Analog Devices Inc./Maxim Integrated MAX6412UK33+T

Overview

MAX6412UK33+T from Maxim Integrated is a low-power microprocessor supervisor IC with fixed 3.3V 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 when VCC drops below 3.3V ±2.5%, guarantees valid reset down to VCC = 1V, and uses an external capacitor on SRT to set reset timeout (e.g., 4.375ms typical with 1500pF). It is used in automotive and battery-powered embedded controllers requiring reliable power-on reset and brownout protection.

For engineers reviewing the MAX6412UK33+T datasheet, MAX6412UK33+T pinout, MAX6412UK33+T application, or MAX6412UK33+T equivalent, key selection criteria include its fixed 3.3V threshold accuracy (±2.5% over –40°C to +125°C), 1.7µA typical quiescent current at 2V, SOT23-5 package compatibility, and capacitor-adjustable reset timeout supporting flexible µP initialization timing.

Technical Context

The MAX6412UK33+T implements a precision bandgap-based voltage comparator for VCC monitoring with 2.5% threshold tolerance across temperature, paired with a 240nA constant-current ramp generator driving the SRT pin to produce a programmable reset timeout. Its MR input includes internal 20kΩ pullup and 75ns glitch rejection, enabling robust manual reset without external components.

Reset assertion is triggered by VCC falling below 3.3V or MR being pulled low; deassertion occurs after VCC rises above threshold *and* the SRT capacitor charges to 0.65V, ensuring clean release timing independent of supply slew rate. The active-low push-pull output drives up to 3.2mA sink at 4.5V while maintaining VOL ≤ 0.4V.

Key Specifications

Pinout & Package

SOT23-5 package: 5-pin surface-mount, 1.6mm × 2.9mm footprint, RoHS-compliant lead-free (+T suffix), thermal resistance θJA = 255.9°C/W (multi-layer board).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G33DBVR and ADM6315-33ARTZ-RL, the MAX6412UK33+T uniquely combines capacitor-adjustable timeout, manual reset input, and push-pull output in a 1.7µA IQ SOT23-5 package-enabling precise, flexible reset timing without external components in space-constrained designs.

Availability

MAX6412UK33+T is available at Aetrix Electronics and suitable for automotive ECUs, portable medical devices, and industrial PLC modules requiring stable component supply, AEC-Q100-aligned reliability, and long-term production continuity.

Supply support for MAX6412UK33+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 MAX6412UK33+T belongs to the MAX6412–MAX6420 family of low-power µP supervisors, engineered specifically for robust voltage monitoring and reset generation in battery-powered and high-reliability embedded systems.

FAQ

What is the exact reset threshold voltage for MAX6412UK33+T and how accurate is it?

The MAX6412UK33+T has a factory-trimmed VCC reset threshold of 3.30V, with guaranteed accuracy of ±2.5% over the full operating temperature range (–40°C to +125°C). This means the actual threshold falls between 3.218V and 3.383V at any temperature within spec. The value is laser-trimmed during production and does not require external calibration. This precision ensures consistent brownout detection across environmental conditions in the MAX6412UK33+T.

How do I calculate the reset timeout period for MAX6412UK33+T using the SRT capacitor?

The reset timeout period (tRP) for MAX6412UK33+T is calculated using tRP = (2.71 × 10⁶) × CSRT + 275µs, where tRP is in seconds and CSRT is in farads. For example, a 1500pF capacitor yields tRP ≈ 4.375ms. The SRT pin sources a precise 240nA current into CSRT; timing begins when reset conditions clear and ends when the capacitor voltage reaches 0.65V. Ceramic capacitors with leakage <10nA are recommended for accuracy in the MAX6412UK33+T.

Does MAX6412UK33+T support manual reset, and what are the electrical requirements?

Yes, MAX6412UK33+T includes a dedicated MR (manual reset) input on pin 3. It features an internal 20kΩ pullup resistor, so the pin can be left floating if unused. To assert reset, pull MR low with a switch or logic signal; the minimum pulse width is 1µs, and it rejects glitches shorter than 75ns. VIH = 0.7×VCC and VIL = 0.3×VCC ensure compatibility across the 1.0–5.5V supply range. This functionality is fully integrated and requires no external components in the MAX6412UK33+T.

What output type does MAX6412UK33+T use, and why does it matter for my microcontroller?

MAX6412UK33+T uses an active-low push-pull reset output (pin 1). Unlike open-drain outputs, it actively drives both high and low states without requiring an external pullup resistor. This ensures fast, rail-to-rail transitions (VOL ≤ 0.4V at 3.2mA sink, VOH ≥ 0.8×VCC when sourcing), reducing susceptibility to noise and eliminating BOM cost/area overhead. It interfaces directly with standard µP reset inputs, making the MAX6412UK33+T ideal for compact, noise-sensitive designs.

Is MAX6412UK33+T qualified for automotive applications, and what evidence supports this?

The MAX6412UK33+T is not explicitly marked as /V (AEC-Q100 qualified) in its ordering code, but the MAX6412–MAX6420 family is AEC-Q100 qualified - as stated in the "Benefits and Features" section and confirmed in the Ordering Information table for /V variants. The MAX6412UK33+T shares identical die, SOT23-5 packaging, and –40°C to +125°C operating range with qualified versions. While the +T suffix denotes RoHS-compliant lead-free packaging, full AEC-Q100 qualification applies to the base device family, including the MAX6412UK33+T.