Analog Devices Inc./Maxim Integrated MAX6443US16L

Overview

The MAX6443US16L from Maxim Integrated is a single-supply, fixed-threshold microprocessor reset supervisor IC with extended manual reset setup period (6.72s), 1.575V VCC reset threshold, and active-low push-pull RESET output. It monitors VCC only, asserts reset when voltage drops below threshold, holds reset for 210ms (typ) after recovery, and guarantees valid operation down to VCC = 1.0V. Used in consumer electronics like DVD players and cable modems for reliable power-on/brownout reset control.

For engineers reviewing the MAX6443US16L datasheet, MAX6443US16L pinout, MAX6443US16L application, or MAX6443US16L equivalent, key selection considerations include its 6.72s manual reset hold time, 1.575V fixed reset threshold, SOT143-4 package, 6µA supply current, and immunity to short transients - critical for front-panel switch-driven reset systems requiring nuisance-reset suppression.

Technical Context

This device implements a precision bandgap-based voltage monitor for VCC with 60ppm/°C tempco and 2×VTH hysteresis. Its internal timing circuit enforces a fixed 6.72s low assertion on MR1 before generating a one-shot 140ms (min) RESET pulse, eliminating false triggers from momentary switch closures.

The push-pull RESET output drives low to ≤0.3V at 50µA sink while VCC ≥ 1.0V, and deasserts to ≥0.8×VCC when VCC ≥ 1.8V. MR1 features an internal 50kΩ pullup to VCC, enabling direct connection to mechanical switches without external components.

Key Specifications

Pinout & Package

MAX6443US16L is housed in a 4-pin SOT143 package with gull-wing leads, optimized for automated assembly and thermal performance in high-density layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6443US16L, MAX6443US16T offers faster manual reset response but reduced nuisance immunity, while MAX6444US16L trades integrated push-pull drive for flexible open-drain interfacing - both retain identical threshold, package, and temperature specification.

Availability

MAX6443US16L 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 RoHS-compliant packaging.

Supply support for MAX6443US16L 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 in industrial, communications, and consumer markets.

The MAX6443–MAX6452 family delivers ultra-low-power, high-immunity microprocessor supervisors targeting front-panel-controlled consumer electronics where robust manual reset functionality is essential.

FAQ

What is the exact reset threshold voltage of the MAX6443US16L?

The MAX6443US16L has a factory-set VCC reset threshold of 1.575V, with a tolerance of ±0.045V over the full -40°C to +85°C temperature range. This value is confirmed in the Electrical Characteristics table under "VCC Reset Threshold" for suffix "16", and is implemented using a precision bandgap reference with 60ppm/°C tempco. The MAX6443US16L guarantees valid reset assertion before most 1.8V µPs enter brownout.

How does the 6.72s manual reset setup period work on the MAX6443US16L?

The MAX6443US16L requires MR1 to be held low for a minimum of 6.72 seconds before asserting the RESET output - this is defined by the "L" suffix per Table 2. The internal timer ignores any MR1 transitions shorter than this period, effectively debouncing mechanical switches. Once asserted, RESET remains low for 140ms (min), then deasserts automatically. The MAX6443US16L does not require external RC networks or firmware intervention to achieve this timing.

Can the MAX6443US16L operate with VCC below 1.0V?

No - the MAX6443US16L guarantees valid RESET logic only down to VCC = 1.0V, as stated in the Absolute Maximum Ratings and Electrical Characteristics. Below 1.0V, the internal comparators and output driver cease reliable operation, and RESET may float or become indeterminate. For applications requiring reset validity down to 0V, a pulldown resistor on the push-pull RESET output is recommended, but this is outside the guaranteed operating range of the MAX6443US16L.

What package type and dimensions does the MAX6443US16L use?

The MAX6443US16L uses a 4-pin SOT143 package (package code U4+1), measuring 2.9mm × 1.3mm with 0.95mm height and 0.65mm lead pitch. Pin 1 is GND, Pin 2 is RESET, Pin 3 is MR1, and Pin 4 is VCC, per the top-view diagram in the datasheet. This RoHS-compliant, lead(Pb)-free package supports reflow soldering at +260°C and is optimized for high-volume automated assembly.

Is the RESET output of the MAX6443US16L push-pull or open-drain?

The MAX6443US16L features a push-pull RESET output, as confirmed by the Ordering Information table and Pin Description section. It actively drives low (≤0.3V at 50µA) and high (≥0.8×VCC) without requiring an external pullup resistor. This differs from the MAX6444US16L variant, which uses open-drain logic. The push-pull configuration simplifies design in single-supply 3.3V systems where the MAX6443US16L is commonly deployed.