Analog Devices Inc./Maxim Integrated MAX6343LUT

Overview

MAX6343LUT from Maxim Integrated is a precision microprocessor supervisory circuit with active-low open-drain reset output, factory-trimmed 4.63V VCC reset threshold, +1.25V power-fail comparator input, and guaranteed RESET assertion down to VCC = +1V. It monitors supply integrity in battery-powered systems and provides early power-fail warning for orderly shutdown in telecom and embedded control applications.

For engineers reviewing the MAX6343LUT datasheet, MAX6343LUT pinout, MAX6343LUT application, or MAX6343LUT equivalent, key selection criteria include its open-drain reset configuration, 100ms minimum reset pulse width, -40°C to +125°C operating range, SOT23-6 package compatibility, and dual-monitoring capability via PFI/PFO for multivoltage system supervision.

Technical Context

The MAX6343LUT integrates a precision voltage detector for VCC monitoring and an independent +1.25V reference-based comparator for PFI input, enabling simultaneous primary supply supervision and secondary rail monitoring (e.g., battery or auxiliary voltage). Its reset generator asserts RESET low for ≥100ms after VCC rises above 4.63V or MR transitions high.

Unlike push-pull variants, the MAX6343LUT features an open-drain RESET output requiring an external pull-up resistor-supporting level-shifting across multiple supply domains up to +5.5V-and includes debounced CMOS-compatible MR input with 1µs glitch rejection and 100ns minimum pulse width tolerance.

Key Specifications

Pinout & Package

MAX6343LUT is housed in a 6-pin SOT23-6 package (JEDEC MO-178AA), measuring 2.9mm × 1.6mm × 1.1mm, with gull-wing leads and lead-free (RoHS-compliant) construction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6342LUT-T and TPS3808G33DBVR, the MAX6343LUT uniquely combines open-drain reset flexibility with integrated power-fail warning-enabling both robust primary reset and secondary rail monitoring in one SOT23-6 device without external components.

Availability

MAX6343LUT is available at Aetrix Electronics and suitable for portable/battery-powered equipment, telecom equipment, and multivoltage systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6343LUT 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) is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and communications markets.

The MAX6342–MAX6345 family was designed specifically for reliable power-supply monitoring in space-constrained, wide-temperature embedded systems-emphasizing precision threshold accuracy, ultra-low power, and dual-supply visibility via integrated PFI/PFO.

FAQ

What is the exact reset threshold voltage of the MAX6343LUT?

The MAX6343LUT has a factory-trimmed VCC reset threshold of 4.63V with ±1.5% tolerance over the full -40°C to +125°C temperature range. This value is laser-trimmed during production and specified in the Electrical Characteristics table of the MAX6342–MAX6345 datasheet. The "L" suffix in MAX6343LUT explicitly denotes the 4.63V variant per Maxim's Selector Guide 1.

Does the MAX6343LUT require an external pull-up resistor on the RESET pin?

Yes, the MAX6343LUT features an active-low open-drain RESET output, which requires an external pull-up resistor to a valid logic-high voltage (up to +5.5V). A 10kΩ resistor is sufficient in most applications, selected to ensure logic-high recognition while accommodating all connected input leakage currents. This architecture enables level-shifting and wired-OR functionality not possible with push-pull outputs.

Can the MAX6343LUT monitor a negative supply voltage?

Yes, the MAX6343LUT can monitor a negative rail using the PFI input with an external resistor network and transistor stage as shown in Figure 8 of the datasheet. The +1.25V internal reference is referenced to GND, so PFI must remain above GND; the circuit converts negative voltage excursions into a rising PFI signal that triggers PFO high, which can then be fed to MR to assert reset. Accuracy depends on resistor tolerances and PFI threshold variation.

What is the minimum pulse width required on the MR input of the MAX6343LUT?

The MAX6343LUT requires a minimum MR low pulse width of 100ns to reliably trigger a reset event. Its internal debounce circuit rejects transients shorter than 1µs, but the minimum detectable active pulse is 100ns. This specification is verified across the full operating temperature range (-40°C to +125°C) and ensures compatibility with fast GPIO toggling or clean mechanical switch closure.

How does the MAX6343LUT ensure reset validity during deep brownout conditions?

The MAX6343LUT guarantees RESET output validity down to VCC = +1V - meaning the output remains at a defined logic level (low, when asserted) even as supply voltage collapses. This is achieved through proprietary low-voltage biasing and is confirmed in the Absolute Maximum Ratings and Electrical Characteristics tables. Unlike many supervisors that release reset unpredictably below 2V, the MAX6343LUT maintains deterministic behavior critical for data-safe shutdown.