industrial PLC I/O modules, smart energy meters, and battery-powered embedded controllers requiring stable component supply across extended temperature ranges.

Supply support for MAX6412UK44-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

Maxim Integrated (now part of Analog Devices) designs precision analog and mixed-signal ICs for demanding industrial, automotive, and computing applications.

The MAX6412–MAX6420 family delivers ultra-low-power, capacitor-programmable reset supervision for systems requiring accurate voltage monitoring and flexible timeout control in harsh thermal environments.

FAQ

What is the exact reset threshold voltage of MAX6412UK44-T?

The MAX6412UK44-T has a factory-trimmed VCC reset threshold of 4.375V, with tolerance of ±2.5% over the full operating temperature range (–40°C to +125°C). This value is confirmed in Table 1 of the datasheet (suffix "44") and verified in the Electrical Characteristics table under "VCC Reset Threshold Accuracy". The threshold is laser-trimmed and does not require external calibration.

How do I calculate the reset timeout period for MAX6412UK44-T?

The reset timeout period tRP for MAX6412UK44-T is calculated using tRP = (2.71 × 10⁶) × CSRT + 275µs, where CSRT is the capacitor value in farads connected between SRT and GND. For example, a 1500pF capacitor yields tRP ≈ 4.375ms. The formula is derived from the 240nA internal ramp current charging CSRT to a 0.65V reference, and is validated in the Typical Operating Characteristics (Figure 3).

Does MAX6412UK44-T support manual reset functionality?

Yes, MAX6412UK44-T supports manual reset via its MR pin (Pin 3), which is internally pulled up to VCC with a 20kΩ resistor. Asserting MR low initiates reset, and the RESET output remains active for the full timeout period after MR is released. No external components are required - a normally open momentary switch from MR to GND suffices, as confirmed in the "Manual Reset Input" section of the datasheet.

What is the recommended capacitor type for the SRT pin on MAX6412UK44-T?

The SRT pin on MAX6412UK44-T requires a low-leakage capacitor (<10nA) with stable dielectric characteristics over temperature. Ceramic capacitors (X7R or C0G/NP0) are explicitly recommended in the datasheet's "Selecting a Reset Capacitor" section. Avoid electrolytic or high-leakage film types, as leakage current directly impacts timeout accuracy; stray capacitance or probe loading on SRT must also be minimized per Layout Considerations.

Is MAX6412UK44-T suitable for automotive applications?

Yes, MAX6412UK44-T is fully specified for operation from –40°C to +125°C and is listed in the Ordering Information table with "-40°C to +125°C" temperature range. While not explicitly labeled "AEC-Q100 automotive qualified" in this revision, its extended temperature rating, power-supply transient immunity, and qualification for use in automotive systems (cited in Applications section) make it suitable for non-safety-critical automotive subsystems like body control and infotainment. For ASIL-B/C applications, consult latest Maxim/Analog Devices automotive qualification status separately.