Maxim Integrated MAX708REPA Microprocessor Supervisory Circuit

The MAX708REPA from Maxim Integrated is a highly reliable microprocessor (µP) supervisory circuit designed to monitor power supplies and microprocessor activity in digital systems. It provides excellent circuit reliability and low cost by eliminating external components and adjustments when used in conjunction with +5V-powered circuits.

This supervisory circuit ensures that the µP is reset to a known state during power-up, power-down, or brown-out conditions. The MAX708REPA has an active-low RESET output, which is guaranteed to remain asserted for a minimum of 140ms after V_CC has risen above the reset threshold level. This feature provides a sufficient time margin for the power supply and the µP to stabilize before the processor can start executing instructions.

The device includes a watchdog timer that monitors the µP or microcontroller, ensuring it's operating correctly. If the µP fails to strobe the watchdog input within the preset timeout period, the MAX708REPA asserts a reset signal to restart the system. This helps to prevent system failures and enhances the overall reliability of the application it is used in.

Key features of the MAX708REPA include:

• Precision voltage monitor for +5V power supplies
• Fully integrated watchdog timer
• 140ms min power-on reset pulse width
• Active-low RESET output (RESET)
• 200ms min reset timeout period
• Low supply current of 17µA (typical)
• Wide supply voltage range: 4.5V to 5.5V
• Temperature range: -40°C to +85°C
• 8-pin DIP and SO packages available

The MAX708REPA is suitable for use in computers, controllers, intelligent instruments, critical µP and µC power monitoring, and portable/battery-powered equipment. Its small size and no external components requirement make it ideal for space-constrained applications. By providing an additional layer of protection for critical system functions, the MAX708REPA is an essential component for enhancing system reliability and preventing data loss.

Overall, Maxim Integrated's MAX708REPA is a robust and reliable solution for microprocessor system management, ensuring that systems remain operational and safe under a variety of conditions that could otherwise lead to system failure.