ON Semiconductor MAX809TTRG Microprocessor Reset Monitor

The ON Semiconductor MAX809TTRG is a compact, highly reliable microprocessor (μP) supervisory circuit designed to monitor power supplies in μP and digital systems. It provides a crucial function by delivering a precision output signal that indicates if the power supply voltage has dipped below a predetermined threshold, a condition that can potentially cause erratic operation in digital devices.

This supervisory circuit offers several key features that make it an essential component for enhancing system reliability. The MAX809TTRG has a fixed-sense threshold voltage of 4.63V, which is tailored to monitor 5V power supplies. When the monitored voltage falls below this threshold, the reset output is asserted (active low) and remains asserted until the voltage recovers above the threshold, plus a minimum reset timeout period. This ensures that the μP is held in reset for a sufficient time to allow for a proper restart, thus preventing code execution errors due to insufficient initialization time.

The device is housed in a small SOT-23 package, making it suitable for space-constrained applications. It operates over a wide temperature range of -40°C to +85°C, ensuring reliable performance under varying environmental conditions. The low supply current of 20μA (typical) makes the MAX809TTRG an energy-efficient choice for battery-powered applications.

Key features of the MAX809TTRG include:

• Precision monitoring of 5V power supplies
• Fixed threshold voltage of 4.63V
• Active-low reset output
• Minimum reset timeout of 140ms (typical)
• Low supply current of 20μA (typical)
• Operational temperature range from -40°C to +85°C
• Compact SOT-23 packaging

Applications for the MAX809TTRG are diverse and can include computers, controllers, intelligent instruments, portable/battery-powered equipment, and any system where a reliable reset signal is critical for proper operation. By integrating this supervisory circuit into your design, you can enhance the stability and dependability of your electronic systems, ensuring they operate as intended even under adverse conditions.