Maxim Integrated MAX690ACSE Microprocessor Supervisory Circuit

The MAX690ACSE from Maxim Integrated is a sophisticated 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 device ensures that the µP is fully reset during power-up, power-down, and brown-out conditions. The MAX690ACSE incorporates a watchdog timer that is activated by a chip-enable signal. If the µP fails to toggle this signal within the preset timeout period, the MAX690ACSE assumes that the µP is no longer in control and issues a reset command to ensure proper system recovery.

Key features of the MAX690ACSE include:

• Power Supply Monitoring: The device constantly monitors the power supply voltage and keeps the µP in the reset state during power-up, power-down, and brown-out conditions, ensuring stable system operation.
• Watchdog Timer: A watchdog timer helps prevent system failures by resetting the µP if it does not respond within a predetermined time frame, indicating a potential system malfunction or software lock-up.
• Manual Reset Input: An external manual reset input allows for a system reset to be triggered with an external pushbutton or logic signal.
• Voltage Monitor: The MAX690ACSE also includes a precise voltage monitor that guards against undervoltage conditions, which could lead to system instability.
• Low Power Consumption: The device is designed for low power consumption, making it suitable for use in power-sensitive applications.
• Small Package: Offered in a 16-pin narrow SO package, the MAX690ACSE is compact and suitable for space-constrained applications.

This supervisory circuit is ideal for use in microprocessor systems, computers, controllers, and intelligent instruments where reliable system operation is critical. The MAX690ACSE helps to ensure that systems start up in a known state every time and provides protection against system errors that can occur due to power disturbances or software glitches.

Maxim Integrated's commitment to quality and innovation makes the MAX690ACSE an essential component for system designers seeking to enhance the reliability and performance of their digital systems.