Analog Devices Inc./Maxim Integrated MAX6444US23L-T

Overview

MAX6444US23L-T from Maxim Integrated is a single-supply, fixed-threshold microprocessor reset supervisor IC with extended manual reset setup period (6.72s), 2.313V VCC reset threshold, open-drain active-low RESET output, and guaranteed operation down to VCC = 1.0V. It monitors a single supply voltage and asserts reset during brownout, power-up, or power-down events in consumer electronics and industrial embedded systems.

For engineers reviewing the MAX6444US23L-T datasheet, MAX6444US23L-T pinout, MAX6444US23L-T application, or MAX6444US23L-T equivalent, key selection considerations include its 6.72s manual reset hold time, 2.313V precision reset threshold, 210ms typical reset timeout, 6µA supply current, and SOT143-4 package compatibility with space-constrained PCB layouts.

Technical Context

The MAX6444US23L-T implements a precision bandgap-based voltage monitor with 60ppm/°C tempco and 2×VTH hysteresis for stable brownout detection. Its internal timing circuitry enforces a fixed 6.72s low assertion on MR1 before generating a one-shot 140ms–280ms RESET pulse, eliminating nuisance resets from momentary switch closures.

It features an open-drain RESET output rated for 50µA sink at VCC ≥ 1.0V and supports external pullup to voltages up to +6V. The device operates across the full industrial temperature range (−40°C to +85°C) with guaranteed valid reset logic down to VCC = 1.0V, and includes internal 50kΩ MR1 pullup to VCC.

Key Specifications

Pinout & Package

SOT143-4 package: 1.3mm × 2.9mm, 4-pin plastic surface-mount package with gull-wing leads, lead(Pb)-free compliant (−T suffix), rated for −40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6444US23L-T, MAX6316US23D3+ provides faster reset response but no extended manual reset protection, while TPS3808G33DBVR offers design flexibility in timeout configuration but requires external RC network for long hold times-neither matches the integrated 6.72s glitch-immune manual reset of MAX6444US23L-T.

Availability

MAX6444US23L-T is available at Aetrix Electronics and suitable for set-top boxes, DVD players, and cable modems requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.

Supply support for MAX6444US23L-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, sensing, and interface applications, with emphasis on reliability and integration for demanding environments.

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

FAQ

What is the exact reset threshold voltage of MAX6444US23L-T?

The MAX6444US23L-T has a factory-trimmed VCC reset threshold of 2.313V, with a guaranteed tolerance of ±0.075V over temperature. This value is defined by the "23" suffix per Table 1 and is optimized for monitoring standard 3.3V supply rails in consumer electronics applications.

How does the manual reset function work on MAX6444US23L-T?

The MAX6444US23L-T requires MR1 to be held low for a minimum of 6.72 seconds (L suffix) before asserting RESET. This extended setup period rejects short glitches and accidental presses. Once asserted, RESET remains low for at least 140ms, providing a clean one-shot reset pulse to the microprocessor.

Can MAX6444US23L-T operate reliably below 1.8V supply?

Yes - the MAX6444US23L-T is fully specified down to VCC = 1.0V and guarantees valid RESET output logic state (low when asserted) across that entire range. Its internal circuitry remains functional and the reset threshold remains accurate even at 1.0V, making it suitable for deep brownout scenarios.

What package type and dimensions does MAX6444US23L-T use?

The MAX6444US23L-T uses the SOT143-4 package: a 4-pin, gull-wing surface-mount package measuring 1.3mm × 2.9mm with 0.95mm pitch. It is lead(Pb)-free compliant (−T suffix) and qualified for operation from −40°C to +85°C.

Is an external pullup resistor required for the RESET output of MAX6444US23L-T?

Yes - because MAX6444US23L-T features an open-drain RESET output, an external pullup resistor (minimum 20kΩ to VCC) is mandatory to establish a defined high state when RESET is deasserted. Without it, the output floats and cannot drive a microprocessor's reset input correctly.