Diodes Incorporated APX809-44SAG-7 Microprocessor Reset Circuit

The APX809-44SAG-7 is a highly reliable, low-power microprocessor supervisory circuit manufactured by Diodes Incorporated. This essential component is designed to monitor the system voltage in microprocessor-based systems, providing a significant layer of protection against low voltage conditions which can lead to system errors and instability. The APX809-44SAG-7 ensures that the microprocessor and other critical system components reset properly during power-up, power-down, and brown-out conditions.

This device operates by asserting a reset signal whenever the V_CC supply voltage falls below a predetermined threshold. The reset signal remains asserted until the V_CC voltage returns to a stable condition above the threshold, ensuring the system has adequate time to return to a stable operating state before the processor begins execution. The reset delay time provided by the APX809-44SAG-7 is 240ms (minimum), allowing for a proper reset signal duration.

The APX809-44SAG-7 is available in a compact SOT-23 package, which is highly suitable for space-constrained applications. With its built-in hysteresis, it enhances noise immunity and prevents false resets, ensuring reliable operation even in noisy environments. The device supports a wide operating voltage range, making it versatile for various applications, including computers, controllers, intelligent instruments, and portable electronics.

Key features of the APX809-44SAG-7 include:

• Precision monitoring of 3V, 3.3V, and 5V supply voltages
• Low supply current of 17μA (typical)
• 240ms minimum reset timeout period
• Operating temperature range from -40°C to +85°C
• RoHS and Green compliant

The APX809-44SAG-7 is designed with an active-low, push-pull reset output, which provides a robust signal to connected components. Its precision voltage monitoring capability and low power consumption make it an excellent choice for energy-sensitive applications. By choosing the APX809-44SAG-7, designers can ensure system stability and a high level of protection for their microprocessor-based systems.