Maxim Integrated MAX809REXR-T Microprocessor Reset Circuit

The Maxim Integrated MAX809REXR-T is a compact, highly efficient microprocessor (µP) supervisory circuit designed to monitor power supplies in digital systems. It provides a significant level of protection to your digital devices by ensuring that the microprocessor is reset to a known state during power-up, power-down, or brown-out conditions. This component is essential for maintaining the integrity and reliable operation of microprocessor systems.

Featuring a 3-pin SOT-23 package, the MAX809REXR-T is an ideal choice for space-constrained applications. It offers a fixed-sense threshold voltage of 4.63V, tailored for monitoring 5V power supplies. When the monitored supply voltage drops below the factory-set reset threshold, the reset output is asserted, holding the connected µP in a reset state for a minimum of 140ms (typical). This timeout ensures that the system has sufficient time to stabilize before the µP begins operation.

One of the key advantages of the MAX809REXR-T is its low power consumption, drawing a quiescent current of only 17µA (typical). This makes it an excellent choice for portable and battery-operated applications where power efficiency is critical. Additionally, its wide operating temperature range from -40°C to +105°C ensures reliable performance across various environmental conditions.

The device also features an active-low RESET output, which is guaranteed to be in the correct state for VCC down to 1.0V. This feature enhances the safety of the systems it is integrated into by ensuring that the µP does not operate under unpredictable conditions that could lead to data corruption or system failures.

Overall, the Maxim Integrated MAX809REXR-T is a robust and reliable solution for system designers looking to enhance the operational safety of their digital systems. Its small footprint, low power consumption, and precision voltage monitoring capabilities make it an indispensable component for a wide range of applications, including computers, controllers, intelligent instruments, and portable/battery-powered equipment.