ON Semiconductor MAX809SQ463T1G Microprocessor Reset Circuit

The MAX809SQ463T1G is a compact, highly efficient microprocessor (µP) supervisory circuit designed by ON Semiconductor to monitor power supplies in digital systems. It provides a significant function by ensuring that the µP and its peripherals are reset properly during power-up, power-down, or brown-out conditions. This integrated circuit is essential for maintaining the integrity of system operations and preventing software corruption or data loss.

This device features a precision voltage sensor tailored for a 4.63V threshold, which is suitable for 5V-powered systems. When the monitored supply voltage drops below this threshold, the MAX809SQ463T1G asserts a reset signal, which remains asserted for a minimum of 140ms after the supply voltage rises above the reset threshold. This delay ensures that the system has sufficient time to stabilize before the processor starts its operation.

The MAX809SQ463T1G comes in a compact SOT-323 package, making it an excellent choice for space-constrained applications. Its low power consumption and wide operating temperature range from -40°C to +85°C make it suitable for demanding environments and portable applications.

Key features of the MAX809SQ463T1G include:

• Precision monitoring of 5V power supplies with a 4.63V threshold.
• Active-low RESET output with guaranteed valid down to 1V VCC.
• Minimum 140ms reset pulse width ensures proper system reset.
• Low supply current of 17µA (typical) for power-efficient operation.
• Immunity to short VCC transients to avoid false resets.
• Operating temperature range of -40°C to +85°C for reliability in diverse conditions.
• SOT-323 packaging for use in space-constrained applications.

Applications for the MAX809SQ463T1G are diverse and include portable devices, computers, controllers, intelligent instruments, and critical µP and µC power monitoring. This reset circuit is an essential component for any system that requires reliable operation and protection against unpredictable power supply conditions. With its precision voltage monitoring and robust design, the MAX809SQ463T1G from ON Semiconductor is a dependable choice for system designers looking to enhance the safety and performance of their digital systems.