Maxim Integrated MAX809TUER Microprocessor Reset Circuit

The Maxim Integrated MAX809TUER is a compact, highly-reliable microprocessor (µP) supervisory circuit designed to monitor power supplies in digital systems. It provides a crucial function by ensuring that the µP and its peripherals are reset properly during power-up, power-down, and brown-out conditions. The MAX809TUER helps to prevent system errors and enhances the overall stability and reliability of electronic devices.

This supervisory circuit is tailored to maintain system integrity by monitoring the voltage level of the power supply. It asserts a reset signal to the connected µP if it detects that the voltage has fallen below a predefined threshold. The reset signal remains active until the supply voltage recovers and stabilizes above the threshold, plus for a specified period to ensure a proper system restart. This timeout period is internally set, providing a fixed delay that is invaluable for preventing the system from restarting prematurely.

The MAX809TUER is housed in a small SOT-23 package, making it an ideal choice for space-constrained applications. Its tiny footprint does not compromise its performance, as it boasts low supply current consumption, typically just 20µA, which is beneficial for portable and battery-operated devices where power efficiency is paramount.

Key features of the MAX809TUER include:

• Precision monitoring of 3V, 3.3V, and 5V power-supply voltages.
• 140ms (min) reset timeout period.
• Low power consumption, with a typical supply current of 20µA.
• Immunity to short voltage transients.
• Active-low RESET output.
• Capable of operating over a wide temperature range.

Applications for the MAX809TUER are diverse, ranging from computers and controllers to portable/battery-powered equipment, intelligent instruments, and embedded systems. Its robust design ensures that the connected microprocessor is kept in the reset state as long as the supply voltage remains below the designated threshold, thereby providing an additional layer of protection against unpredictable power supply conditions.

Overall, the Maxim Integrated MAX809TUER is a vital component for any system requiring reliable voltage monitoring and reset capabilities, ensuring that digital systems operate smoothly and consistently.