Maxim Integrated MAX691CJE+ Microprocessor Supervisory Circuit

The MAX691CJE+ from Maxim Integrated is a comprehensive microprocessor (µP) supervisory circuit that provides a multitude of features to enhance system reliability in µP and µP-based systems. This advanced circuit is designed to monitor power supplies and microprocessor activity in digital systems, providing essential protection and monitoring functions that are crucial for maintaining system integrity.

Key Features:

• Power Supply Monitoring: The MAX691CJE+ monitors the system voltage and ensures that it remains within acceptable thresholds. It provides a precision voltage monitor for +5V power supplies, ensuring that the microprocessor has a stable and reliable power source for operation.
• Microprocessor Reset: In the event of a power failure or other system fault, the device generates a reset signal to the microprocessor, effectively preventing code execution errors and data corruption. The reset output remains operational with VCC as low as 1V.
• Watchdog Timer: A built-in watchdog timer ensures that the microprocessor does not hang in an unresponsive state. If the microprocessor does not toggle the watchdog input within a preset time frame, the MAX691CJE+ will issue a system reset.
• Battery Backup Switching: For systems with battery backup, the MAX691CJE+ automatically switches to the backup battery when the main power supply fails, ensuring uninterrupted operation.
• Power Fail Warning: The device provides an early warning signal for impending power failure, allowing the system to take preemptive action to save data.
• Chip Enable Gating: The MAX691CJE+ can gate the chip enable signals to external memory, preventing spurious writes during power-up, power-down, or reset conditions.

Applications:

• Computers and Controllers
• Intelligent Instruments
• Critical µP Power Monitoring
• Portable/Battery-Powered Equipment

The MAX691CJE+ comes in a 16-pin JEDEC DIP package and operates over the temperature range of -40°C to +85°C. Its combination of power supply monitoring, microprocessor reset, battery backup switching, and other supervisory functions make it an indispensable component for enhancing system reliability and performance.