Analog Devices Inc./Maxim Integrated MAX6412UK42+T

Overview

The MAX6412UK42+T from Maxim Integrated is a low-power microprocessor supervisor IC with fixed 4.2V VCC reset threshold, manual reset input (MR), and active-low push-pull reset output. It monitors supply voltage in systems from 1.6V to 5V, asserts reset during brownout or power-up, and guarantees valid reset down to VCC = 1V. Used in automotive ECUs and battery-powered controllers for reliable power-on initialization.

For engineers reviewing the MAX6412UK42+T datasheet, MAX6412UK42+T pinout, MAX6412UK42+T application, or MAX6412UK42+T equivalent, key selection criteria include its factory-trimmed 4.2V threshold (±2.5% over -40°C to +125°C), capacitor-adjustable reset timeout (275µs to 5.75ms), 1.7µA typical quiescent current at 1.8V, SOT23-5 package, and AEC-Q100-qualified variants.

Technical Context

The MAX6412UK42+T implements a precision bandgap-based voltage comparator for VCC monitoring and a dedicated MR input with internal 20kΩ pullup. Its reset timeout is generated by a 240nA current source charging an external capacitor on the SRT pin, referenced to a stable 0.65V internal threshold.

It features guaranteed reset assertion during VCC ramp-down below 4.2V (with 4.3mV hysteresis), 20ns MR-to-RESET delay, and immunity to transients ≤50µs when VCC dips 100mV below threshold - enabling robust operation in noisy automotive and industrial environments.

Key Specifications

Pinout & Package

SOT23-5 package: 2.9mm × 1.6mm × 1.1mm body, gull-wing leads, RoHS-compliant lead-free finish (+T suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6412UK42+T, MAX6326UR42+T eliminates capacitor dependency but sacrifices timeout flexibility and MR functionality, while TPS3808G33DBVR shifts threshold and adds features at the cost of pin count and layout compatibility.

Availability

MAX6412UK42+T is available at Aetrix Electronics and suitable for automotive engine control units, portable medical monitors, and industrial PLC I/O modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6412UK42+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 MAX6412UK42+T belongs to the MAX6412–MAX6420 family of low-power µP supervisors engineered for reliable power sequencing and brownout protection in safety-critical embedded systems.

FAQ

What is the exact reset threshold voltage of the MAX6412UK42+T and how tightly is it specified?

The MAX6412UK42+T has a nominal VCC reset threshold of 4.200V, with ±1.25% accuracy at +25°C and ±2.5% over the full -40°C to +125°C operating range. This is factory-laser-trimmed and verified per Table 1 in the datasheet, where suffix "42" corresponds to 4.095V (min), 4.200V (typ), and 4.305V (max). The MAX6412UK42+T maintains this specification without external calibration components.

Does the MAX6412UK42+T support dual-voltage monitoring like some members of the MAX6412–MAX6420 family?

No, the MAX6412UK42+T does not support dual-voltage monitoring. It is a single-threshold supervisor with fixed 4.2V VCC monitoring and a manual reset input (MR). Dual-voltage capability is exclusive to the MAX6418/MAX6419/MAX6420 variants, which integrate both a factory-trimmed VCC threshold and an adjustable RESET IN input - a feature absent in the MAX6412UK42+T pinout and functional description.

Can the MAX6412UK42+T operate reliably at VCC = 1.2V, and what happens to the RESET output below 1V?

Yes, the MAX6412UK42+T is fully specified down to VCC = 1.0V and guarantees valid RESET output behavior (VOL ≤ 0.4V, VOH ≥ 0.8×VCC) at that level. Below 1.0V, RESET output drive strength degrades significantly; for applications requiring valid logic down to 0V, a 100kΩ pulldown resistor on the RESET pin is recommended - a design consideration explicitly documented for the MAX6412UK42+T in the datasheet's "Ensuring a Valid RESET" section.

What is the maximum value of the SRT capacitor for the MAX6412UK42+T, and what is the resulting timeout period?

The MAX6412UK42+T supports SRT capacitors up to 1500pF, yielding a maximum reset timeout period of 5.75ms (typical) at +25°C. This value is confirmed in the Electrical Characteristics table under "Reset Timeout Period" with CSRT = 1500pF. Larger capacitors increase timeout linearly per tRP = (2.71×10⁶)×CSRT + 275µs, but leakage and parasitic effects beyond 1500pF may degrade accuracy - a limit validated in the MAX6412UK42+T characterization data.

Is the MAX6412UK42+T AEC-Q100 qualified, and which stress test grades does it meet?

The MAX6412UK42+T itself is not explicitly listed as AEC-Q100 qualified in the provided documentation; however, the MAX6412–MAX6420 family includes /V-suffixed variants (e.g., MAX6412UK42/V+T) that are AEC-Q100 qualified. The +T suffix indicates lead-free RoHS compliance, while automotive qualification requires the /V designation. Therefore, standard MAX6412UK42+T is industrial-grade; for automotive use, the MAX6412UK42/V+T variant must be selected and sourced.