Maxim Integrated MAX6421US29-T Microprocessor Supervisory Circuit

The MAX6421US29-T from Maxim Integrated is a compact, low-power microprocessor (µP) supervisory circuit designed to monitor power supplies in µP and digital systems. It provides excellent circuit reliability and low cost by eliminating external components and adjustments when used in systems with a 2.9V power supply voltage.

This supervisory circuit is ideal for use in a variety of applications, including portable/battery-powered equipment, computers, controllers, and intelligent instruments. Its primary function is to assert a reset signal whenever the VCC supply voltage declines below a preset threshold, ensuring that the µP starts up in a known state. The reset signal remains asserted for a period after VCC has risen above the reset threshold, providing a stable system reset for the µP to initialize properly.

The MAX6421US29-T features a factory-trimmed reset threshold voltage specifically set for a 2.9V supply, which is suitable for systems that operate with standard 3.3V power supplies but require a lower threshold to accommodate dips and brownouts. The reset output is available in both active-low and active-high configurations, making it versatile for interfacing with different µPs and digital logic.

Key features of the MAX6421US29-T include:

• Low supply current of 1.5µA (typical), which is crucial for battery-powered devices.
• Guaranteed reset valid to VCC = 1V, ensuring reliable operation during low voltage conditions.
• No external components are required, simplifying design and reducing system cost.
• Immune to short VCC transients, providing robust performance in noisy environments.
• Available in a space-saving SOT-143 package, ideal for applications where board space is at a premium.

With its precision voltage monitoring and low power consumption, the MAX6421US29-T is an excellent choice for designers looking to enhance system reliability without incurring significant power or space penalties. Maxim Integrated's commitment to quality ensures that this supervisory circuit will maintain system integrity and extend the life of the end product.