Analog Devices Inc./Maxim Integrated MAX6446UK26L-T

Overview

MAX6446UK26L-T from Maxim Integrated is a dual-input, fixed-threshold microprocessor supervisor IC with extended manual reset setup period, 2.625V VCC reset threshold, 6.72s MR1/MR2 assertion time, 140ms min reset timeout, and open-drain active-low RESET output in 5-pin SOT23 package. It monitors a single supply (VCC) and supports dual manual reset inputs for nuisance-free system reset in consumer electronics power management.

For engineers reviewing the MAX6446UK26L-T datasheet, MAX6446UK26L-T pinout, MAX6446UK26L-T application, or MAX6446UK26L-T equivalent, this page delivers verified electrical parameters, validated dual-MR timing behavior, confirmed SOT23-5 package mapping, real-world use cases in set-top boxes and modems, and two technically documented alternative parts with explicit functional and pinout differences.

Technical Context

The MAX6446UK26L-T implements a precision bandgap-based voltage monitor with factory-trimmed 2.625V ±0.075V reset threshold and 60ppm/°C tempco, paired with dual extended-setup manual reset inputs (MR1 and MR2) requiring simultaneous low assertion for ≥6.72s to trigger a one-shot 140ms–280ms RESET pulse. Its open-drain RESET output sinks up to 3.2mA at VCC ≥4.25V with VOL ≤0.4V and features guaranteed operation down to VCC = 1.0V.

Unlike immediate-reset supervisors, it uses internal RC timing and debouncing circuitry to reject transients <100ns and suppress false resets from switch bounce or ESD-induced glitches-validated by its 100ns MR2 glitch rejection spec and 200ns MR2-to-RESET delay. The device operates across –40°C to +85°C with 6µA typical supply current at 3.6V.

Key Specifications

Pinout & Package

MAX6446UK26L-T is housed in a RoHS-compliant 5-pin SOT23 package (package code U5-1, outline 21-0057), with 0.95mm pitch, 2.9mm × 1.6mm footprint, and thermal pad omitted. Pin 1 is marked via laser top-side dot.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6446UK26L-T, MAX6445UK26L-T offers push-pull drive for direct µP interfacing but forfeits open-drain flexibility, while MAX6448UK26L-T reduces reset security by removing MR2-making it suitable only for basic single-button systems.

Availability

MAX6446UK26L-T is available at Aetrix Electronics and suitable for set-top boxes, cable/DSL modems, and industrial HMIs requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for MAX6446UK26L-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 power management, sensing, and interface applications, with emphasis on high-reliability industrial and communications systems.

The MAX6443–MAX6452 family was engineered specifically for robust microprocessor supervision in consumer and industrial equipment where immunity to switch bounce, voltage transients, and brownout conditions is critical.

FAQ

What is the exact reset threshold voltage of MAX6446UK26L-T?

The MAX6446UK26L-T has a factory-trimmed VCC reset threshold of 2.625V, with a guaranteed range of 2.55V to 2.70V at +25°C and ±0.075V tolerance across –40°C to +85°C. This value is defined by the "26" suffix per Table 1 in the datasheet and applies exclusively to the VCC monitor-not RSTIN, which is unused in this variant.

Does MAX6446UK26L-T support dual manual reset functionality?

Yes, MAX6446UK26L-T supports dual manual reset inputs (MR1 and MR2), both requiring simultaneous low assertion for the full 6.72s setup period (L-suffix) to trigger the RESET output. This dual-MR architecture is explicitly confirmed in the Pin Description table and Manual Reset Input Options section for MAX6445/MAX6446 devices.

What package type and pin count does MAX6446UK26L-T use?

MAX6446UK26L-T uses a 5-pin SOT23 package (package code U5-1), with pinout: 1=GND, 2=VCC, 3=MR1, 4=MR2, 5=RESET. This is confirmed in the Ordering Information table and Pin Configurations diagram for MAX6445UK_ _ _-T and MAX6446UK_ _ _-T variants.

Is the RESET output of MAX6446UK26L-T push-pull or open-drain?

The RESET output of MAX6446UK26L-T is open-drain active-low, as specified in the Ordering Information table and Functional Diagram. It requires an external pullup resistor (minimum 20kΩ to VCC) and supports level-shifting to logic rails up to 6V-unlike push-pull variants such as MAX6445UK26L-T.

What is the minimum VCC voltage at which MAX6446UK26L-T guarantees valid RESET operation?

MAX6446UK26L-T guarantees valid RESET output logic down to VCC = 1.0V, as stated in the Features list and Electrical Characteristics table. Below 1.0V, RESET may become indeterminate; for operation down to 0V, a pulldown resistor is required-but only for push-pull versions, not the open-drain MAX6446UK26L-T.