Maxim Integrated MAX690ACSA+ Microprocessor Supervisory Circuit

The MAX690ACSA+ is a high-quality microprocessor (µP) supervisory circuit designed by Maxim Integrated 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 conjunction with +5V-powered circuits. This supervisory circuit is an ideal solution for managing system integrity through functions such as reset output during power-up, power-down, and brown-out conditions.

The MAX690ACSA+ ensures that the µP starts up in a known state. It features a reset output that remains asserted for a minimum of 100ms after VCC has reached the reset threshold level. This reset delay allows the power supply and µP to stabilize before the system start-up. The device also includes a watchdog timer that can be set by an external capacitor, providing a versatile timing range to keep the µP in check during normal operation.

Another key feature of the MAX690ACSA+ is its ability to perform battery backup switching for CMOS RAM, CMOS µP, or other low-power logic. A chip-enable gating function ensures that the memory remains in a high-impedance state during power failure, thus preventing any corruption of data.

Designed in a compact 8-pin SOIC package, the MAX690ACSA+ operates over a wide temperature range from -40°C to +85°C. It is suitable for a variety of applications, including computers, controllers, intelligent instruments, and critical µP power monitoring. The device's low supply current of 35µA (typical) makes it an energy-efficient choice for battery-powered applications.

Overall, the MAX690ACSA+ from Maxim Integrated is a reliable and versatile supervisory circuit that provides critical monitoring and control functions to enhance system stability and data integrity. Its ease of integration and robust feature set make it a popular choice among designers for ensuring proper operation and protection of their digital systems.